Major depressive disorder (also known as
clinical depression,
major depression,
unipolar depression, or
unipolar disorder) is a mental disorder characterized by an all-encompassing
low moodIn psychology and psychiatry, depression is a state of low mood and aversion to activity. While most often described as a disease or dysfunction, there are also strong arguments for seeing depression as an adaptive defense mechanism....
accompanied by low
self-esteemSelf-esteem is a term used in psychology to reflect a person's overall evaluation or appraisal of his or her own worth.Self-esteem encompasses beliefs and emotions...
, and
loss of interest or pleasureIn psychology, anhedonia is an inability to experience pleasure from normally pleasurable life events such as eating, exercise, and social or sexual interaction....
in normally enjoyable activities. The term "major depressive disorder" was selected by the
American Psychiatric AssociationThe American Psychiatric Association is the main professional organization of psychiatrists and trainee psychiatrists in the United States, and the most influential worldwide. Its some 38,000 members are mainly American but some are international...
to designate this
symptom clusterIn medicine and psychology, the term syndrome refers to the association of several clinically recognizable features, signs , symptoms , phenomena or characteristics that often occur together, so that the presence of one feature alerts the physician to the presence of the others...
as a
mood disorderA mood disorder is the term given for a group of diagnoses in the Diagnostic and Statistical Manual of Mental Disorders classification system where a disturbance in the person's mood is hypothesized to be the main underlying feature...
in the 1980 version of the
Diagnostic and Statistical Manual of Mental DisordersThe Diagnostic and Statistical Manual of Mental Disorders is published by the American Psychiatric Association and provides diagnostic criteria for mental disorders...
(DSM-III) classification, and has become widely used since. The general term
depression is often used to describe the disorder, but as it can also be used to describe other
types of psychological depressionDepression is a term that can refer to a wide variety of abnormal variations in an individual's mood. If changes in an individual's mood are persistent and cause distress or impairment in functioning, then a mood disorder may be present...
, more precise terminology is preferred for the disorder in clinical and research use. Major depression is a disabling condition which adversely affects a person's family, work or school life, sleeping and eating habits, and general health. In the United States, approximately 3.4% of people with major depression commit
suicideSuicide is the intentional killing of one's self. Many dictionaries also note the metaphorical sense of "willful destruction of one's self-interest"...
, and up to 60% of people who commit suicide have depression or another mood disorder.
The diagnosis of major depressive disorder is based on the patient's self-reported experiences, behavior reported by relatives or friends, and a
mental status examThe mental status examination abbreviated MSE, is an important part of the clinical assessment process in psychiatric practice...
. There is no laboratory test for major depression, although physicians generally request tests for physical conditions that may cause similar symptoms. The most common time of onset is between the ages of 30 and 40 years, with a later peak between 50 and 60 years. Major depression is reported about twice as frequently in women as in men, and women attempt suicide more often, although men are at higher risk for succeeding.
Most patients are treated in the community with
antidepressantAn antidepressant is a psychiatric medication used to alleviate mood disorders, such as major depression and dysthymia. Drugs including the monoamine oxidase inhibitors , tricyclic antidepressants , tetracyclic antidepressants , selective serotonin reuptake inhibitors , and serotonin-norepinephrine...
medication and some with
psychotherapyPsychotherapy or personal counseling with a psychotherapist, is an intentional interpersonal relationship used by trained psychotherapists to aid a client or patient in problems of living.It aims to increase the individual's sense of their own well-being...
or counseling. Hospitalization may be necessary in cases with associated
self-neglectSelf-neglect is a behavioural condition in which an individual neglects to attend to their basic needs, such as personal hygiene, appropriate clothing, feeding, or tending appropriately to any medical conditions they have. Extreme self-neglect can be known as Diogenes syndrome.-Causes of...
or a significant risk of harm to self or others. A minority are treated with
electroconvulsive therapyElectroconvulsive therapy , also known as electroshock, is a well-established, albeit controversial, psychiatric treatment in which seizures are electrically induced in anesthetized patients for therapeutic effect...
(ECT), under a short-acting
general anaestheticA general anaesthetic drug is an anaesthetic drug that brings about a reversible loss of consciousness...
. The course of the disorder varies widely, from one episode lasting months to a lifelong disorder with recurrent
major depressive episodeA major depressive episode is the main symptom of major depressive disorder. The description has been formalised in psychiatric diagnostic criteria such as the DSM-IV and ICD-10, and is characterized by severe, highly persistent depression, and a loss of interest or pleasure in everyday activities,...
s. Depressed individuals have shorter
life expectanciesLife expectancy is the expected number of years of life remaining at a given age. It is denoted by e
x, which means the average number of subsequent years of life for someone now aged x, according to a particular mortality experience...
than those without depression, in part because of greater susceptibility to medical illnesses and suicide. Current and former patients may be
stigmatizedSocial stigma is severe social disapproval of personal characteristics or beliefs that are perceived to be against cultural norms. Stigma is often based on ignorance, irrational or unfounded fears, mass hysteria, lack of education, or a lack of information pertaining to a particular person or group...
.
The understanding of the nature and causes of depression has evolved over the centuries, though this understanding is incomplete and many aspects of depression are still the subject of discussion and research.
PsychologicalPsychology is an academic and applied discipline involving the systematic, and sometimes scientific, study of human or animal mental functions and behavior...
,
psycho-socialSocial psychology is a type of social science that is concerned with individuals' thoughts, feelings and behavior as they affect or are affected by other individuals...
,
hereditaryHeredity is the passing of traits to offspring . This is the process by which an offspring cell or organism acquires or becomes predisposed to the characteristics of its parent cell or organism. Through heredity, variations exhibited by individuals can accumulate and cause a species to evolve...
,
evolutionIn biology, evolution is change in the genetic material of a population of organisms from one generation to the next. Though changes produced in any one generation are normally small, differences accumulate with each generation and can, over time, cause substantial changes in the population, a...
ary and
biologicalBiology is the natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy...
causes have been proposed. Psychological treatments are based on theories of personality, interpersonal communication, and
learningIn psychology and education, a common definition of learning is a process that brings together cognitive, emotional, and environmental influences and experiences for acquiring, enhancing, or making changes in one's knowledge, skills, values, and world views . Learning as a process focuses on what...
. Most biological theories focus on the
monoamineMonoamine neurotransmitters are neurotransmitters and neuromodulators that contain one amino group that is connected to an aromatic ring by a two-carbon chain...
chemicals
serotoninSerotonin is a monoamine neurotransmitter. It is found extensively in the gastrointestinal tract of animals, and about 80 to 90 percent of the human body's total serotonin is located in the enterochromaffin cells in the gut, where it is used to regulate intestinal movements...
,
norepinephrineNoradrenaline or norepinephrine is a catecholamine with dual roles as a hormone and a neurotransmitter....
, and
dopamineDopamine is a neurotransmitter occurring in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this phenethylamine functions as a neurotransmitter, activating the five types of dopamine receptors — D
1, D
2, D
3, D
4, and...
, which are naturally present in the
brainThe human brain is the center of the human nervous system and is a highly complex organ. Enclosed in the cranium, it has the same general structure as the brains of other mammals, but is over three times as large as the brain of a typical mammal with an equivalent body size...
and assist communication between
nerve cellsA neuron is an excitable cell in the nervous system that processes and transmits information by electrochemical signaling. Neurons are the core components of the brain, the vertebrate spinal cord, the invertebrate ventral nerve cord, and the peripheral nerves...
. Monoamines have been implicated in depression, and most antidepressants work to increase the active levels of at least one.
Symptoms and signs
Major depression is a serious illness that affects a person's family and personal relationships, work or school life, sleeping and eating habits, and general health. Its impact on functioning and well-being has been equated to that of chronic medical conditions such as
diabetesDiabetes mellitus —often referred to simply as diabetes—is a condition in which the body either does not produce enough, or does not properly respond to, insulin, a hormone produced in the pancreas. Insulin enables cells to absorb glucose in order to turn it into energy...
.
A person suffering a
major depressive episodeA major depressive episode is the main symptom of major depressive disorder. The description has been formalised in psychiatric diagnostic criteria such as the DSM-IV and ICD-10, and is characterized by severe, highly persistent depression, and a loss of interest or pleasure in everyday activities,...
usually exhibits a very low mood, which pervades all aspects of life, and an
inability to experience pleasureIn psychology, anhedonia is an inability to experience pleasure from normally pleasurable life events such as eating, exercise, and social or sexual interaction....
in activities that formerly were enjoyed. Depressed people may be preoccupied with, or
ruminateRumination is a way of responding to distress that involves repetitively and passively focusing on the symptoms of distress, and on its possible causes and consequences. Rumination is more common in people who are pessimistic, neurotic, and who have negative attributional styles. The tendency to...
over, thoughts and feelings of worthlessness, inappropriate guilt or regret, helplessness, hopelessness, and self-hatred. In severe cases, depressed people may have symptoms of
psychosisPsychosis literally means abnormal condition of the mind, and is a generic psychiatric term for a mental state often described as involving a "loss of contact with reality"...
. These symptoms include
delusionA delusion, in everyday language, is a fixed belief that is either false, fanciful, or derived from deception. Psychiatry defines the term more specifically as a belief that is pathological...
s or, less commonly,
hallucinationA hallucination, in the broadest sense, is a perception in the absence of a stimulus. In a stricter sense, hallucinations are defined as perceptions in a conscious and awake state in the absence of external stimuli which have qualities of real perception, in that they are vivid, substantial, and...
s, usually of an unpleasant nature. Other symptoms of depression include poor concentration and memory (especially in those with melancholic or psychotic features), withdrawal from social situations and activities, reduced
sex driveLibido in its common usage means sexual desire; however, more technical definitions, such as those found in the work of Carl Jung, are more general, referring to libido as the free creative—or psychic—energy an individual has to put toward personal development or individuation.- History of the...
, and thoughts of death or suicide.
InsomniaInsomnia is a symptom of any of several sleep disorders, characterized by persistent difficulty falling asleep or staying asleep despite the opportunity. Insomnia is a symptom, not a stand-alone diagnosis or a disease. By definition, insomnia is "difficulty initiating or maintaining sleep, or both"...
is common among the depressed. In the typical pattern, a person wakes very early and is unable to get back to sleep.
HypersomniaHypersomnia is a disorder characterized by excessive amounts of sleepiness.From the website of the U.S. National Institute of Neurological Disorders and Stroke :-Causes:...
, or oversleeping, is less common. Appetite often decreases, with resulting weight loss, although increased appetite and weight gain occasionally occur. The person may report multiple physical symptoms such as fatigue, headaches, or digestive problems; physical complaints are the most common presenting problem in developing countries, according to the
World Health Organization'sThe World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health...
criteria for depression. Family and friends may notice that the person's behavior is either
agitatedPsychomotor agitation is a series of unintentional and purposeless motions that stem from mental tension and anxiety of an individual. This includes pacing around a room, wringing one's hands, pulling off clothing and putting it back on and other similar actions...
or
lethargicPsychomotor retardation or "Psychomotor Slowing" comprises a slowing down of thought and a reduction of physical movements in an individual. This is most commonly seen in people with major depression , and indicates a certain degree of severity...
.
Depressed children often display an irritable rather than a depressed mood, and show varying symptoms depending on age and situation. Most exhibit a loss of interest in school and a decline in academic performance. They may be described as clingy, demanding, dependent, or insecure. Diagnosis may be delayed or missed when symptoms are interpreted as normal moodiness. Depression may also coincide with
attention-deficit hyperactivity disorderAttention-deficit hyperactivity disorder is a neurobehavioral developmental disorder. ADHD is primarily characterized by "the co-existence of attentional problems and hyperactivity, with each behavior occurring infrequently alone." While symptoms may appear to be innocent and merely annoying...
(ADHD), complicating the diagnosis and treatment of both.
Older depressed persons may have cognitive symptoms of recent onset, such as forgetfulness, and a more noticeable slowing of movements. Depression often coexists with physical disorders common among the elderly, such as
strokeA stroke is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by thrombosis or embolism or due to a hemorrhage...
, other cardiovascular diseases,
Parkinson's diseaseParkinson's disease is a degenerative disorder of the central nervous system that often impairs the sufferer's motor skills, speech, and other functions....
, and chronic obstructive pulmonary disease.
Causes
The
biopsychosocial modelThe biopsychosocial model is a general model or approach that posits that biological, psychological , and social factors, all play a significant role in human functioning in the context of disease or illness...
proposes that biological, psychological, and social factors all play a role to varying degrees in causing depression. The diathesis–stress model posits that depression results when a preexisting vulnerability, or diathesis, is activated by stressful life events. The preexisting vulnerability can be either
geneA gene is the basic unit of heredity in a living organism. All living things depend on genes. Genes hold the information to build and maintain their cells and pass genetic traits to offspring...
tic, implying an interaction between
nature and nurtureThe nature versus nurture debates concern the relative importance of an individual's innate qualities versus personal experiences The nature versus nurture debates concern the relative importance of an individual's innate qualities ("nature", i.e. nativism, or innatism) versus personal experiences...
, or
schematicA schema , in psychology and cognitive science, is a mental structure that represents some aspect of the world. Schemata were initially introduced into psychology and education through the work of the British psychologist Sir Frederic Bartlett...
, resulting from views of the world learned in childhood. These interactive models have gained
empiricalThe word empirical denotes information gained by means of observation, experience, or experiment. A central concept in science and the scientific method is that all evidence must be empirical, or empirically based, that is, dependent on evidence or consequences that are observable by the senses...
support. For example, researchers in
New ZealandNew Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses , and numerous smaller islands, most notably Stewart Island/Rakiura and the Chatham Islands. The indigenous Māori named New Zealand Aotearoa, commonly translated as The Land of the Long White Cloud...
took a
prospective approachA prospective cohort study is a cohort study that follows over time a group of similar individuals who differ with respect to certain factors under study, in order to determine how these factors affect rates of a certain outcome...
to studying depression, by
documenting over timeA longitudinal study is a correlational research study that involves repeated observations of the same items over long periods of time — often many decades. It is a type of observational study. Longitudinal studies are often used in psychology to study developmental trends across the life...
how depression emerged among an initially
normalIn behavior, normal refers to a lack of significant deviation from the average. The phrase "not normal" is often applied in a negative sense Abnormality varies greatly in how pleasant or unpleasant this is for other people.The Oxford English Dictionary defines "normal" as 'conforming to a standard'...
cohortIn statistics and demography, a cohort is a group of subjects who have shared a particular experience during a particular time span . Cohorts may be tracked over extended periods of time in a cohort study. The cohort can be modified by censoring, i.e...
of people. The researchers concluded that variation among the
serotonin transporterThe serotonin transporter is a monoamine transporter protein.This protein is an integral membrane protein that transports the neurotransmitter serotonin from synaptic spaces into presynaptic neurons. This transport of serotonin by the SERT protein terminates the action of serotonin and recycles it...
(5-HTT) gene
affects the chancesIn statistics, moderation occurs when the relationship between two variables depends on a third variable. The third variable is referred to as the moderator variable or simply the moderator...
that people who have dealt with very stressful life events will go on to experience depression. Specifically, depression may follow such events, but seems more likely to appear in people with one or two short
alleleAn allele is one of a series of different forms of a gene. The word is a short form of allelomorph , which was used in the early days of genetics to describe variant forms of a gene detected as different phenotypes...
s of the 5-HTT gene.
A
SwedishSweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe...
study estimated the
heritabilityIn genetics, Heritability is the proportion of phenotypic variation in a population that is attributable to genetic variation among individuals. Variation among individuals may be due to genetic and/or environmental factors...
of depression—the degree to which individual differences in occurrence are associated with genetic differences—to be approximately 40% for women and 30% for men, and
evolutionary psychologistsEvolutionary psychology attempts to explain psychological traits—such as memory, perception, or language—as adaptations, that is, as the functional products of natural selection or sexual selection. Adaptationist thinking about physiological mechanisms, such as the heart, lungs, and immune system,...
have proposed that the genetic basis for depression lies deep in the history of
naturally selectedNatural selection is the process by which heritable traits that make it more likely for an organism to survive and successfully reproduce become more common in a population over successive generations...
adaptationAdaptation is the process whereby a population becomes better suited to its habitat. This process takes place over many generations, and is one of the basic phenomena of biology....
s. A substance-induced mood disorder resembling major depression has been causally linked to long-term
drug useDrugs can be used in many different ways, as detailed below.-Medication:People can use drugs to relieve pain or discomfort or to cure or prevent disease.-Recreational drug use:...
or
abuseDrug abuse has a huge range of definitions related to taking a psychoactive drug or performance enhancing drug for a non-therapeutic or non-medical effect. All of these definitions imply a negative judgement of the drug use in question...
, or to
withdrawalWithdrawal can refer to any sort of separation, but is most commonly used to describe the group of symptoms that occurs upon the abrupt discontinuation/separation or a decrease in dosage of the intake of medications, recreational drugs, and/or alcohol...
from certain
sedativeA sedative is a substance that induces sedation by reducing irritability or excitement.At higher doses it may result in slurred speech, staggering gait, poor judgment, and slow, uncertain reflexes...
and
hypnotic drugsHypnotic drugs are a class of psychoactives whose primary function is to induce sleep and to be used in the treatment of insomnia and in surgical anesthesia. Because drugs in this class generally produce dose-dependent effects, ranging from anxiolysis to production of unconsciousness, they are...
.
Monoamine hypothesis
Most
antidepressantAn antidepressant is a psychiatric medication used to alleviate mood disorders, such as major depression and dysthymia. Drugs including the monoamine oxidase inhibitors , tricyclic antidepressants , tetracyclic antidepressants , selective serotonin reuptake inhibitors , and serotonin-norepinephrine...
medications increase the levels of one or more of the monoamines—the neurotransmitters
serotoninSerotonin is a monoamine neurotransmitter. It is found extensively in the gastrointestinal tract of animals, and about 80 to 90 percent of the human body's total serotonin is located in the enterochromaffin cells in the gut, where it is used to regulate intestinal movements...
,
norepinephrineNoradrenaline or norepinephrine is a catecholamine with dual roles as a hormone and a neurotransmitter....
and
dopamineDopamine is a neurotransmitter occurring in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this phenethylamine functions as a neurotransmitter, activating the five types of dopamine receptors — D
1, D
2, D
3, D
4, and...
—in the
synaptic cleftChemical synapses are specialized junctions through which neurons signal to each other and to non-neuronal cells such as those in muscles or glands. Chemical synapses allow neurons to form circuits within the central nervous system. They are crucial to the biological computations that underlie...
between neurons in the brain. Some medications affect the monoamine receptors directly.
Serotonin is hypothesized to help regulate other neurotransmitter systems; decreased serotonin activity may allow these systems to act in unusual and erratic ways. According to this "permissive hypothesis", depression arises when low serotonin levels promote low levels of norepinephrine, another monoamine neurotransmitter. Some antidepressants enhance the levels of norepinephrine directly, whereas others raise the levels of dopamine, a third monoamine neurotransmitter. These observations gave rise to the monoamine hypothesis of depression. In its contemporary formulation, the monoamine hypothesis postulates that a deficiency of certain neurotransmitters is responsible for the corresponding features of depression: "Norepinephrine may be related to alertness and energy as well as anxiety, attention, and interest in life; [lack of] serotonin to anxiety, obsessions, and compulsions; and dopamine to attention, motivation, pleasure, and reward, as well as interest in life." The proponents of this theory recommend the choice of an antidepressant with mechanism of action that impacts the most prominent symptoms. Anxious and irritable patients should be treated with SSRIs or
norepinephrine reuptake inhibitorA norepinephrine reuptake inhibitor or adrenergic reuptake inhibitor , is a type of drug which acts as a reuptake inhibitor for the neurotransmitters norepinephrine and epinephrine by blocking the action of the norepinephrine transporter...
s, and those experiencing a loss of energy and enjoyment of life with norepinephrine- and dopamine-enhancing drugs.
In the past two decades, research has revealed multiple limitations of the monoamine hypothesis, and its explanatory inadequacy has been criticized within the psychiatric community. Intensive investigation has failed to find convincing evidence of a primary dysfunction of a specific monoamine system in patients with major depressive disorders. The medications
tianeptineTianeptine is a selective serotonin reuptake enhancer drug used for treating Major depressive episodes . Unlike conventional tricyclic antidepressants, tianeptine enhances the reuptake of serotonin instead of inhibiting it, opposite to the action of SSRIs...
and
opipramolOpipramol is a psychoactive drug widely used as an anxiolytic in Germany. Although it is a member of the tricyclic antidepressants , opipramol's primary mechanism of action is much different in comparison...
have long been known to have antidepressant properties despite the fact that the former is a serotonin reuptake enhancer and the latter has no effect on the monoamine system. Experiments with pharmacological agents that cause depletion of monoamines have shown that this depletion does not cause depression in healthy people nor does it worsen symptoms in depressed patients—although an intact monoamine system is necessary for antidepressants to achieve therapeutic effectiveness. According to an essay published by the
Public Library of ScienceThe Public Library of Science is a nonprofit open-access scientific publishing project aimed at creating a library of open access journals and other scientific literature under an open content license. It launched its first journal, PLoS Biology, in October 2003 and has steadily created another...
(PLoS), the monoamine hypothesis, already limited, has been further oversimplified when presented to the general public as a mass marketing tool.
Other theories
MRI scans of patients with depression have reported a number of differences in brain structure compared to those without the illness. Although there is some inconsistency in the results, meta-analyses have shown there is evidence for smaller
hippocampalThe hippocampus is a major component of the brains of humans and other mammals. It belongs to the limbic system and plays important roles in long-term memory and spatial navigation. Like the cerebral cortex, with which it is closely associated, it is a paired structure, with mirror-image halves in...
volumes and increased numbers of hyperintensive lesions. Hyperintensities have been associated with patients with a late age of onset, and have led to the development of the theory of
vascular depressionSubcortical ischemic depression, also known as vascular depression is a medical condition most commonly seen in elderly depressed patients. Late onset depression is increasingly seen as a distinct variety of depression, and is commonly detected with an MRI...
.
There may be a link between depression and
neurogenesisNeurogenesis is the process by which neurons are generated. Most active during pre-natal development, neurogenesis is responsible for populating the growing brain.-Adult neurogenesis:...
of the hippocampus, a center for both mood and memory. Loss of hippocampal
neuronA neuron is an excitable cell in the nervous system that processes and transmits information by electrochemical signaling. Neurons are the core components of the brain, the vertebrate spinal cord, the invertebrate ventral nerve cord, and the peripheral nerves...
s is found in some depressed individuals and correlates with impaired memory and dysthymic mood. Drugs may increase serotonin levels in the brain, stimulating neurogenesis and thus increasing the total mass of the hippocampus. This increase may help to restore mood and memory. Similar relationships have been observed between depression and an area of the
anterior cingulate cortexThe Anterior cingulate cortex is the frontal part of the cingulate cortex, that resembles a "collar" form around the corpus callosum, the fibrous bundle that relays neural signals between the right and left cerebral hemispheres of the brain....
implicated in the modulation of emotional behavior. One of the
neurotrophinNeurotrophins are a family of proteins that induce the survival, development and function of neurons.They belong to a class of growth factors, secreted proteins, which are capable of signaling particular cells to survive, differentiate, or grow. Growth factors such as neurotrophins that promote the...
s responsible for neurogenesis is the
brain-derived neurotrophic factorBrain-derived neurotrophic factor also known as BDNF is a protein which in humans is encoded by the BDNF gene. BDNF is a member of the "neurotrophin" family of growth factors – which are related to the canonical "Nerve Growth Factor", NGF...
(BDNF). The level of BDNF in the blood plasma of depressed subjects is drastically reduced (more than threefold) as compared to the norm. Antidepressant treatment increases the blood level of BDNF. Although decreased plasma BDNF levels have been found in many other disorders, there is some evidence that BDNF is involved in the cause of depression and the mechanism of action of antidepressants.
Major depression may also be caused in part by an overactive
hypothalamic-pituitary-adrenal axisThe hypothalamic-pituitary-adrenal axis , also known as thelimbic-hypothalamic-pituitary-adrenal axis , is a complex set of direct influences and feedback interactions among the hypothalamus , the pituitary gland , and the adrenal glands...
(HPA axis) that is similar to the neuro-endocrine response to stress. Investigations reveal increased levels of the hormone
cortisolCortisol is a corticosteroid hormone or glucocorticoid produced by the adrenal cortex, that is part of the adrenal gland . It is usually referred to as the "stress hormone" as it is involved in response to stress and anxiety, controlled by CRH...
and enlarged pituitary and adrenal glands, suggesting disturbances of the
endocrine systemThe endocrine system is a system of glands that involve the release of extracellular signaling molecules known as hormones.The endocrine system is instrumental in regulating metabolism, growth, development, puberty, tissue function, internal environment and also plays a part in determining...
may play a role in some psychiatric disorders, including major depression. Oversecretion of
corticotropin-releasing hormoneCorticotropin-releasing hormone , originally named corticotropin-releasing factor , and also called corticoliberin, is a polypeptide hormone and neurotransmitter involved in the stress response....
from the
hypothalamusThe hypothalamus is a portion of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions of the hypothalamus is to link the nervous system to the endocrine system via the pituitary gland ....
is thought to drive this, and is implicated in the cognitive and arousal symptoms.
Depression may be related to abnormalities in the
circadian rhythmA circadian rhythm is a roughly-24-hour cycle in the biochemical, physiological or behavioral processes of living entities, including plants, animals, fungi and cyanobacteria...
, or biological clock. For example, the REM stage of sleep, the one in which
dreamDreams are a succession of images, thoughts, or emotions passing through the mind during sleep. The content and purpose of dreams are not fully understood, though they have been a topic of speculation and interest throughout recorded history. The scientific study of dreams is known as...
ing occurs, may be quick to arrive and intense in depressed people. REM sleep depends on decreased serotonin levels in the
brain stemThe brainstem is the lower part of the brain, adjoining and structurally continuous with the spinal cord. The brain stem provides the main motor and sensory innervation to the face and neck via the cranial nerves...
, and is impaired by compounds, such as antidepressants, that increase serotoninergic tone in brain stem structures. Overall, the serotonergic system is least active during sleep and most active during wakefulness. Prolonged wakefulness due to
sleep deprivationSleep deprivation, a sleep disorder characterized by having too little sleep, can be either chronic or acute. Long-term sleep deprivation causes death in lab animals...
activates serotonergic neurons, leading to processes similar to the therapeutic effect of antidepressants, such as the selective serotonin reuptake inhibitors (SSRIs). Depressed individuals can exhibit a significant lift in mood after a night of sleep deprivation. SSRIs may directly depend on the increase of central serotonergic neurotransmission for their therapeutic effect, the same system that impacts cycles of sleep and wakefulness.
Research on the effects of
light therapyLight therapy or phototherapy consists of exposure to daylight or to specific wavelengths of light using lasers, light-emitting diodes, fluorescent lamps, dichroic lamps or very bright, full-spectrum light, for a prescribed amount of time and, in some cases, at a specific time of day. Light therapy...
on treating
seasonal affective disorderSeasonal Affective Disorder , also known as winter depression or winter blues, is a mood disorder in which people who have normal mental health throughout most of the year experience depressive symptoms in the winter or, less frequently, in the summer, spring or fall, repeatedly, year after year...
suggests that light deprivation is related to decreased activity in the serotonergic system and to abnormalities in the sleep cycle, particularly insomnia. Exposure to light also targets the serotonergic system, providing more support for the important role this system may play in depression. Sleep deprivation and
light therapyLight therapy or phototherapy consists of exposure to daylight or to specific wavelengths of light using lasers, light-emitting diodes, fluorescent lamps, dichroic lamps or very bright, full-spectrum light, for a prescribed amount of time and, in some cases, at a specific time of day. Light therapy...
both target the same brain neurotransmitter system and brain areas as antidepressant drugs, and are now used clinically to treat depression. Light therapy, sleep deprivation and sleep time displacement (sleep phase advance therapy) are being used in combination quickly to interrupt a deep depression in hospitalized patients.
The hormone
estrogenEstrogens are a group of steroid compounds, named for their importance in the estrous cycle, and functioning as the primary female sex hormone, their name comes from estrus/oistros + gen/gonos = to generate.Estrogens are used as part of some oral contraceptives, in estrogen replacement...
has been implicated in depressive disorders due to the increase in risk of depressive episodes after puberty, the antenatal period, and reduced rates after
menopauseMenopause is the time in a woman’s life when menstruation ends. It is part of a biological process that begins, for most women, in their mid-fifties. During this time, the ovaries gradually produce lower levels of natural sex hormones—estrogen and progesterone...
. Conversely, the premenstrual and postpartum periods of low estrogen levels are also associated with increased risk. The use of estrogen has been under-researched, and although some small trials show promise in its use to prevent or treat depression, the evidence for its effectiveness is not strong. Estrogen replacement therapy has been shown to be beneficial in improving mood in perimenopause, but it is unclear if it is merely the menopausal symptoms that are being reversed.
Other research has explored potential roles of molecules necessary for overall
cellularThe cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of an organism that is classified as living, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos...
functioning:
cytokineCytokines are any of a number of substances that are secreted by specific cells of the immune system which carry signals locally between cells, and thus have an effect on other cells. They are a category of signaling molecules that are used extensively in cellular communication. They are proteins,...
s and
essential nutrientAn essential nutrient is a nutrient required for normal body functioning that either cannot be synthesized by the body at all, or cannot be synthesized in amounts adequate for good health , and thus must be obtained from a dietary source. Some categories of essential nutrients include vitamins,...
s. The symptoms of major depressive disorder are nearly identical to those of
sickness behaviorthumb|350px|right|[[Michael Peter Ancher|Ancher, Michael]], "The Sick Girl", 1882, [[Statens Museum for Kunst]]Sickness behavior is a coordinated set of adaptive behavioral changes that develop in ill individuals during the course of an infection....
, the response of the body when the
immune systemAn immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumour cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
is fighting an
infectionAn infection is the detrimental colonization of a host organism by a foreign species. In an infection, the infecting organism seeks to utilize the host's resources to multiply, usually at the expense of the host. The infecting organism, or pathogen, interferes with the normal functioning of the...
. This raises the possility that depression can result from a maladaptive manifestation of sickness behavior as a result of abnormalities in circulating cytokines. Deficiencies in certain essential dietary nutrients, particularly
vitamin B12Vitamin B12 is a water soluble vitamin with a key role in the normal functioning of the brain and nervous system, and for the formation of blood. It is one of the eight B vitamins...
and
folic acidFolic acid and folate , as well as pteroyl-L-glutamic acid and pteroyl-L-glutamate, are forms of the water-soluble vitamin B
9...
, have been associated with depression; other agents such as the elements copper and
magnesiumMagnesium is an essential element in biological systems. Magnesium occurs typically as the Mg
2+ ion. It is an essential mineral nutrient for life and is present in every cell type in every organism. For example, ATP , the main source of energy in cells, must be bound to a magnesium ion...
, and
vitamin AVitamin A is linked to a family of similarly shaped molecules, the retinoids, which complete the remainder of the vitamin sequence. Its important part is the retinyl group, which can be found in several forms. In foods of animal origin, the major form of vitamin A is an ester, primarily retinyl...
have also been implicated.
Psychological
Various aspects of
personalityPersonality psychology is a branch of psychology that studies personality and individual differences.Its areas of focus include:* Constructing a coherent picture of a person and his or her major psychological processes...
and its
developmentAn individual's personality is an aggregate conglomeration of decisions we've made throughout our lives . There are inherent natural, genetic, and environmental factors that contribute to the development of our personality...
appear to be integral to the occurrence and persistence of depression, with
negative emotionalityIn psychology, affect is an emotion or subjectively experienced feeling. Affect theory is a branch of psychoanalysis that attempts to organize affects into discrete categories and connect each one with its typical response. So, for example, the affect of joy is observed through the reaction of...
as a common precursor. Although depressive episodes are strongly correlated with adverse events, a person's characteristic style of coping may be correlated with their resilience. Additionally, low
self-esteemSelf-esteem is a term used in psychology to reflect a person's overall evaluation or appraisal of his or her own worth.Self-esteem encompasses beliefs and emotions...
and self-defeating or distorted thinking are related to depression. Depression is less likely to occur, as well as quicker to remit, among those who are religious. It is not always clear which factors are causes or which are effects of depression; however, depressed persons who are able to make corrections in their thinking patterns often show improved mood and self-esteem.
American psychiatrist
Aaron T. BeckAaron Temkin Beck is an American psychiatrist and a professor emeritus in the department of psychiatry at the University of Pennsylvania. Beck's background was in psychoanalytic psychiatry...
developed what is now known as a cognitive model of depression in the early 1960s. He proposed that three concepts underlie depression: a
triadBeck's cognitive triad is a triad of types of negative thought present in depression proposed by Aaron Beck in 1976. The triad forms part of his Cognitive Theory Of Depression.The triad involves negative thoughts about:# The self,# The world/environment, and...
of negative thoughts composed of cognitive errors about oneself, one's world, and one's future; recurrent patterns of depressive thinking, or
schemas; and distorted information processing. From these principles, he developed the structured technique of cognitive behavioral therapy (CBT). According to American psychologist
Martin SeligmanMartin E. P. Seligman is an American psychologist and author of self-help books. A world-renowned authority on depression and abnormal psychology, he is known for his work on the theory of "learned helplessness", and according to The Daily Pennsylvanian is considered the father of positive...
, depression in humans is similar to
learned helplessnessLearned helplessness, as a technical term in animal psychology and related human psychology, means a condition of a human being or an animal in which it has learned to behave helplessly, even when the opportunity is restored for it to help itself by avoiding an unpleasant or harmful circumstance to...
in laboratory animals, who remain in unpleasant situations when they are able to escape, but do not because they initially learned they had no control.
Depressed individuals often blame themselves for negative events, and a 1993 study of hospitalized adolescents with self-reported depression shows that those who do this may not take credit for positive outcomes. This tendency is characteristic of a depressive
attributionalAttribution is a concept in social psychology referring to how individuals explain causes of events, other's behavior, and their own behavior.- Types of attribution :...
, or pessimistic
explanatory styleExplanatory style is a psychological attribute that indicates how people explain to themselves why they experience a particular event, either positive or negative. Psychologists have identified three components in explanatory style:...
. According to
Albert BanduraAlbert Bandura is a psychologist specializing in social cognitive theory and self-efficacy. He is most famous for his social learning theory.- Education and academic career :...
, a Canadian
social psychologistSocial psychology is the scientific study of how people's thoughts, feelings, and behaviors are influenced by the actual, imagined, or implied presence of others. By this definition, scientific refers to the empirical method of investigation. The terms thoughts, feelings, and behaviors include all...
associated with
social cognitive theorySocial Cognitive Theory, used in psychology, education, and communication, posits that portions of an individual's knowledge acquisition can be directly related to observing others within the context of social interactions, experiences, and outside media influences.-History:Social Cognitive Theory...
, depressed individuals have negative beliefs about themselves, based on experiences of failure, observing the failure of social models, a lack of social persuasion that they can succeed, and their own somatic and emotional states including tension and stress. These influences may result in a negative
self-conceptSelf-concept or self identity refers to the global understanding as well as the world around us and a sentient being has of him or herself. It presupposes but can be distinguished from self-consciousness, which is simply an awareness of one's self...
and a perceived lack of
self-efficacySelf-efficacy is the belief that one is capable of performing in a certain manner to attain certain goals. It is a belief that one has the capabilities to execute the courses of actions required to manage prospective situations...
; that is, they do not believe they can influence events or achieve personal goals.
An examination of depression in women indicates that vulnerability factors—such as early maternal loss, lack of a confiding relationship, responsibility for the care of several young children at home, and unemployment—can interact with life stressors to increase the risk of depression. For older adults, the factors are often health problems, changes in relationships with a spouse or adult children due to the transition to a
care-givingCaregiver may refer to:* Caregiver or carer - an unpaid person who cares for someone requiring support due to a disability, frailty, mental health problem, learning disability or old age* An assisted living situation* A nursing home...
or care-needing role, the death of a significant other, or a change in the availability or quality of social relationships with older friends because of their own health-related life changes.
The understanding of depression has also received contributions from the
psychoanalyticPsychoanalysis is a body of ideas developed by Austrian physician Sigmund Freud and continued by others. It is primarily devoted to the study of human psychological functioning and behavior, although it also can be applied to societies.
...
and
humanisticHumanistic psychology is a school of psychology that emerged in the 1950s in reaction to both behaviorism and psychoanalysis. It is explicitly concerned with the human dimension of psychology and the human context for the development of psychological theory....
branches of psychology. From the classical psychoanalytic perspective of Austrian psychiatrist
Sigmund FreudSigmund Freud , Sigismund Schlomo Freud , was an Austrian neurologist who founded the psychoanalytic school of psychology...
, depression, or
melancholiaMelancholia , also lugubriousness, from the Latin lugere, to mourn; moroseness, from the Latin morosus, self-willed, fastidious habit; wistfulness, from old English wist: intent, or saturnine, , in contemporary usage, is a mood disorder of non-specific depression,...
, may be related to interpersonal loss and early life experiences.
Existential therapistsExistential psychotherapy is partly based on the existential belief that human beings are alone in the world. This feeling of aloneness leads to feelings of meaninglessness which can be overcome only by creating one's own values and meanings...
have connected depression to the lack of both
meaningIn existentialism, meaning is understood as the worth of life. Meaning in existentialism is unlike typical conceptions of "the meaning of life", because it is descriptive. Due to the method of existentialism, prescriptive or declarative statements about meaning are unjustified. Meaning is only...
in the present and a vision of the future. The founder of humanistic psychology, American psychologist
Abraham MaslowAbraham Harold Maslow was an American psychologist. He is noted for his conceptualization of a "hierarchy of human needs", and is considered the founder of humanistic psychology.-Biography:...
, suggested that depression could arise when people are unable to attain their needs or to self-actualize, to realize their full potential.
Social
Poverty and social isolation are associated with increased risk of psychiatric problems in general.
Child abuseChild abuse is the physical and/or psychological/emotional mistreatment of children. In the United States, the Centers for Disease Control and Prevention define child maltreatment as any act or series of acts or commission or omission by a parent or other caregiver that results in harm, potential...
(
physicalPhysical abuse is abuse involving contact intended to cause feelings of intimidation, pain, injury, or other physical suffering or bodily harm.-Forms of physical abuse:*Striking*Punching*Pushing, pulling*Slapping*Whipping*Striking with an object...
,
emotionalPsychological abuse, also referred to as emotional abuse, is a form of abuse characterized by a person subjecting or exposing another to behavior that is psychologically harmful...
,
sexualSexual abuse, also referred to as molestation, is the forcing of undesired sexual behavior by one person upon another, when that force falls short of being a sexual assault. The offender is referred to as a sexual abuser or molester...
, or neglect) is also associated with increased risk of developing depressive disorders later in life. Disturbances in family functioning, such as parental (particularly maternal) depression, severe marital conflict or divorce, death of a parent, or other disturbances in parenting are additional risk factors. In adulthood, stressful life events are strongly associated with the onset of major depressive episodes. In this context, life events connected to social rejection appear to be particularly related to depression. Consistent with the hypothesis that people may become increasingly sensitized to life stress over successive recurrences of depression is evidence that a first episode is more likely to be immediately preceded by stressful life events than are recurrent ones.
The relationship between stressful life events and
social supportSocial support is the physical and emotional comfort given to us by our family, friends, co-workers and others. It is knowing that we are part of a community of people who love and care for us, and value and think well of us. Social support is a way of categorizing the rewards of communication in a...
has been a matter of some debate; the lack of social support may increase the likelihood that life stress will lead to depression, or the absence of social support may constitute a form of strain that leads to depression directly. There is evidence that neighborhood social disorder, for example, due to crime or illicit drugs, is a risk factor, and that a high neighborhood socioeconomic status, with better amenities, is a protective factor. Adverse conditions at work, particularly demanding jobs with little scope for decision-making, are associated with depression, although diversity and confounding factors make it difficult to confirm that the relationship is causal.
Evolutionary
From the standpoint of evolutionary theory, major depression is hypothesized, in some instances, to increase an individual's
ability to reproduceFitness is a central concept in evolutionary theory. It describes the capability of an individual of certain genotype to reproduce, and usually is equal to the proportion of the individual's genes in all the genes of the next generation...
.
Evolutionary approaches to depressionMajor depression is the leading cause of disability worldwide, and in 2000 was the fourth leading contributor to the global burden of disease ; it is also an important risk factor for suicide. It is understandable, then, that clinical depression is thought to be a pathology — a major dysfunction of...
and
evolutionary psychologyEvolutionary psychology attempts to explain psychological traits—such as memory, perception, or language—as adaptations, that is, as the functional products of natural selection or sexual selection. Adaptationist thinking about physiological mechanisms, such as the heart, lungs, and immune system,...
posit specific mechanisms by which depression may have been genetically incorporated into the human gene pool, accounting for the high
heritabilityIn genetics, Heritability is the proportion of phenotypic variation in a population that is attributable to genetic variation among individuals. Variation among individuals may be due to genetic and/or environmental factors...
and prevalence of depression by proposing that certain components of depression are adaptations, such as the behaviors relating to
attachmentAttachment theory is a psychological, evolutionary and ethological theory concerning relationships between humans. The most important tenet of attachment theory is that a young child needs to develop a relationship with at least one primary caregiver for normal social and emotional development...
and
social rankSocial classes are the hierarchical arrangements of people in society as economic or cultural groups. Class is an essential object of analysis for sociologists, political economists and social historians...
. Current behaviors can be explained as adaptations to regulate relationships or resources, although the result may be maladaptive in modern environments.
From a
counseling psychologyCounseling psychology is a psychological specialty that encompasses research and applied work in several broad domains: counseling process and outcome; supervision and training; career development and counseling; diversity and multiculturalism; and prevention and health...
viewpoint, the therapist may see depression, not as a biochemical illness or disorder, but as "a species-wide evolved suite of emotional programmes that are mostly activated by a perception, almost always over-negative, of a major decline in personal usefulness, that can sometimes be linked to guilt, shame or perceived rejection". This suite may have manifested in aging hunters in humans'
foragingForaging theory is a branch of behavioral ecology that studies the foraging behavior of animals in response to the environment in which the animal lives. Foraging theory considers the foraging behavior of animals in reference to the payoff that an animal obtains from different foraging options...
past, who were marginalized by their declining skills, and may continue to appear in
alienated membersIn sociology and critical social theory, alienation refers to an individual's estrangement from traditional community and others in general. It is considered by many that the atomism of modern society means that individuals have shallower relations with other people than they would normally...
of today's society. The feelings of uselessness generated by such marginalization could hypothetically prompt support from friends and kin. Additionally, in a manner analogous to that in which
physical painPhysical Pain is the unpleasant feeling common to a headache and a stubbed toe. It typically consists of negative affect and aversion, and has location, duration, intensity and a distinctive quality...
has evolved to hinder actions that may cause further injury, "
psychic miserySuffering, or pain, is an individual's basic affective experience of unpleasantness and aversion associated with harm or threat of harm. Suffering may be qualified as physical, or mental. It may come in all degrees of intensity, from mild to intolerable. Factors of duration and frequency of...
" may have evolved to prevent hasty and maladaptive reactions to distressing situations.
Drug and alcohol use
The DSM precludes a diagnosis of major depressive disorder for those presenting with "the direct physiological effects of a substance" because sedative hypnotic drugs such as
alcoholAn alcoholic beverage is a drink that contains ethanol . Alcoholic beverages are divided into three general classes: beers, wines, and spirits....
and benzodiazepines increase the risk of a syndrome that is similar to major depression. This increased risk may be due in part to the effects of drugs on
neurochemistryNeurochemistry is the specific study of neurochemicals, which include neurotransmitters and other molecules such as neuro-active drugs that influence neuron function. This principle closely examines the manner in which these neurochemicals influence the network of neural operation...
, such as decreased levels of serotonin and norepinephrine.
AlcoholismAlcoholism is a term with multiple and sometimes conflicting definitions. In common and historic usage, alcoholism is any condition that results in the continued consumption of alcoholic beverages, despite health problems and negative social consequences...
or excessive alcohol consumption significantly increases the risk of developing this syndrome. Chronic use of benzodiazepines, a class of medication that is commonly used to treat
insomniaInsomnia is a symptom of any of several sleep disorders, characterized by persistent difficulty falling asleep or staying asleep despite the opportunity. Insomnia is a symptom, not a stand-alone diagnosis or a disease. By definition, insomnia is "difficulty initiating or maintaining sleep, or both"...
,
anxietyAnxiety is a psychological and physiological state characterized by cognitive, somatic, emotional, and behavioral components. These components combine to create an unpleasant feeling that is typically associated with uneasiness, fear, or worry....
and muscular spasms, also increases the risk. Chronic, severe depression can develop as a result of chronic use of benzodiazepines or as part of a protracted withdrawal syndrome.
Clinical assessment
A diagnostic assessment may be conducted by a
general practitionerA general practitioner or GP is a medical practitioner who provides primary care and specializes in family medicine. A general practitioner treats acute and chronic illnesses and provides preventive care and health education for all ages and both sexes...
, or by a
psychiatristA psychiatrist is a physician who specializes in psychiatry and is certified in treating mental disorders. All psychiatrists are trained in diagnostic evaluation and in psychotherapy...
or
psychologistA psychologist is someone who studies the human mind and behavior. Research psychologists study human perception, cognition, attention, emotion, motivation, personality, behavior and interpersonal relationships...
, who
recordsA psychiatric history is the result of a medical process where a clinician working in the field of mental health systematically records the content of an interview with a patient...
the person's current circumstances, biographical history and current symptoms, and a family medical history to see if other family members have suffered from a mood disorder, and discusses the person's alcohol and drug use. The assessment also includes a mental state examination, which is an assessment of the person's current mood and thought content, in particular the presence of themes of hopelessness or pessimism,
self-harmSelf-injury , self-harm or deliberate self-harm is deliberate infliction of tissue damage or alteration to oneself without suicidal intent...
or suicide, and an absence of positive thoughts or plans. Specialist mental health services are rare in rural areas, and thus diagnosis and management is largely left to
primary carePrimary care is a term used for the activity of a health care provider who acts as a first point of consultation for all patients. Continuity of care is also a key characteristic of primary care....
clinicians. This issue is even more marked in developing countries. The score on a
rating scaleA rating scale is a set of categories designed to elicit information about a quantitative or a qualitative attribute. In the social sciences, common examples are the Likert scale and 1-10 rating scales in which a person selects the number which is considered to reflect the perceived quality of a...
alone is not sufficient to diagnose depression, but it provides an indication of the severity of symptoms for a time period, so a person who scores above a given cut-off point can be more thoroughly evaluated for a depressive disorder diagnosis. Several rating scales are used for this purpose.
ScreeningScreening, in medicine, is a strategy used in a population to detect a disease in individuals without signs or symptoms of that disease. Unlike most medicine, in screening, tests are performed on those without any clinical indication of disease....
programs have been advocated to improve detection of depression, but there is evidence that they do not improve detection rates, treatment, or outcome.
Primary care physicianA primary care physician, or PCP, is a physician/medical doctor who provides both the first contact for a person with an undiagnosed health concern as well as continuing care of varied medical conditions, not limited by cause, organ system, or diagnosis....
s and other non-psychiatrist physicians have difficulty diagnosing depression. Non-psychiatrists miss two-thirds of cases and unnecessarily treat other patients.
Before diagnosing a major depressive disorder, a doctor generally performs a medical examination and selected investigations to rule out other causes of symptoms. These include blood tests measuring
TSHThyroid-stimulating hormone is a peptide hormone synthesized and secreted by thyrotrope cells in the anterior pituitary gland which regulates the endocrine function of the thyroid gland....
and
thyroxineThyroxine, or 3,5,3',5'-tetraiodothyronine , a form of thyroid hormones is the major hormone secreted by the follicular cells of the thyroid gland. Thyroxine is synthesized via the iodination and covalent bonding of the phenyl portions of tyrosine residues found in an initial peptide,...
to exclude
hypothyroidismHypothyroidism is the disease state in humans and in animals caused by insufficient production of thyroid hormone by the thyroid gland. Cretinism is a form of hypothyroidism found in infants.-Causes:...
; basic electrolytes and serum
calciumCalcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft grey alkaline earth metal, and is the fifth most abundant element by mass in the Earth's crust...
to rule out a metabolic disturbance; and a
full blood countA complete blood count , also known as full blood count or full blood exam or blood panel, is a test requested by a doctor or other medical professional that gives information about the cells in a patient's blood...
including
ESRThe erythrocyte sedimentation rate , also called a sedimentation rate or Biernacki Reaction, is the rate at which red blood cells precipitate in a period of 1 hour...
to rule out a
systemic infectionSystemic infection is a generic term for infection caused by microorganisms in animals or plants, where the causal agent has spread actively or passively in the host's anatomy and is disseminated throughout several organs in different systems of the host...
or chronic disease. Adverse affective reactions to medications or alcohol misuse are often ruled out, as well.
TestosteroneTestosterone is a steroid hormone from the androgen group. In mammals, testosterone is primarily secreted in the testes of males and the ovaries of females, although small amounts are also secreted by the adrenal glands. It is the principal male sex hormone and an anabolic steroid.In men,...
levels may be evaluated to diagnose
hypogonadismHypogonadism is a medical term for a defect of the gonads that results in the underproduction of testosterone...
, a cause of depression in men.
Subjective cognitive complaints appear in older depressed people, but they can also be indicative of the onset of a
dementing disorderDementia is a serious cognitive disorder. It may be static, the result of a unique global brain injury or progressive, resulting in long-term decline in cognitive function due to damage or disease in the body beyond what might be expected from normal aging...
, such as
Alzheimer's diseaseAlzheimer's disease , also called Alzheimer disease, Senile Dementia of the Alzheimer Type or simply Alzheimer's, is the most common form of dementia. This incurable, degenerative, and terminal disease was first described by German psychiatrist and neuropathologist Alois Alzheimer in 1906 and was...
. (See also
Depression of Alzheimer diseaseDepression is one of the most common psychiatric symptoms in Alzheimer's disease, but it often appears in a different form than other depressive disorders. In 2002, a workgroup of the U.S...
.) Depression is also a common initial symptom of
dementiaDementia is a serious cognitive disorder. It may be static, the result of a unique global brain injury or progressive, resulting in long-term decline in cognitive function due to damage or disease in the body beyond what might be expected from normal aging...
.
Cognitive testingNeuropsychological assessment was traditionally carried out to assess the extent of impairment to a particular skill and to attempt to locate an area of the brain which may have been damaged after brain injury or neurological illness...
and brain imaging can help distinguish depression from dementia. A
CT scanComputed tomography is a medical imaging method employing tomography created by computer processing. Digital geometry processing is used to generate a three-dimensional image of the inside of an object from a large series of two-dimensional X-ray images taken around a single axis of rotation.CT...
can exclude brain pathology in those with psychotic, rapid-onset or otherwise unusual symptoms. No biological tests confirm major depression. Investigations are not generally repeated for a subsequent episode unless there is a medical indication.
DSM-IV-TR and ICD-10 criteria
The most widely used criteria for diagnosing depressive conditions are found in the
American Psychiatric AssociationThe American Psychiatric Association is the main professional organization of psychiatrists and trainee psychiatrists in the United States, and the most influential worldwide. Its some 38,000 members are mainly American but some are international...
's revised fourth edition of the
Diagnostic and Statistical Manual of Mental DisordersThe Diagnostic and Statistical Manual of Mental Disorders is published by the American Psychiatric Association and provides diagnostic criteria for mental disorders...
(DSM-IV-TR), and the
World Health OrganizationThe World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health...
's
International Statistical Classification of Diseases and Related Health ProblemsThe International Statistical Classification of Diseases and Related Health Problems provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings,...
(ICD-10) which uses the name
recurrent depressive disorder. The latter system is typically used in European countries, while the former is used in the US and many other non-European nations, and the authors of both have worked towards conforming one with the other.
Major depressive disorder is classified as a mood disorder in DSM-IV-TR. The diagnosis hinges on the presence of a single or recurrent
major depressive episodeA major depressive episode is the main symptom of major depressive disorder. The description has been formalised in psychiatric diagnostic criteria such as the DSM-IV and ICD-10, and is characterized by severe, highly persistent depression, and a loss of interest or pleasure in everyday activities,...
. Further qualifiers are used to classify both the episode itself and the course of the disorder. The category Depressive disorder not otherwise specified is diagnosed if the depressive episode's manifestation does not meet the criteria for a major depressive episode. The
ICD-10The International Statistical Classification of Diseases and Related Health Problems10th Revision is a coding of diseases and signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or diseases, as classified by the World Health Organization...
system does not use the term
Major depressive disorder, but lists very similar criteria for the diagnosis of a depressive episode (mild, moderate or severe); the term
recurrent may be added if there have been multiple episodes without mania.
Major depressive episode
A major depressive episode is characterized by the presence of a severely depressed mood that persists for at least two weeks. Episodes may be isolated or recurrent and are categorized as mild (few symptoms in excess of minimum criteria), moderate, or severe (marked impact on social or occupational functioning). An episode with psychotic features—commonly referred to as
psychotic depressionPsychotic major depression is a type of depression that can include symptoms and treatments that are different from those of non-psychotic major depressive disorder . PMD is estimated to affect about 0.4% of the population...
—is automatically rated as severe. If the patient has had an episode of
maniaMania is a severe medical condition characterized by extremely elevated mood, energy, unusual thought patterns and sometimes psychosis...
or
markedly elevated moodHypomania is a mood state characterized by persistent and pervasive elevated or irritable mood, and thoughts and behaviors that are consistent with such a mood state. An unequivocal change in functioning that is uncharacteristic when asymptomatic...
, a diagnosis of
bipolar disorderBipolar disorder, also known as manic depressive disorder, manic depression or bipolar affective disorder, is a serious mental disorder that describes a category of mood disorders defined by the presence of one or more episodes of abnormally elevated mood clinically referred to as mania or, if...
is made instead. Depression without mania is sometimes referred to as
unipolar because the mood remains at one emotional state or "pole".
DSM-IV-TR excludes cases where the symptoms are a result of bereavement, although it is possible for normal bereavement to evolve into a depressive episode if the mood persists and the characteristic features of a major depressive episode develop. The criteria have been criticized because they do not take into account any other aspects of the personal and social context in which depression can occur. In addition, some studies have found little empirical support for the DSM-IV cut-off criteria, indicating they are a diagnostic convention imposed on a continuum of depressive symptoms of varying severity and duration: excluded are a range of related diagnoses, including
dysthymiaDysthymic Disorder is a chronic mood disorder that falls within the depression spectrum. It is considered a chronic depression, but with less severity than major depressive disorder. This disorder tends to be a chronic, long-lasting illness....
which involves a chronic but milder mood disturbance,
Recurrent brief depressionRecurrent Brief Depression defines a mental disorder characterized by intermittent depressive episodes, in women not related to menstrual cycles, occurring at least once a month over at least one year or more fulfilling the diagnostic criteria for major depressive episodes except for duration...
which involves briefer depressive episodes,
minor depressive disorderMinor depressive Disorder, also known as Minor Depression, is a mood disorder that does not meet full criteria for Major depressive disorder but in which at least two depressive symptoms are present for two weeks. It is given in the DSM-IV-TR as an example of a Depressive Disorder Not Otherwise...
which involves only some of the symptoms of major depression, and
adjustment disorder with depressed moodIn psychology, adjustment disorder is a classification of mental disorder that is a psychological response from an identifiable stressor or group of stressors that causes significant emotional or behavioral symptoms that does not meet criteria for more specific disorders...
which involves low mood resulting from a psychological response to an identifiable event or stressor.
Subtypes
The DSM-IV-TR recognizes five further subtypes of MDD, called
specifiers, in addition to noting the length, severity and presence of psychotic features:
- Melancholic depression
Melancholic depression, or 'depression with melancholic features' is a subtype of major depression characterized by the inability to find pleasure in positive things combined with physical agitation, insomnia, or decreased appetite...
is characterized by a loss of pleasure in most or all activities, a failure of reactivity to pleasurable stimuli, a quality of depressed mood more pronounced than that of griefGrief is the multi-faceted response to loss, particularly to the loss of someone or something to which we have formed a bond of attachment. Although conventionally focused on the emotional response to loss, it also has physical, cognitive, behavioral, social, and philosophical dimensions...
or loss, a worsening of symptoms in the morning hours, early morning waking, psychomotor retardationPsychomotor retardation or "Psychomotor Slowing" comprises a slowing down of thought and a reduction of physical movements in an individual. This is most commonly seen in people with major depression , and indicates a certain degree of severity...
, excessive weight loss (not to be confused with anorexia nervosaAnorexia nervosa is a psychiatric illness that describes an eating disorder characterized by extremely low body weight and body image distortion with an obsessive fear of gaining weight...
), or excessive guilt.
- Atypical depression
Atypical depression is a subtype of dysthymia and major depression characterized by mood reactivity — being able to experience improved mood in response to positive events. In contrast, sufferers of "melancholic" depression generally cannot experience positive moods, even when good things happen...
is characterized by mood reactivity (paradoxical anhedonia) and positivity, significant weight gainWeight gain is an increase in body weight. This can be either an increase in muscle mass, fat deposits, or excess fluids such as water.-Description:In some cases, weight gain can also occur as a result of developing tumors or other abnormal growths...
or increased appetite (comfort eating), excessive sleep or sleepiness (hypersomniaHypersomnia is a disorder characterized by excessive amounts of sleepiness.From the website of the U.S. National Institute of Neurological Disorders and Stroke :-Causes:...
), a sensation of heaviness in limbs known as leaden paralysis, and significant social impairment as a consequence of hypersensitivity to perceived interpersonal rejectionSocial rejection occurs when an individual is deliberately excluded from a social relationship or social interaction. The topic includes both interpersonal rejection and romantic rejection. A person can be rejected on an individual basis or by an entire group of people...
.
- Catatonic depression
Catatonia is a syndrome of psychological and motorological disturbances. Karl Ludwig Kahlbaum first described it in 1874: Die Katatonie oder das Spannungirresein...
is a rare and severe form of major depression involving disturbances of motor behavior and other symptoms. Here the person is mute and almost stuporose, and either remains immobile or exhibits purposeless or even bizarre movements. Catatonic symptoms also occur in schizophreniaSchizophrenia , from the Greek roots skhizein and phrēn, phren- is a psychiatric diagnosis that describes a mental disorder characterized by abnormalities in the perception or expression of reality...
or in manic episodes, or may be caused by neuroleptic malignant syndromeNeuroleptic malignant syndrome is a neurological disorder most often caused by an adverse reaction to neuroleptic or antipsychotic drugs. It generally presents with muscle rigidity, fever, autonomic instability and cognitive changes such as delirium, and is associated with elevated creatine...
.
- Postpartum depression
Postpartum depression , also called postnatal depression, is a form of clinical depression which can affect women, and less frequently men, after childbirth. Studies report prevalence rates among women from 5% to 25%, but methodological differences among the studies make the actual prevalence rate...
(Mild mental and behavioral disorders associated with the puerperium, not elsewhere classified in ICD-10) refers to the intense, sustained and sometimes disabling depression experienced by women after giving birth. Postpartum depression, which has incidence rate of 10–15% among new mothers, typically sets in within three months of laborChildbirth is the culmination of a human pregnancy or gestation period with birth of one or more newborn infants from a woman's uterus...
, and lasts as long as three months.
- Seasonal affective disorder
Seasonal Affective Disorder , also known as winter depression or winter blues, is a mood disorder in which people who have normal mental health throughout most of the year experience depressive symptoms in the winter or, less frequently, in the summer, spring or fall, repeatedly, year after year...
(SAD) is a form of depression in which depressive episodes come on in the autumn or winter, and resolve in spring. The diagnosis is made if at least two episodes have occurred in colder months with none at other times, over a two-year period or longer.
Differential diagnoses
To confer major depressive disorder as the most likely diagnosis,
other potential diagnosesA differential diagnosis is a systematic method used to identify unknowns. This method, essentially a process of elimination, is used by taxonomists to identify living organisms, and by physicians or other clinicians to diagnose the specific disease in a patient.Not all medical diagnoses are...
must be considered, including dysthymia, adjustment disorder with depressed mood or bipolar disorder.
DysthymiaDysthymic Disorder is a chronic mood disorder that falls within the depression spectrum. It is considered a chronic depression, but with less severity than major depressive disorder. This disorder tends to be a chronic, long-lasting illness....
is a chronic, milder mood disturbance in which a person reports a low mood almost daily over a span of at least two years. The symptoms are not as severe as those for major depression, although people with dysthymia are vulnerable to secondary episodes of major depression (sometimes referred to as
double depression).
Adjustment disorder with depressed moodIn psychology, adjustment disorder is a classification of mental disorder that is a psychological response from an identifiable stressor or group of stressors that causes significant emotional or behavioral symptoms that does not meet criteria for more specific disorders...
is a mood disturbance appearing as a psychological response to an identifiable event or stressor, in which the resulting emotional or behavioral symptoms are significant but do not meet the criteria for a major depressive episode.
Bipolar disorderBipolar disorder, also known as manic depressive disorder, manic depression or bipolar affective disorder, is a serious mental disorder that describes a category of mood disorders defined by the presence of one or more episodes of abnormally elevated mood clinically referred to as mania or, if...
, previously known as
manic-depressive disorder, is a condition in which depressive phases alternate with periods of mania or
hypomaniaHypomania is a mood state characterized by persistent and pervasive elevated or irritable mood, and thoughts and behaviors that are consistent with such a mood state. An unequivocal change in functioning that is uncharacteristic when asymptomatic...
. Although depression is currently categorized as a separate disorder, there is ongoing debate because individuals diagnosed with major depression often experience some hypomanic symptoms, indicating a mood disorder continuum.
Prevention
A 2008 meta-analysis found that behavioral interventions, such as interpersonal therapy, are effective at preventing new onset depression. Because such interventions appear to be most effective when delivered to individuals or small groups, it has been suggested that they may be able to reach their large target audience most efficiently through the Internet. However, an earlier meta-analysis found preventive programs with a competence-enhancing component to be superior to behaviorally oriented programs overall, and found behavioral programs to be particularly unhelpful for older people, for whom social support programs were uniquely beneficial. Additionally, the programs that best prevented depression comprised more than eight sessions, each lasting between 60 and 90 minutes; were provided by a combination of lay and professional workers; had a high-quality research design; reported
attrition ratesChurn rate is also sometimes called attrition rate. It is one of two primary factors that determine the steady-state level of customers a business will support....
; and had a well-defined intervention. The "Coping with Depression" course (CWD) is claimed to be the most successful of psychoeducational interventions for the treatment and prevention of depression (both for its adaptability to various populations and its results), with a risk reduction of 38% in major depression and an efficacy as a treatment comparing favorably to other psychotherapies.
Management
The three most common treatments for depression are psychotherapy, medication, and electroconvulsive therapy. Psychotherapy is the treatment of choice for people under 18, while electroconvulsive therapy is only used as a last resort. Care is usually given on an outpatient basis, while treatment in an inpatient unit is considered if there is a significant risk to self or others. A significant number of recent studies have indicated that physical exercise has beneficial effects.
Treatment options are much more limited in developing countries, where access to mental health staff, medication, and psychotherapy is often difficult. Development of mental health services is minimal in many countries; depression is viewed as a phenomenon of the developed world despite evidence to the contrary, and not as an inherently life-threatening condition.
Psychotherapy
PsychotherapyPsychotherapy or personal counseling with a psychotherapist, is an intentional interpersonal relationship used by trained psychotherapists to aid a client or patient in problems of living.It aims to increase the individual's sense of their own well-being...
can be delivered, to individuals or groups, by mental health professionals, including psychotherapists, psychiatrists, psychologists, clinical
social workSocial Work is both a profession and social science. It involves the application of social theory and research methods to study and improve the lives of people, groups, and societies...
ers, counselors, and psychiatric nurses. With more complex and chronic forms of depression, a combination of medication and psychotherapy may be used. In people under 18, according to the
National Institute for Health and Clinical ExcellenceThe National Institute for Health and Clinical Excellence or NICE is a special health authority of the National Health Service in England and Wales...
, medication should only be offered in conjunction with a psychological therapy, such as CBT, interpersonal therapy, or family therapy. Psychotherapy has been shown to be effective in older people. Successful psychotherapy appears to reduce the recurrence of depression even after it has been terminated or replaced by occasional booster sessions.
The most studied form of psychotherapy for depression is CBT, thought to work by teaching clients to learn a set of useful cognitive and behavioral skills. Earlier research suggested that CBT was not as effective as antidepressant medication; however, research beginning in the mid-1990s suggested that CBT could perform as well or better than antidepressants in patients with moderate to severe depression. CBT may be effective in depressed adolescents, although its effects on severe episodes might not be definitively known. Combining fluoxetine with CBT appeared to bring no additional benefit, or, at the most, only marginal benefit. Several variables predict success for cognitive behavior therapy in adolescents: higher levels of rational thoughts, less hopelessness, fewer negative thoughts, and fewer cognitive distortions. CBT is particularly beneficial in preventing relapse.
Several variants of cognitive behavior therapy have been used in depressed patients, most notably
rational emotive behavior therapyRational emotive behavior therapy , previously called rational therapy and rational emotive therapy, is a comprehensive, active-directive, philosophically and empirically based psychotherapy which focuses on resolving emotional and behavioral problems and disturbances and enabling people to lead...
, and more recently
mindfulness-based cognitive therapyMindfulness-based cognitive therapy is a method of psychotherapy which blends features of cognitive therapy with mindfulness techniques. MBCT involves accepting thoughts and feelings without judgement rather than trying to push them out of consciousness, with a goal of correcting cognitive...
.
Interpersonal psychotherapyInterpersonal Psychotherapy is a time-limited psychotherapy that focuses on the interpersonal context and on building interpersonal skills. IPT is based on the belief that interpersonal factors may contribute heavily to psychological problems. It is commonly distinguished from other forms of...
focuses on the social and interpersonal triggers that may cause depression. The therapy takes a structured course with a set number of weekly sessions (often 12) that focus on relationships with others. Therapy can be used to foster
interpersonal skills"Interpersonal skills" refers to mental and communicative algorithms applied during social communications and interaction to reach certain effects or results. The term "interpersonal skills" is used often in business contexts to refer to the measure of a person's ability to operate within business...
that allow people to communicate more effectively and to reduce stress.
Psychoanalysis, a school of thought founded by Sigmund Freud that emphasizes the resolution of unconscious mental conflicts, is used by its practitioners to treat clients presenting with major depression. A more widely practiced, eclectic technique, called
psychodynamic psychotherapyPsychodynamic psychotherapy is a form of depth psychology, the primary focus of which is to reveal the unconscious content of a client's psyche in an effort to alleviate psychic tension. In this way, it is similar to psychoanalysis, but psychodynamic therapy tends to be briefer and less...
, is loosely based on psychoanalysis and has an additional social and interpersonal focus. In a meta-analysis of three controlled trials of Short Psychodynamic Supportive Psychotherapy, this modification was found to be as effective as medication for mild to moderate depression.
LogotherapyLogotherapy was developed by neurologist and psychiatrist Viktor Frankl. It is considered the "Third Viennese School of Psychotherapy" after Freud's psychoanalysis and Adler's individual psychology. It is a type of existentialist analysis that focuses on a will to meaning as opposed to Adler's...
, a form of existential psychotherapy developed by Austrian psychiatrist
Viktor FranklViktor Emil Frankl M.D., Ph.D. was an Austrian neurologist and psychiatrist as well as a Holocaust survivor. Frankl was the founder of logotherapy, which is a form of Existential Analysis, the "Third Viennese School of Psychotherapy"...
, addresses the filling of an
"existential vacuum"Emptiness as a human condition is a sense of generalised boredom, social alienation and apathy. Feelings of emptiness often accompany dysthymia, depression, loneliness, despair, or other mental/emotional disorders such as borderline personality disorder...
associated with feelings of futility and meaninglessness. This type of psychotherapy may be particularly useful for depressed adolescents.
Antidepressants
The effects of prescription antidepressants can be comparable to those of psychotherapy, although more patients cease medication than cease psychotherapy, most likely due to
side effectsAn adverse drug reaction is an expression that describes harm associated with the use of given medications at a normal dose. The meaning of this expression differs from the meaning of "side effect", as this last expression might also imply that the effects can be beneficial...
from the medication.
To find the most effective antidepressant medication with minimal side effects, the dosages can be adjusted, and if necessary, combinations of different classes of antidepressants can be tried. Response rates to the first antidepressant administered range from 50–75%, and it can take at least six to eight weeks from the start of medication to remission, when the patient is back to their normal self. Antidepressant medication treatment is usually continued for 16 to 20 weeks after remission, to minimize the chance of recurrence, and even up to 1 year of continuation is recommended. People with chronic depression may need to take medication indefinitely to avoid relapse.
Selective serotonin reuptake inhibitor Selective serotonin reuptake inhibitors or serotonin-specific reuptake inhibitor are a class of compounds typically used as antidepressants in the treatment of depression, anxiety disorders, and some personality disorders...
s (SSRIs), such as
sertralineSertraline hydrochloride is an antidepressant of the selective serotonin reuptake inhibitor class. It was introduced to the market by Pfizer in 1991. Sertraline is primarily used to treat major depression in adult outpatients as well as obsessive–compulsive, panic, and social anxiety disorders in...
,
escitalopramEscitalopram is an antidepressant of the selective serotonin reuptake inhibitor class. It is approved by the U.S...
,
fluoxetineFluoxetine is an antidepressant of the selective serotonin reuptake inhibitor class. Fluoxetine is approved for the treatment of major depression , obsessive-compulsive disorder , bulimia nervosa, anorexia nervosa, panic disorder and premenstrual dysphoric disorder...
,
paroxetineParoxetine is a selective serotonin reuptake inhibitor antidepressant. Marketing of the drug began in 1992 by the pharmaceutical company SmithKline Beecham, now GlaxoSmithKline...
, and
citalopramCitalopram is an antidepressant drug used to treat major depression associated with mood disorders. It is also used on occasion in the treatment of body dysmorphic disorder and anxiety....
are the primary medications prescribed owing to their effectiveness, relatively mild side effects, and because they are less toxic in overdose than other
antidepressantAn antidepressant is a psychiatric medication used to alleviate mood disorders, such as major depression and dysthymia. Drugs including the monoamine oxidase inhibitors , tricyclic antidepressants , tetracyclic antidepressants , selective serotonin reuptake inhibitors , and serotonin-norepinephrine...
s. Patients who do not respond to one SSRI can be switched to another, and this results in improvement in almost 50% of cases. Another option is to switch to the atypical antidepressant
bupropionBupropion is an atypical antidepressant that acts as a norepinephrine and dopamine reuptake inhibitor, and nicotinic antagonist...
.
VenlafaxineVenlafaxine is an arylalkanolamine SNRI, although some authors dispute the claim that it inhibits NE reuptake. First introduced by Wyeth in 1993, it is licensed for the amelioration of MDD, as an anxiolytic, & comorbid indications. In 2007, venlafaxine was the sixth most commonly prescribed...
, an antidepressant with a different mechanism of action, may be modestly more effective than SSRIs. However, venlafaxine is not recommended in the UK as a first-line treatment because of evidence suggesting its risks may outweigh benefits, and it is specifically discouraged in children and adolescents.
For adolescent depression, fluoxetine and escitalopram are the two recommended choices. Antidepressants have not been found to be beneficial in children. Any antidepressant can cause low serum sodium levels (also called
hyponatremiaHyponatremia is an electrolyte disturbance in which the sodium concentration in the plasma is lower than normal .Severe or rapidly progressing hyponatremia can result in swelling of the brain , and the symptoms of...
); nevertheless, it has been reported more often with SSRIs. It is not uncommon for SSRIs to cause or worsen insomnia; the sedating antidepressant
mirtazapineMirtazapine is a psychoactive drug of the benzazepine and tetracyclic antidepressant chemical classes which is used primarily as an antidepressant. It is sometimes also used as an anxiolytic, hypnotic, antiemetic, orexigenic, and antihistamine or antipruritic. Mirtazapine was introduced by...
can be used in such cases.
Tricyclic antidepressantTricyclic antidepressants are a class of psychoactive drugs used primarily as antidepressants, which were first discovered in the early 1950s, and subsequently introduced later in the decade...
s have more side effects than SSRIs and are usually reserved for the treatment of inpatients, for whom the tricyclic antidepressant
amitriptylineAmitriptyline is a psychoactive drug and pharmaceutical of the tricyclic antidepressant chemical class which is used primarily as an antidepressant and anxiolytic agent. It is the most widely prescribed TCA and perhaps also the most efficient against depressive symptoms.- Approved :Amitriptyline...
, in particular, appears to be more effective.
Monoamine oxidase inhibitorMonoamine oxidase inhibitors are a class of powerful antidepressant drugs prescribed for the treatment of depression. They are particularly effective in treating atypical depression, and have also shown efficacy in smoking cessation....
s, an older class of antidepressants, have been plagued by potentially life-threatening dietary and drug interactions. They are still used only rarely, although newer and better tolerated agents of this class have been developed.
The terms "refractory depression" and "treatment-resistant depression" are used to describe cases that do not respond to adequate courses of at least two antidepressants. In many major studies, only about 35% of patients respond well to medical treatment. It may be difficult for a doctor to decide when someone has treatment-resistant depression or whether the problem is due to coexisting disorders, which are common among patients with major depression.
Pharmacological augmentation
A doctor may add a medication with a different mode of action to bolster the effect of an antidepressant in cases of treatment resistance. Medication with
lithiumLithium pharmacology refers to use of the lithium ion, Li
+, as a drug. A number of chemical salts of lithium are used medically as a mood stabilizing drug, primarily in the treatment of bipolar disorder, where they have a role in the treatment of depression and particularly of mania,...
salts has been used to augment antidepressant therapy in those who have failed to respond to antidepressants alone. Furthermore, lithium dramatically decreases the suicide risk in recurrent depression. Addition of a thyroid hormone,
triiodothyronineTriiodothyronine, C
15H
12I
3NO
4, also known as T
3, is a thyroid hormone.Thyroid-stimulating hormone activates the production of thyroxine and T
3. This process is under regulation. In the thyroid, T
4 is converted to...
may work as well as lithium, even in patients with normal thyroid function. Addition of
atypical antipsychoticThe atypical antipsychotics are a group of antipsychotic drugs used to treat psychiatric conditions. Some atypical antipsychotics are FDA approved for use in the treatment of schizophrenia...
s when the patient has not responded to an antidepressant is also known to increase the effectiveness of antidepressant drugs, albeit offset by increased side effects.
Debated effectiveness
The effectiveness of antidepressants continues to be questioned. Their effectiveness has been shown to increase with the severity of the depression, and to reach clinical significance only in studies involving the most severely depressed, perhaps because the very severely depressed had a decreased response to the placebo effect rather than an increased response to the medication. An editorial in the
BMJ drew attention to bias in the publication of studies showing antidepressant efficacy compared to unpublished studies where the data did not support efficacy. Though these unpublished studies might have suffered methodological or other problems, the article called attention to the possibility that sponsor or journal bias might have inflated or created the apparent efficacy of antidepressants over placebo.
Black Box Warning
A
black box warningIn the United States, a black box warning is a type of warning that appears on the package insert for prescription drugs that may cause serious adverse effects...
was introduced in the United States in 2007 on SSRI and other antidepressant medications due to increased risk of suicidality in patients younger than 24 years old.
Electroconvulsive therapy
Electroconvulsive therapy (ECT) is a procedure whereby pulses of electricity are sent through the brain via two electrodes, usually one on each
templeTemple indicates the side of the head behind the eyes. The bone beneath is the temporal bone.-Anatomy:Cladists classify land vertebrates based on the presence of an upper hole, a lower hole, both, or neither in the cover of dermal bone which formerly covered the temporalis muscle. Those with no...
, to induce a
seizureAn epileptic seizure is a transient symptom of excessive or synchronous neuronal activity in the brain. It can manifest as an alteration in mental state, tonic or clonic movements, convulsions, and various other psychic symptoms...
while the patient is under a short
general anaestheticA general anaesthetic drug is an anaesthetic drug that brings about a reversible loss of consciousness...
. Hospital psychiatrists may recommend ECT for cases of severe major depression which have not responded to antidepressant medication or, less often, psychotherapy or supportive interventions. ECT can have a quicker effect than antidepressant therapy and thus may be the treatment of choice in emergencies such as catatonic depression where the patient has stopped eating and drinking, or where a patient is severely suicidal. ECT is probably more effective than pharmacotherapy for depression in the immediate short-term, although a landmark community-based study found much lower remission rates in routine practice. Used on its own the relapse rate within the first six months is very high; early studies put the rate at around 50%, while a more recent controlled trial found rates of 84% even with
placeboA placebo is a sham medical intervention. In one common placebo procedure, a patient is given an inert sugar pill, told that it may improve his/her condition, but not told that it is in fact inert...
s. The early relapse rate may be reduced by the use of psychiatric medications or further ECT (although the latter is not recommended by some authorities) but remains high. Common initial
adverse effectsIn medicine, an adverse effect is a harmful and undesired effect resulting from a medication or other intervention such as surgery. An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect, and may result from an unsuitable or incorrect dosage or...
from ECT include
shortShort-term memory refers to the capacity for holding a small amount of information in mind in an active, readily available state for a short period of time. The duration of short-term memory is believed to be in the order of seconds...
and
long-term memoryLong-term memory is memory that can last as little as a few days or as long as decades. It differs structurally and functionally from working memory or short-term memory, which ostensibly stores items for only around...
loss, disorientation and headache. Although objective psychological testing shows
memory disturbance after ECTAnterograde amnesia is a loss of the ability to create memories after the event that caused the amnesia occurs. Anterograde amnesia and retrograde amnesia, where memories created prior to the event are lost, can occur together in the same patient...
has mostly resolved by one month post treatment, ECT remains a controversial treatment, and debate on the extent of cognitive effects and safety continues.
Physical exercise
Physical exercisePhysical exercise is any bodily activity that enhances or maintains physical fitness and overall health. It is performed for many different reasons. These include strengthening muscles and the cardiovascular system, honing athletic skills, weight loss or maintenance and for enjoyment...
is recommended by
U.K. health authoritiesThe National Institute for Health and Clinical Excellence or NICE is a special health authority of the National Health Service in England and Wales...
, and a systematic review of 23 studies indicated a "large clinical effect". Among these, three studies employing
intention to treat analysisIn epidemiology, an intention to treat analysis is an analysis based on the initial treatment intent, not on the treatment eventually administered. ITT analysis is intended to avoid various misleading artifacts that can arise in intervention research...
and other
biasIn experimental science, experimenter's bias is bias towards a result expected by the human experimenter. David Sackett, in a useful review of biases in clinical studies, states that biases can occur in any one of seven stages of research:...
-reducing measures were inconclusive. Its benefits are most statistically significant in mild to moderate forms of depression and
anxietyAnxiety is a psychological and physiological state characterized by cognitive, somatic, emotional, and behavioral components. These components combine to create an unpleasant feeling that is typically associated with uneasiness, fear, or worry....
.
Over-the-counter compounds
St John's wortSt John's wort is the plant species Hypericum perforatum, also known as Tipton's Weed or Klamath weed, but, with qualifiers, is used to refer to any species of the genus Hypericum. Therefore, H. perforatum is sometimes called Common St John's wort to differentiate it...
is available
over-the-counterOver-the-counter drugs are medicines that may be sold to a customer without a prescription from a health care professional, as compared to prescription drugs, which may only be sold to customers possessing a valid prescription...
as a
herbal remedyHerbalism is a traditional medicinal or folk medicine practice based on the use of plants and plant extracts. Herbalism is also known as botanical medicine, medical herbalism, herbal medicine, herbology, and phytotherapy...
in some parts of the world; however, the evidence of its effectiveness for the treatment of major depression is varying and confusing. Its safety can be compromised by inconsistency in pharmaceutical quality and in the amounts of active ingredient in different preparations. Further, it interacts with numerous prescribed medicines including antidepressants, and it can reduce the effectiveness of
hormonal contraceptionHormonal contraception refers to birth control methods that act on the endocrine system. Almost all methods are composed of steroid hormones, although in India one selective estrogen receptor modulator is marketed as a contraceptive. The original hormonal method—the combined oral contraceptive...
.
The efficacy of omega-3 fatty acids for major depression is unclear, with controlled studies and meta-analyses supporting both positive and negative conclusions.
Reviews of short-term clinical trials of S-adenosylmethionine (SAMe) indicate that it may be effective in treating major depression in adults. A 2002 review reported that
tryptophanTryptophan is one of the 20 standard amino acids, as well as an essential amino acid in the human diet. It is encoded in the standard genetic code as the codon UGG...
and
5-hydroxytryptophan5-Hydroxytryptophan is a naturally occurring amino acid, a precursor to the neurotransmitter serotonin and an intermediate in tryptophan metabolism. It is marketed in the United States and other countries as a dietary supplement for use as an antidepressant, appetite suppressant, and sleep aid...
appear to be better than placebo, but found most of the evidence in their favor to be of poor quality and inconclusive.
Other somatic treatments
Repetitive transcranial magnetic stimulation (rTMS) applies powerful magnetic fields to the brain from outside the head. Multiple controlled studies support the use of this method in treatment-resistant depression; it has been approved for this indication in Europe, Canada, Australia, and the US. rTMS appeared similarly effective for both uncomplicated depression and depression resistant to medication; however, it was inferior to ECT in a side-by-side randomized trial.
Vagus nerve stimulationVagus nerve stimulation is an adjunctive treatment for certain types of intractable epilepsy and major depression. VNS uses an implanted stimulator that sends electric impulses to the left vagus nerve in the neck via a lead wire implanted under the skin.- Cyberonics VNS Device :VNS implantation...
was approved by the FDA in the United States in 2005 for use in treatment-resistant depression, although it failed to show short-term benefit in the only large double-blind trial when used as an adjunct on treatment-resistant patients; a 2008 systematic review concluded that despite the promising results reported mainly in open studies, further clinical trials are needed to confirm its efficacy in major depression.
Prognosis
Major depressive episodes often resolve over time whether or not they are treated. Outpatients on a waiting list show a 10–15% reduction in symptoms within a few months, with approximately 20% no longer meeting the full criteria for a depressive disorder. The
medianIn probability theory and statistics, a median is described as the number separating the higher half of a sample, a population, or a probability distribution, from the lower half. The median of a finite list of numbers can be found by arranging all the observations from lowest value to highest...
duration of an episode has been estimated to be 23 weeks, with the highest rate of recovery in the first three months.
Studies have shown that 80% of those suffering from their first major depressive episode will suffer from at least 1 more during their life, with a lifetime average of 4 episodes. Other general population studies indicate around half those who have an episode (whether treated or not) recover and remain well, while the other half will have at least one more, and around 15% of those experience chronic recurrence. Studies recruiting from selective inpatient sources suggest lower recovery and higher chronicity, while studies of mostly outpatients show that nearly all recover, with a median episode duration of 11 months. Around 90% of those with severe or psychotic depression, most of whom also meet criteria for other mental disorders, experience recurrence.
Recurrence is more likely if symptoms have not fully resolved with treatment. Current guidelines recommend continuing antidepressants for four to six months after remission to prevent relapse. Evidence from many
randomized controlled trialA randomized controlled trial is a type of scientific experiment most commonly used in testing the efficacy or effectiveness of healthcare services or health technologies . RCTs are also employed in other research areas, such as judicial, educational, and social research...
s indicates continuing antidepressant medications after recovery can reduce the chance of relapse by 70% (41% on placebo vs. 18% on antidepressant). The preventive effect probably lasts for at least the first 36 months of use.
Depressed individuals have a shorter
life expectancyLife expectancy is the expected number of years of life remaining at a given age. It is denoted by e
x, which means the average number of subsequent years of life for someone now aged x, according to a particular mortality experience...
than those without depression, in part because depressed patients are at risk of dying by suicide. However, they also have a higher
rate of dyingMortality rate is a measure of the number of deaths in some population, scaled to the size of that population, per unit time. Mortality rate is typically expressed in units of deaths per 1000 individuals per year; thus, a mortality rate of 9.5 in a population of 100,000 would mean 950 deaths per...
from other causes, being more susceptible to medical conditions such as heart disease. Up to 60% of people who commit suicide have a mood disorder such as major depression, and the risk is especially high if a person has a marked sense of hopelessness or has both depression and
borderline personality disorderBorderline personality disorder is a psychiatric diagnosis in the Diagnostic and Statistical Manual of Mental Disorders that describes a prolonged disturbance of personality function characterized by depth and variability of moods...
. The lifetime risk of suicide associated with a diagnosis of major depression in the US is estimated at 3.4%, which averages two highly disparate figures of almost 7% for men and 1% for women (although suicide attempts are more frequent in women). The estimate is substantially lower than a previously accepted figure of 15% which had been derived from older studies of hospitalized patients.
Epidemiology
Depression is a major cause of morbidity worldwide. Lifetime prevalence varies widely, from 3% in Japan to 17% in the US. In most countries the number of people who would suffer from depression during their lives falls within an 8–12% range. In North America the probability of having a major depressive episode within a year-long period is 3–5% for males and 8–10% for females. Population studies have consistently shown major depression to be about twice as common in women as in men, although it is unclear why this is so, and whether factors unaccounted for are contributing to this. The relative increase in occurrence is related to pubertal development rather than chronological age, reaches adult ratios between the ages of 15 and 18, and appears associated with psychosocial more than hormonal factors.
People are most likely to suffer their first depressive episode between the ages of 30 and 40, and there is a second, smaller peak of incidence between ages 50 and 60. The risk of major depression is increased with neurological conditions such as
strokeA stroke is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by thrombosis or embolism or due to a hemorrhage...
,
Parkinson's diseaseParkinson's disease is a degenerative disorder of the central nervous system that often impairs the sufferer's motor skills, speech, and other functions....
, or
multiple sclerosisMultiple sclerosis is an idiopathic disease of suspected autoimmune cause, in which the body's immune response attacks a person's central nervous system , leading to demyelination. Disease onset usually occurs in young adults, and it is more common in females...
and during the first year after childbirth. It is also more common after cardiovascular illnesses, and is related more to a poor outcome than to a better one. Studies conflict on the prevalence of depression in the elderly, but most data suggest there is a reduction in this age group.
Depression is often associated with unemployment and poverty. Major depression is currently the leading cause of
disease burdenDisease burden is the impact of a health problem in an area measured by financial cost, mortality, morbidity, or other indicators. It is often quantified in terms of quality-adjusted life years or disability-adjusted life years , which combine the burden due to both death and morbidity into one...
in North America and other high-income countries, and the fourth-leading cause worldwide. In the year 2030, it is predicted to be the second-leading cause of disease burden worldwide after
HIVHuman immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which the immune system begins to fail, leading to life-threatening opportunistic infections. Infection with HIV occurs by the transfer of blood, semen, vaginal fluid,...
, according to the World Health Organization. Delay or failure in seeking treatment after relapse, and the failure of health professionals to provide treatment, are two barriers to reducing disability.
Comorbidity
Major depression frequently
co-occursIn medicine, comorbidity is either:* The presence of one or more disorders in addition to a primary disease or disorder; or* The effect of such additional disorders or diseases....
with other psychiatric problems. The 1990–92
National Comorbidity Survey (US) reports that 51% of those with major depression also suffer from lifetime
anxietyAnxiety is a psychological and physiological state characterized by cognitive, somatic, emotional, and behavioral components. These components combine to create an unpleasant feeling that is typically associated with uneasiness, fear, or worry....
. Anxiety symptoms can have a major impact on the course of a depressive illness, with delayed recovery, increased risk of relapse, greater disability and increased suicide attempts. American neuroendocrinologist
Robert SapolskyRobert Maurice Sapolsky is an American biologist and author. He is currently professor of Biological Sciences, and Professor of Neurology and Neurological Sciences, and by courtesy, Neurosurgery, at Stanford University. In addition, he is a research associate at the National Museums of Kenya...
similarly argues that the relationship between stress, anxiety, and depression could be measured and demonstrated biologically. There are increased rates of alcohol and drug abuse and particularly dependence, and around a third of individuals diagnosed with
ADHDAttention-deficit hyperactivity disorder is a neurobehavioral developmental disorder. ADHD is primarily characterized by "the co-existence of attentional problems and hyperactivity, with each behavior occurring infrequently alone." While symptoms may appear to be innocent and merely annoying...
develop comorbid depression.
Post-traumatic stress disorderPosttraumatic stress disorder is an anxiety disorder that can develop after exposure to one or more traumatic events that threatened or caused great physical harm....
and depression often co-occur.
Depression and
painPhysical Pain is the unpleasant feeling common to a headache and a stubbed toe. It typically consists of negative affect and aversion, and has location, duration, intensity and a distinctive quality...
often co-occur. One or more pain symptoms is present in 65% of depressed patients, and anywhere from five to 85% of patients with pain will be suffering from depression, depending on the setting; there is a lower prevalence in general practice, and higher in specialty clinics. The diagnosis of depression is often delayed or missed, and the outcome worsens.
Depression is also associated with a 1.5- to 2-fold increased risk of
cardiovascular diseaseCardiovascular disease or cardiovascular diseases is the class of diseases that involve the heart or blood vessels ....
, independent of other known risk factors, and is itself linked directly or indirectly to risk factors such as smoking and obesity. People with major depression are less likely to follow medical recommendations for treating cardiovascular disorders, which further increases their risk. In addition, cardiologists may not recognize underlying depression that complicates a cardiovascular problem under their care.
History
The Ancient Greek physician
HippocratesHippocrates of Cos or Hippokrates of Kos - Greek: ; Hippokrátēs was an ancient Greek physician of the Age of Pericles, and was considered one of the most outstanding figures in the history of medicine...
described a syndrome of melancholia as a distinct disease with particular mental and physical symptoms; he characterized all "fears and despondencies, if they last a long time" as being symptomatic of the ailment. It was a similar but far broader concept than today's depression; prominence was given to a clustering of the symptoms of sadness, dejection, and despondency, and often fear, anger, delusions and obsessions were included.
The term
depression itself was derived from the Latin verb
deprimere, "to press down". From the 14th century, "to depress" meant to subjugate or to bring down in spirits. It was used in 1665 in English author
Richard Baker'sSir Richard Baker was the English author of the Chronicle of the Kings of England and other works.-Life:He was probably born at Sissinghurst in Kent, the grandson of Sir John Baker, the first Chancellor of the Exchequer. He entered Hart Hall, Oxford, as a commoner in 1584...
Chronicle to refer to someone having "a great depression of spirit", and by English author
Samuel JohnsonSamuel Johnson , often referred to as Dr. Johnson, was an English author who made lasting contributions to English literature as a poet, essayist, moralist, novelist, literary critic, biographer, editor and lexicographer. Johnson was a devout Anglican and political conservative, and has been...
in a similar sense in 1753. The term also came in to use in
physiologyDepression in physiology and medicine refers to a lowering, in particular a reduction in a particular biological variable or the function of an organ...
and
economicsIn economics, a depression is a sustained, long-term downturn in economic activity in one or more economies. It is a more severe downturn than a recession, which is seen as part of a normal business cycle....
. An early usage referring to a psychiatric symptom was by French psychiatrist
Louis DelasiauveLouis Jean Francois Delasiauve was a French psychiatrist who was a native of Garennes-sur-Eure. In 1830 he earned his doctorate in Paris, and for the next eight years practiced medicine in Ivry. Afterwards he worked at the Bicêtre Hospital, and later became a director at the Salpêtrière, where he...
in 1856, and by the 1860s it was appearing in medical dictionaries to refer to a physiological and metaphorical lowering of emotional function. Since
AristotleAristotle was a Greek philosopher, a student of Plato and teacher of Alexander the Great. He wrote on many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, politics, government, ethics, biology, and zoology.Together with Plato and Socrates , Aristotle is one of...
, melancholia had been associated with men of learning and intellectual brilliance, a hazard of contemplation and creativity. The newer concept abandoned these associations and through the 19th century, became more associated with women.
Although
melancholia remained the dominant diagnostic term,
depression gained increasing currency in medical treatises and was a synonym by the end of the century; German psychiatrist
Emil KraepelinEmil Kraepelin was a German psychiatrist. The Encyclopedia of Psychology by H. J. Eysenck identifies him as the founder of contemporary scientific psychiatry, as well as of psychopharmacology and psychiatric genetics. Kraepelin believed the chief origin of psychiatric disease to be biological...
may have been the first to use it as the overarching term, referring to different kinds of melancholia as
depressive states.
Sigmund Freud likened the state of melancholia to mourning in his 1917 paper
Mourning and Melancholia. He theorized that
objectiveIn philosophy, an object is a thing, an entity, or a being. This may be taken in several senses. In its weakest sense, the word "object" is the most all-purpose of nouns, and can replace a noun in any sentence at all...
loss, such as the loss of a valued relationship through death or a romantic break-up, results in
subjectiveIn philosophy, a subject is a being which has subjective experiences, subjective consciousness or a relationship with another entity . A subject is an observer and an object is a thing observed...
loss as well; the depressed individual has identified with the object of affection through an
unconsciousThe unconscious mind is a term invented by the 18th century German romantic philosopher Ser Christopher Riegel and later introduced into English by the poet and essayist Samuel Taylor Coleridge...
,
narcissisticSee also narcissistic personality disorder and malignant narcissism.The term narcissism refers to the personality trait of self-esteem, which includes the set of character traits concerned with self-image or ego. The terms narcissism, narcissistic, and narcissist are often used as pejoratives,...
process called the
libidinal cathexisIn psychodynamics, cathexis is defined as the process of investment of mental or emotional energy in a person, object, or idea. The Greek term 'cathexis' was chosen by James Strachey to render the German term 'Besetzung' in his translations of Sigmund Freud's complete works. In psychoanalysis,...
of the
egoego are the initials of an abstract poet named ernesto garcia orduna ...Ego is a Latin word meaning "I", cognate with the Greek "Εγώ " meaning "I" and may refer to:...
. Such loss results in severe melancholic symptoms more profound than mourning; not only is the outside world viewed negatively, but the ego itself is compromised. The patient's decline of self-perception is revealed in his belief of his own blame, inferiority, and unworthiness. He also emphasized early life experiences as a predisposing factor. Meyer put forward a mixed social and biological framework emphasizing
reactions in the context of an individual's life, and argued that the term
depression should be used instead of
melancholia. The first version of the DSM (DSM-I, 1952) contained
depressive reaction and the DSM-II (1968)
depressive neurosis, defined as an excessive reaction to internal conflict or an identifiable event, and also included a depressive type of manic-depressive psychosis within Major affective disorders.
In the mid-20th century, researchers theorized that depression was caused by a chemical imbalance in neurotransmitters in the brain, a theory based on observations made in the 1950s of the effects of
reserpineReserpine is an indole alkaloid antipsychotic and antihypertensive drug that has been used for the control of high blood pressure and for the relief of psychotic behaviors, although because of the development of better drugs for these purposes and because of its numerous side-effects, it is rarely...
and
isoniazidIsoniazid is an organic compound that is the first-line antituberculosis medication in prevention and treatment. First discovered in 1912 as an inhibitor of the MAO enzyme, it was first used as an antidepressant, but discontinued due to side effects...
in altering monoamine neurotransmitter levels and affecting depressive symptoms.
The term
Major depressive disorder was introduced by a group of US clinicians in the mid-1970s as part of proposals for diagnostic criteria based on patterns of symptoms (called the "Research Diagnostic Criteria", building on earlier Feighner Criteria), and was incorporated in to the DSM-III in 1980. To maintain consistency the ICD-10 used the same criteria, with only minor alterations, but using the DSM diagnostic threshold to mark a
mild depressive episode, adding higher threshold categories for moderate and severe episodes. The ancient idea of
melancholia still survives in the notion of a melancholic subtype.
The new definitions of depression were widely accepted, albeit with some conflicting findings and views. There have been some continued empirically based arguments for a return to the diagnosis of melancholia. There has been some criticism of the expansion of coverage of the diagnosis, related to the development and promotion of antidepressants and the biological model since the late 1950s.
Sociocultural aspects
Even today, people's conceptualizations of depression vary widely, both within and among cultures. "Because of the lack of scientific certainty," one commentator has observed, "the debate over depression turns on questions of language. What we call it—'disease,' 'disorder,' 'state of mind'—affects how we view, diagnose, and treat it." There are cultural differences in the extent to which serious depression is considered an illness requiring personal professional treatment, or is an indicator of something else, such as the need to address social or moral problems, the result of biological imbalances, or a reflection of individual differences in the understanding of distress that may reinforce feelings of powerlessness, and emotional struggle.
The diagnosis is less common in some countries, such as
ChinaChina is a cultural region, an ancient civilization, and, depending on perspective, a national or multinational entity extending over a large area in East Asia....
. It has been argued that the Chinese traditionally deny or
somatizeSomatization is currently defined as "a tendency to experience and communicate somatic distress in response to psychosocial stress and to seek medical help for it".This can be, but not always, related to a psychological condition such as:...
emotional depression (although since the early 1980s the Chinese denial of depression may have modified drastically). Alternatively, it may be that Western cultures reframe and elevate some expressions of human distress to disorder status. Australian professor
Gordon ParkerGordon Parker is a professor of Psychiatry at the University of New South Wales, specializing in research in mental health.Gordon has an MB BS Syd and a MD 1978, PhD 1983, DSc 1997 from UNSW and is a FRANZCP...
and others have argued that the Western concept of depression "medicalizes" sadness or misery. Similarly, Hungarian-American psychiatrist
Thomas SzaszThomas Stephen Szasz ; born April 15, 1920 in Budapest, Hungary) is a psychiatrist and academic. Since 1990 he has been Professor Emeritus of Psychiatry at the State University of New York Health Science Center in Syracuse, New York...
and others argue that depression is a metaphorical illness that is inappropriately regarded as an actual disease. There has also been concern that the DSM, as well as the field of
descriptive psychiatryDescriptive psychiatry is based on the study of observable symptoms and behavioral phenomena rather than underlying psychodynamic processes. In descriptive psychiatry, the clinical psychiatrist focuses on empirically observable behaviors and conditions, such as words spoken or actions taken.Modern...
that employs it, tends to
reifyReification is a fallacy of ambiguity, when an abstraction is treated as if it were a concrete, real event, or physical entity...
abstract phenomena such as depression, which may in fact be
social constructsSocial constructionism and social constructivism are sociological theories of knowledge that consider how social phenomena develop in social contexts...
. American
archetypal psychologistArchetypal Psychology is a vein of inquiry into the psyche inaugurated in the early 1900s by Dr. Carl Gustav Jung. Dr. Jung and his followers, as well as Mircea Eliade, imagined the psychology of the archetypes from studying anthropology and archeology reports of their times, and weaving it into...
James HillmanJames Hillman is an American psychologist. He studied at the C.G. Jung Institute in Zurich, developed archetypal psychology and is now retired as a private practitioner.-Biography:...
writes that depression can be healthy for the
soulThe soul, in many religions, spiritual traditions, and philosophies, is the spiritual and eternal part of a living being, commonly held to be separable in existence from the body; distinct from the physical part. It is typically thought to consist of ones consciousness and personality, and can be...
, insofar as "it brings refuge, limitation, focus, gravity, weight, and humble powerlessness." Hillman argues that therapeutic attempts to eliminate depression echo the Christian theme of
resurrectionThe resurrection of dead humans is a central doctrine of Judaism, Christianity, and Islam. It may refer either to the resurrection of particular individuals, or a general resurrection of humanity....
, but have the unfortunate effect of demonizing a soulful state of being.
Historical figures were often reluctant to discuss or seek treatment for depression due to
social stigmaSocial stigma is severe social disapproval of personal characteristics or beliefs that are perceived to be against cultural norms. Stigma is often based on ignorance, irrational or unfounded fears, mass hysteria, lack of education, or a lack of information pertaining to a particular person or group...
about the condition, or due to ignorance of diagnosis or treatments. Nevertheless, analysis or interpretation of letters, journals, artwork, writings or statements of family and friends of some historical personalities has led to the presumption that they may have had some form of depression. People who may have had depression include English author
Mary ShelleyMary Shelley was a British novelist, short story writer, dramatist, essayist, biographer, and travel writer, best known for her Gothic novel Frankenstein: or, The Modern Prometheus . She also edited and promoted the works of her husband, the Romantic poet and philosopher Percy Bysshe Shelley...
, American-British writer
Henry JamesHenry James, O.M. was an American author who expatriated to England, and who acquired British nationality near the end of his life. One of the key figures of 19th century literary realism, James was born in the United States, the son of theologian Henry James, Sr., and brother of the philosopher...
, and American president
Abraham LincolnAbraham Lincoln was the 16th President of the United States, serving from March 1861 until his assassination in April 1865. He successfully led his country through its greatest internal crisis, the American Civil War, preserving the Union and ending slavery...
. Some well-known contemporary people with possible depression include Canadian songwriter
Leonard CohenLeonard Norman Cohen, CC, GOQ is a Canadian singer-songwriter, musician, poet and novelist. Cohen published his first book of poetry in Montreal in 1956 and his first novel in 1963. His work often deals with the exploration of religion, isolation, sexuality and complex interpersonal relationships...
and American playwright and novelist
Tennessee WilliamsTennessee Williams , né Thomas Lanier Williams, was an American playwright who received many of the top theatrical awards for his works of drama...
. Some pioneering psychologists, such as Americans
William JamesWilliam James was a pioneering American psychologist and philosopher trained as a medical doctor. He wrote influential books on the young science of psychology, educational psychology, psychology of religious experience and mysticism, and the philosophy of pragmatism...
and
John B. WatsonJohn Broadus Watson is an American psychologist who established the psychological school of behaviorism, after doing research on animal behavior. He also conducted the controversial "Little Albert" experiment...
, dealt with their own depression.
There has been a continuing discussion of whether neurological disorders and mood disorders may be linked to
creativityCreativity is a mental and social process involving the generation of new ideas or concepts, or new associations of the creative mind between existing ideas or concepts. Creativity is fueled by the process of either conscious or unconscious insight...
, a discussion that goes back to Aristotelian times. British literature gives many examples of reflections on depression. English philosopher
John Stuart MillJohn Stuart Mill , English philosopher, political theorist, political economist, civil servant and Member of Parliament, was an influential liberal thinker of the 19th century whose works on liberty justified freedom of the individual in opposition to unlimited state control...
experienced a several-months-long period of what he called "a dull state of nerves", when one is "unsusceptible to enjoyment or pleasurable excitement; one of those moods when what is pleasure at other times, becomes insipid or indifferent". He quoted English poet
Samuel Taylor ColeridgeSamuel Taylor Coleridge was an English poet, Romantic, literary critic and philosopher who, with his friend William Wordsworth, was one of the founders of the Romantic Movement in England and one of the Lake Poets...
's "Dejection" as a perfect description of his case: "A grief without a pang, void, dark and drear, / A drowsy, stifled, unimpassioned grief, / Which finds no natural outlet or relief / In word, or sigh, or tear." English writer Samuel Johnson used the term "the black dog" in the 1780s to describe his own depression, and it was subsequently popularized by depression sufferer former British Prime Minister Sir
Winston ChurchillSir Winston Leonard Spencer Churchill KG, OM, CH, TD, FRS, PC was a British politician known chiefly for his leadership of the United Kingdom during World War II. He served as Prime Minister from 1940 to 1945 and again from 1951 to 1955. A noted statesman and orator, Churchill was also an officer...
.
Social stigma of major depression is widespread, and contact with mental health services reduces this only slightly. Public opinions on treatment differ markedly to those of health professionals; alternative treatments are held to be more helpful than pharmacological ones, which are viewed poorly. In the UK, the
Royal College of PsychiatristsThe Royal College of Psychiatrists is the main professional organisation of psychiatrists in the United Kingdom, but now not the Republic of Ireland, responsible for representing psychiatrists, psychiatric research and providing high quality public information about mental health problems...
and the
Royal College of General PractitionersThe Royal College of General Practitioners is the professional body for general practitioners in the United Kingdom. The RCGP represents and supports GPs on key issues including licensing, education, training, research and clinical standards. It is the largest of the medical royal colleges, with...
conducted a joint Five-year Defeat Depression campaign to educate and reduce stigma from 1992 to 1996; a MORI study conducted afterwards showed a small positive change in public attitudes to depression and treatment.
External links
- DSM-IV diagnostic criteria for major depressive disorder – DSM-IV-TR
The Diagnostic and Statistical Manual of Mental Disorders is published by the American Psychiatric Association and provides diagnostic criteria for mental disorders...
text from behavenet.com
- National Alliance on Mental Illness – National Alliance on Mental Illness
The National Alliance on Mental Illness was founded in 1979 as the National Alliance for the Mentally Ill. NAMI is a nation-wide American advocacy group, representing families and people affected by mental illness as a non-profit grass roots organization and has affiliates in every American state...
- Depression, out of the shadows – Public Broadcasting Service
The Public Broadcasting Service is an American non-profit public broadcasting television service with 354 member TV stations in the United States which hold collective ownership. However, its operations are largely funded by the Corporation for Public Broadcasting...
, a USA television program broadcast in May 2008
- Psycheducation.org - Information about depression and mood swings, collected by Dr. Phelps.
- BipolArt Art and Bipolar Disorder