Folie à deux
Encyclopedia
Folie à deux (or shared psychosis) is a psychiatric
syndrome in which symptoms of a delusion
al belief are transmitted from one individual to another. The same syndrome shared by more than two people may be called folie à trois, folie à quatre, folie en famille or even folie à plusieurs ("madness of many"). Recent psychiatric classifications refer to the syndrome as shared psychotic disorder (DSM-IV
) (297.3) and induced delusional disorder (F.24) in the ICD-10, although the research literature largely uses the original name. The disorder was first conceptualized in 19th century French psychiatry.
Margaret and her husband Michael, both aged 34 years, were discovered to be suffering from folie à deux when they were both found to be sharing similar persecutory delusions. They believed that certain persons were entering their house, spreading dust and fluff and "wearing down their shoes". Both had, in addition, other symptoms supporting a diagnosis of emotional contagion
, which could be made independently in either case.
This syndrome is most commonly diagnosed when the two or more individuals concerned live in proximity and may be socially or physically isolated and have little interaction with other people.
Various sub-classifications of folie à deux have been proposed to describe how the delusional belief comes to be held by more than one person.
Folie à deux and its more populous cousins are in many ways a psychiatric curiosity. The current Diagnostic and Statistical Manual of Mental Disorders
states that a person cannot be diagnosed as being delusional if the belief in question is one "ordinarily accepted by other members of the person's culture or subculture" (see entry for delusion
). It is not clear at what point a belief considered to be delusional escapes from the folie à... diagnostic category and becomes legitimate because of the number of people holding it. When a large number of people may come to believe obviously false and potentially distressing things based purely on hearsay, these beliefs are not considered to be clinical delusions by the psychiatric profession and are labelled instead as mass hysteria.
In a well-publicised case in the United Kingdom
, the condition was one of two possible diagnoses of a Swedish woman, Sabina Eriksson
, who stabbed a man to death after he took her into his home, offering food and shelter. Eriksson had just been released from police custody following an incident on a motorway which grabbed news headlines. Caught on camera by a police documentary filmmaker, her twin sister ran into the path of an oncoming articulated lorry, sustaining severe injuries. Eriksson then immediately duplicated her twin's actions by stepping into the path of an oncoming car; she survived the impact. The defence counsel in the ultimate murder trial claimed that Eriksson was a 'secondary' sufferer of folie à deux, influenced by the presence or perceived presence of her twin sister — the 'primary'.
Psychiatry
Psychiatry is the medical specialty devoted to the study and treatment of mental disorders. These mental disorders include various affective, behavioural, cognitive and perceptual abnormalities...
syndrome in which symptoms of a delusion
Delusion
A delusion is a false belief held with absolute conviction despite superior evidence. Unlike hallucinations, delusions are always pathological...
al belief are transmitted from one individual to another. The same syndrome shared by more than two people may be called folie à trois, folie à quatre, folie en famille or even folie à plusieurs ("madness of many"). Recent psychiatric classifications refer to the syndrome as shared psychotic disorder (DSM-IV
Diagnostic and Statistical Manual of Mental Disorders
The Diagnostic and Statistical Manual of Mental Disorders is published by the American Psychiatric Association and provides a common language and standard criteria for the classification of mental disorders...
) (297.3) and induced delusional disorder (F.24) in the ICD-10, although the research literature largely uses the original name. The disorder was first conceptualized in 19th century French psychiatry.
Presentation
This case study is taken from Enoch and Ball's 'Uncommon Psychiatric Syndromes' (2001, p181):Margaret and her husband Michael, both aged 34 years, were discovered to be suffering from folie à deux when they were both found to be sharing similar persecutory delusions. They believed that certain persons were entering their house, spreading dust and fluff and "wearing down their shoes". Both had, in addition, other symptoms supporting a diagnosis of emotional contagion
Emotional contagion
Emotional contagion is the tendency to catch and feel emotions that are similar to and influenced by those of others. One view developed by John Cacioppo of the underlying mechanism is that it represents a tendency to automatically mimic and synchronize facial expressions, vocalizations, postures,...
, which could be made independently in either case.
This syndrome is most commonly diagnosed when the two or more individuals concerned live in proximity and may be socially or physically isolated and have little interaction with other people.
Various sub-classifications of folie à deux have been proposed to describe how the delusional belief comes to be held by more than one person.
- Folie imposée is where a dominant person (known as the 'primary', 'inducer' or 'principal') initially forms a delusional belief during a psychotic episode and imposes it on another person or persons (known as the 'secondary', 'acceptor' or 'associate') with the assumption that the secondary person might not have become deluded if left to his or her own devices. If the parties are admitted to hospital separately, then the delusions in the person with the induced beliefs usually resolve without the need of medication.
- Folie simultanée describes either the situation where two people considered to suffer independently from psychosis influence the content of each other's delusions so they become identical or strikingly similar, or one in which two people "morbidly predisposed" to delusional psychosis mutually trigger symptoms in each other.
Folie à deux and its more populous cousins are in many ways a psychiatric curiosity. The current Diagnostic and Statistical Manual of Mental Disorders
Diagnostic and Statistical Manual of Mental Disorders
The Diagnostic and Statistical Manual of Mental Disorders is published by the American Psychiatric Association and provides a common language and standard criteria for the classification of mental disorders...
states that a person cannot be diagnosed as being delusional if the belief in question is one "ordinarily accepted by other members of the person's culture or subculture" (see entry for delusion
Delusion
A delusion is a false belief held with absolute conviction despite superior evidence. Unlike hallucinations, delusions are always pathological...
). It is not clear at what point a belief considered to be delusional escapes from the folie à... diagnostic category and becomes legitimate because of the number of people holding it. When a large number of people may come to believe obviously false and potentially distressing things based purely on hearsay, these beliefs are not considered to be clinical delusions by the psychiatric profession and are labelled instead as mass hysteria.
In a well-publicised case in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
, the condition was one of two possible diagnoses of a Swedish woman, Sabina Eriksson
Ursula and Sabina Eriksson
Ursula and Sabina Eriksson, born 1967, are a pair of Swedish twins who came to national attention in the United Kingdom in 2008 after an apparent episode of folie à deux which resulted in unique footage of insanity on the M6 motorway and the killing of Glenn Hollinshead. No drugs or alcohol were...
, who stabbed a man to death after he took her into his home, offering food and shelter. Eriksson had just been released from police custody following an incident on a motorway which grabbed news headlines. Caught on camera by a police documentary filmmaker, her twin sister ran into the path of an oncoming articulated lorry, sustaining severe injuries. Eriksson then immediately duplicated her twin's actions by stepping into the path of an oncoming car; she survived the impact. The defence counsel in the ultimate murder trial claimed that Eriksson was a 'secondary' sufferer of folie à deux, influenced by the presence or perceived presence of her twin sister — the 'primary'.
Related phenomena
- Reports have stated that a similar phenomenon to folie à deux had been induced by the military incapacitating agentIncapacitating agentThe term incapacitating agent is defined by the U.S. Department of Defense asLethal agents are primarily intended to kill, but incapacitating agents can also kill if administered in a potent enough dose, or in certain scenarios....
BZ3-Quinuclidinyl benzilate3-quinuclidinyl benzilate , IUPAC name 1-azabicyclo[2.2.2]Oct-3-yl α-hydroxy-α-phenylbenzeneacetate, is an odorless military incapacitating agent. Its NATO code is BZ...
in the late 60s, and most recently again by anthropologists in the South American rainforest consuming the hallucinogen ayahuascaAyahuascaAyahuasca is any of various psychoactive infusions or decoctions prepared from the Banisteriopsis spp. vine, usually mixed with the leaves of dimethyltryptamine-containing species of shrubs from the Psychotria genus...
(Metzner, 1999).
See also
- Codependency
- DelusionDelusionA delusion is a false belief held with absolute conviction despite superior evidence. Unlike hallucinations, delusions are always pathological...
- Delusional disorderDelusional disorderDelusional disorder is an uncommon psychiatric condition in which patients present with circumscribed symptoms of non-bizarre delusions, but with the absence of prominent hallucinations and no thought disorder, mood disorder, or significant flattening of affect...
- Emotional contagionEmotional contagionEmotional contagion is the tendency to catch and feel emotions that are similar to and influenced by those of others. One view developed by John Cacioppo of the underlying mechanism is that it represents a tendency to automatically mimic and synchronize facial expressions, vocalizations, postures,...
- Hysterical contagionHysterical contagionHysterical contagion occurs when a group of people show signs of a physical problem or illness, when in reality there are psychological and social forces at work....
- Mass hysteria
Further reading
- Halgin, R. & Whitbourne, S. (2002) Abnormal Psychology: Clinical Perspectives on Psychological Disorders. McGraw-Hill. ISBN 0072817216
- Enoch, D. & Ball, H. (2001) Folie à deux (et Folie à plusieurs). In Enoch, D. & Ball, H. Uncommon psychiatric syndromes (Fourth edition). London: Arnold. ISBN 0340763884