|
|
|
|
Cannabis (drug)
|
| |
|
| |
Cannabis, also known as marijuana or marihuana, or ganja (from Hindi/Sanskrit: ????? ganja, hemp), is a psychoactive drug extracted from the plant Cannabis sativa, or more often, Cannabis sativa subsp. indica. The herbal form of the drug consists of dried mature flowers and subtending leaves of pistillate (female) plants. The resinous form, known as hashish, consists primarily of glandular trichomes collected from the same plant material.
Discussion
Ask a question about 'Cannabis (drug)' Start a new discussion about 'Cannabis (drug)' Answer questions from other users |
Encyclopedia
Cannabis, also known as marijuana or marihuana, or ganja (from Hindi/Sanskrit: ????? ganja, hemp), is a psychoactive drug extracted from the plant Cannabis sativa, or more often, Cannabis sativa subsp. indica. The herbal form of the drug consists of dried mature flowers and subtending leaves of pistillate (female) plants. The resinous form, known as hashish, consists primarily of glandular trichomes collected from the same plant material. The major biologically active chemical compound in cannabis is ?9-tetrahydrocannabinol (delta-9-tetrahydrocannabinol), commonly referred to as THC.
Humans have been consuming cannabis since prehistory, although in the 20th century there was a rise in its use for recreational, religious or spiritual, and medicinal purposes. It is estimated that about four percent of the world's adult population (162 million) use cannabis annually and 0.6 percent (22.5 million) daily. The possession, use, or sale of psychoactive cannabis products became illegal in most parts of the world in the early 20th century. Since then, some countries have intensified the enforcement of cannabis prohibition while others have reduced the priority of enforcement.
Forms
Marijuana
- Marijuana or ganja: the flowering tops of female plants, from less than 1% THC to 22% THC; the wide range is probably one of the reasons for the conflicting results from different studies.
Psychoactive potency by cannabis plant part is approximately as follows (descending order):
- Trichomes
- Female flowering buds
- Male flowering buds
- New shoots
- Leaves from flower buds
- Leaves in ascending order of size
- Stems of leaves (petioles) in ascending order of size
- Stems in ascending order of size
- Roots and seeds
Hashish
- Hashish (pressed kief) or charas: a concentrated resin composed of heated glandular trichomes that have been physically extracted, usually by rubbing, sifting, or with ice.
Kief
(1) The sticky resin-saturated bits of plant before being pressed into hashish.
(2) Moroccan hashish produced in the Rif mountains;
(3) sifted cannabis trichomes consisting of only the glandular "heads" (often incorrectly referred to as "crystals" or "pollen");
(4) the trichomes ("crystals") left at the bottom of a grinder after grinding marijuana, then gathered and smoked.
Hash oil
For example, an ethanol extract of cannabis that has had the ethanol evaporated from it, to leave hash oil.
Resin
When marijuana is smoked, because of THC's adhesive properties resin builds up inside the paraphernalia. It has tar-like properties but still contains THC as well as other cannibinoids. This resin still has all the psychoactive properties of marijuana but is harsher and less healthy on the lungs. Marijuana users typically only smoke resin as a last resort when they have run out of marijuana flowers.
Methods of consumption
Cannabis is consumed in many different ways, most of which either involve inhaling smoke from ignited plant or administering orally.
Various devices exist for smoking cannabis. The most commonly used include screened bowls, bongs, chillums, paper-wrapped joints and cigar-leaf-wrapped blunts. Local methods differ by the preparation of the cannabis plant before use, the parts of the cannabis plant which are used, and the treatment of the smoke before inhalation.
The vaporizer heats herbal cannabis to 365–410 °F (185–210 °C), which causes the active ingredients to evaporate into a gas without burning the plant material (the boiling point of THC is 392 °F (200°C) at 0.02 mmHg pressure, and somewhat higher at standard atmospheric pressure), A lower proportion of toxic chemicals are released than by smoking, although this may vary depending on the design of the vaporizer and the temperature at which it is set.
As an alternative to smoking, cannabis may be consumed orally. However, the cannabis or its extract must be sufficiently heated or dehydrated to cause decarboxylation of its most abundant cannabinoid, tetrahydrocannabinolic acid, into psychoactive THC.
Cannabis material can be leached in high-proof spirits (often grain alcohol) to create a tincture referred to as “Green Dragon”. This process is often employed to make use of low-potency stems and leaves.
Cannabis can also be consumed as a cannabis tea. THC is lipophilic and only slightly water soluble (with a solubility of 2.8 mg per liter), so tea is made by first dissolving the active components in a fat such as milk, cream, butter, which is mixed with hot water to make a tea.
Effects
Cannabis has psychoactive and physiological effects when consumed. The minimum amount of THC required to have a perceptible psychoactive effect is about 10 micrograms per kilogram of body weight. The most common short-term physical and neurological effects include increased heart rate, lowered blood pressureimpairment of psychomotor coordination, concentration, and short-term memory. Long-term effects are less clear.
Classification
While many drugs clearly fall into the category of either stimulant, depressant, hallucinogen, or antipsychotic, cannabis, containing both THC and CBD, exhibits a mix of all properties, leaning towards hallucinogen properties due to THC being the primary constituent.
Health issues
Smoking of cannabis is the most harmful method of consumption, since the inhalation of smoke from organic materials such as cannabis, tobacco, wood and gasoline can cause various health problems.
In comparison, study on cannabis vaporizing found that subjects were "only 40% as likely to report respiratory symptoms as users who do not vaporize, even when age, sex, cigarette use, and amount of cannabis consumed are controlled." Another study found vaporizers to be "a safe and effective cannabinoid delivery system."
A 2007 study by the Canadian government found cannabis smoke contained more toxic substances than tobacco smoke. The study determined that marijuana smoke contained 20 times more ammonia, and five times more hydrogen cyanide and nitrogen oxides than tobacco smoke. In spite of this, recent studies have been unable to demonstrate a direct link between lung cancer and frequent direct inhalation of marijuana smoke. While many researchers have failed to find a correlation, some researchers still conclude that marijuana smoke poses a higher risk of lung cancer than tobacco. Some studies have even shown that the non-intoxicating ingredient CBD found in marijuana may be useful in treating breast cancer.
Cannabis use has been assessed by several studies to be correlated with the development of anxiety, psychosis and depression, however, no causal mechanism has been proven, and the meaning of the correlation and its direction is a subject of debate that has not been resolved in the scientific community. Some studies assess that the causality is more likely to involve a path from cannabis use to psychotic symptoms rather than a path from psychotic symptoms to cannabis use, while others assess the opposite direction of the causality, or hold cannabis to only form parts of a "causal constellation", while not inflicting mental health problems that would not have occurred in the absence of the cannabis use.
Studies have also shown links between heavy long-term use (over five joints daily over several years) and incidence of heart attacks, strokes, as well as abnormalities in the amygdala and hippocampus regions of the brain.
Gateway drug theory
Some claim that trying marijuana increases the probability that users will eventually use harder drugs. This hypothesis has been one of the central pillars of anti-cannabis drug policy in the United States, though the validity and implications of these hypotheses are highly debated. Studies have shown that tobacco smoking is a better predictor of concurrent illicit hard drug use than smoking cannabis.
No widely accepted study has ever demonstrated a cause-and-effect relationship between the use of marijuana and the later use of harder drugs like heroin and cocaine. However, the prevalence of tobacco cigarette advertising and the practice of mixing tobacco and cannabis together in a single large joint, common in Europe and UK, are believed to be a factor in promoting nicotine dependency among young persons investigating cannabis.
A 2005 comprehensive review of the literature on the cannabis gateway hypothesis found that pre-existing traits may predispose users to addiction in general, the availability of multiple drugs in a given setting confounds predictive patterns in their usage, and drug sub-cultures are more influential than cannabis itself. The study called for further research on "social
context, individual characteristics, and drug effects" to discover the actual relationships between cannabis and the use of other drugs.
The main variant of the gateway hypothesis is that people, upon trying cannabis for the first time and not finding it dangerous, are then tempted to try other, harder drugs. In such a scenario, a new user of cannabis who feels there is a difference between anti-drug information and their own experiences will apply this distrust to public information about other, more powerful drugs. Some studies state that while there is no proof for this gateway theory, young cannabis users should still be considered as a risk group for intervention programs. Other findings indicate that hard drug users are likely to be "poly-drug" users, and that interventions must address the use of multiple drugs instead of a single hard drug.
Another gateway hypothesis is that while cannabis is not as harmful or addictive as other drugs, a gateway effect may be detected as a result of the "common factors" involved with using any illegal drug. Because of its illegal status, cannabis users are more likely to be in situations which allow them to become acquainted with people who use and sell other illegal drugs. By this argument, some studies have shown that alcohol and tobacco may be regarded as gateway drugs. However, a more parsimonious explanation could be that cannabis is simply more readily available (and at an earlier age) than illegal hard drugs, and alcohol/tobacco are in turn easier to obtain earlier than cannabis (though the reverse may be true in some areas), thus leading to the "gateway sequence" in those people who are most likely to experiment with any drug offered.
History
Evidence of the inhalation of cannabis smoke can be found as far back as the 3rd millennium BC as indicated by charred cannabis seeds found in a ritual brazier at an ancient burial site in present day Romania. The most famous users of cannabis were the ancient Hindus of India and Nepal. The herb was called ganjika in Sanskrit (?????/????? ganja in modern Indic languages). The ancient drug soma, mentioned in the Vedas as a sacred intoxicating hallucinogen, was sometimes associated with cannabis.
Cannabis was also known to the ancient Assyrians, who discovered its psychoactive properties through the Aryans. Using it in some religious ceremonies, they called it qunubu (meaning "way to produce smoke"), a probable origin of the modern word 'Cannabis'. Cannabis was also introduced by the Aryans to the Scythians and Thracians/Dacians, whose shamans (the kapnobatai—“those who walk on smoke/clouds”) burned cannabis flowers to induce a state of trance. Members of the cult of Dionysus, believed to have originated in Thrace (Bulgaria, Greece and Turkey), are also thought to have inhaled cannabis smoke. In 2003, a leather basket filled with cannabis leaf fragments and seeds was found next to a 2,500- to 2,800-year-old mummified shaman in the northwestern Xinjiang Uygur Autonomous Region of China.
Cannabis has an ancient history of ritual use and is found in pharmacological cults around the world. Hemp seeds discovered by archaeologists at Pazyryk suggest early ceremonial practices like eating by the Scythians occurred during the 5th to 2nd century BCE, confirming previous historical reports by Herodotus. One writer has claimed that cannabis was used as a religious sacrament by ancient Jews and early Christians due to the similarity between the Hebrew word qannabbos (cannabis) and the Hebrew phrase qené bósem (aromatic cane). It was used by Muslims in various Sufi orders as early as the Mamluk period, for example by the Qalandars.
Today, recreational use in the Western world drives a sizable demand for the drug. Cannabis is the largest cash crop in the United States, generating an estimated $36 billion market. Most of the money is spent not on growing and producing but on smuggling the supply to buyers.
The European Monitoring Centre for Drugs and Drug Addiction reports that typical retail prices in Europe for cannabis varies from 2€ to 14€ per gram, with a majority of European countries reporting prices in the range 4–10€. The United Nations Office on Drugs and Crime claims in its 2008 World Drug Report that typical US retail prices are 15 dollars per gram (approximately $430 per ounce).
Medical use
A synthetic form of one chemical in marijuana, ?9-tetrahydrocannabinol (THC), is used as a treatment for a wide range of medical conditions.
In the United States, the FDA has approved marijuana as a treatment for cancer and the symptoms of HIV and influenza. However, comparable authorities in Western Europe, including the Netherlands, have not approved smoked marijuana for any condition or disease. The current view of the United States Food and Drug Administration is that the consumption of isolated compounds (such as cannabinoids) is more effective than smoking or ingesting parts of the plant.
Russo and Grotenhermen report:
Cannabis is established to help with:
- Nausea and vomiting, anorexia, and weight loss.
Cannabis is well-confirmed in treating:
- spasticity, painful conditions, especially neurogenic pain, movement disorders, asthma, glaucoma.
Many other conditions are also indicate cannabis for relief or treatment, but are less confirmed.
Clinical trials conducted by the American Marijuana Policy Project, a pro-cannabis organization, have shown the efficacy of cannabis as a treatment for cancer and AIDS patients, who often suffer from clinical depression, and from nausea and resulting weight loss due to chemotherapy and other aggressive treatments. A synthetic version of the cannabinoid THC named dronabinol has been shown to relieve symptoms of anorexia and reduce agitation in elderly Alzheimer's patients. Dronabinol has been approved for use with anorexia in patients with HIV/AIDS and chemotherapy-related nausea. This drug, while demonstrating the effectiveness of cannabis at combating several disorders, is more expensive and less available than "pot" and has not been shown to be effective or safe.
Glaucoma, a condition of increased pressure within the eyeball causing gradual loss of sight, can be treated with medical marijuana to decrease this intraocular pressure. There has been debate for 25 years on the subject. Some data exist, showing a reduction of IOP in glaucoma patients who smoke marijuana, but the effects are short-lived, and the frequency of doses needed to sustain a decreased IOP can cause systemic toxicity. There is also some concern over its use since it can also decrease blood flow to the optic nerve. Marijuana lowers IOP by acting on a cannabinoid receptor on the ciliary body called the CB receptor. Although marijuana is not a good therapeutic choice for glaucoma patients, it may lead researchers to more effective, safer treatments. A promising study shows that agents targeted to ocular CB receptors can reduce IOP in glaucoma patients who have failed other therapies.
Medical marijuana is also used for analgesia, or pain relief. It is also reported to be beneficial for treating certain neurological illnesses such as epilepsy, and bipolar disorder. Case reports have found that cannabis can relieve tics in people with obsessive compulsive disorder and Tourette syndrome. Patients treated with tetrahydrocannabinol, the main psychoactive chemical found in cannabis, reported a significant decrease in both motor and vocal tics, some of 50% or more. Some decrease in obsessive-compulsive behavior was also found. A recent study has also concluded that cannabinoids found in cannabis might have the ability to prevent Alzheimer's disease. THC has been shown to reduce arterial blockages.
Another potential use for medical marijuana is movement disorders. Marijuana is frequently reported to reduce the muscle spasms associated with multiple sclerosis; this has been acknowledged by the Institute of Medicine, but it noted that these abundant anecdotal reports are not well-supported by clinical data. Evidence from animal studies suggests that there is a possible role for cannabinoids in the treatment of certain types of epileptic seizures. A synthetic version of the major active compound in cannabis, THC, is available in capsule form as the prescription drug dronabinol (Marinol) in many countries. The prescription drug Sativex, an extract of cannabis administered as a sublingual spray, has been approved in Canada for the treatment of multiple sclerosis.
Demographics
New breeding and cultivation techniques
It is often claimed by growers and breeders of herbal cannabis that advances in breeding and cultivation techniques have increased the potency of cannabis since the late 1960s and early '70s, when ?9-tetrahydrocannabinol was discovered and understood. However, potent seedless marijuana such as "Thai sticks" were already available at that time. In fact, the sinsemilla technique of producing high-potency marijuana has been practiced in India for centuries. Sinsemilla (Spanish for "without seed") is the dried, seedless inflorescences of female cannabis plants. Because THC production drops off once pollination occurs, the male plants (which produce little THC themselves) are eliminated before they shed pollen to prevent pollination. Advanced cultivation techniques such as hydroponics, cloning, high-intensity artificial lighting, and the sea of green method are frequently employed as a response (in part) to prohibition enforcement efforts that make outdoor cultivation more risky. These intensive horticultural techniques have led to fewer seeds being present in cannabis and a general increase in potency over the past 20 years. The average levels of THC in marijuana sold in United States rose from 3.5% in 1988 to 7% in 2003 and 8.5% in 2006.
"Skunk" cannabis is a potent strain of cannabis, grown through selective breeding and usually hydroponics, that is a cross-breed of Cannabis sativa and C. indica. Skunk cannabis potency ranges usually from 6% to 15% and rarely as high as 20%. The average THC level in coffeehouses in the Netherlands is about 18–19%.
The average THC content of Skunk #1 is 8.2%; it is a 4-way combination of the cannabis strains Afghani indica, Mexican Gold, Colombian Gold, and Thai: 75% sativa, 25% indica. This was done via extensive breeding by cultivators in California in the 1970s using the traditional outdoor cropping methods used for centuries.
In proposed revisions to cannabis rescheduling in the UK, the government is considering rescheduling cannabis back from C to B. One of the reasons is the high-potency marijuana.
A Dutch double-blind, randomized, placebo-controlled, cross-over study examining male volunteers aged 18–45 years with a self-reported history of regular cannabis use concluded that smoking of cannabis with high THC levels (marijuana with 9–23% THC), as currently sold in coffee shops in the Netherlands, may lead to higher THC blood-serum concentrations. This is reflected by an increase of the occurrence of impaired psychomotor skills, particularly among younger or inexperienced cannabis smokers, who do not adapt their smoking-style to the higher THC content. High THC concentrations in cannabis was associated with a dose-related increase of physical effects (such as increase of heart rate, and decrease of blood pressure) and psychomotor effects (such as reacting more slowly, being less concentrated, making more mistakes during performance testing, having less motor control, and experiencing drowsiness). It was also observed during the study that the effects from a single joint at times lasted for more than eight hours. Reaction times remained impaired five hours after smoking, when the THC serum concentrations were significantly reduced, but still present. The researchers suggested that THC may accululate in blood-serum when cannabis is smoked several times per day.
Another study showed that consumption of 15 mg of ?9-THC resulted in no learning whatsoever occurring over a three-trial selective reminding task after two hours. In several tasks, ?9-THC increased both speed and error rates, reflecting “riskier” speed–accuracy trade-offs.
Various strains of Marijuana
There are hundreds of named strains of Cannabis, but their origins (particularly the drug varieties) are often shrouded in mystery. The names of many legendary strains, such as Panama Red and Purple Haze, are ubiquitous in the pop-culture, but the origins of some of these infamous strains, such as G-13, are acknowledged to be urban legends, and some people even doubt their existence.
Strains of Cannabis:
The names of some strains have become embedded in the mass culture. For example, Chocolate Thai, which was popular in the early 1990s due to its supposed high potency,was adopted as the stage name of a jazz performer whose album The Real McCoy was released in 2006. It should be noted, however, that because there is no state control over the production or sale of Cannabis, many "strains" may in fact be just marketing brands adopted by drug dealers to increase sales.
Legal status
Since the beginning of the 20th century, most countries have enacted laws against the cultivation, possession, or transfer of cannabis for recreational use. These laws have impacted adversely on the cannabis plant's cultivation for non-recreational purposes, but there are many regions where, under certain circumstances, handling of cannabis is legal or licensed. Many jurisdictions have lessened the penalties for possession of small quantities of cannabis, so that it is punished by confiscation or a fine, rather than imprisonment, focusing more on those who traffic the drug on the black market.
In some areas where cannabis use has been historically tolerated, some new restrictions have been put in place, such as the closing of coffee shops near the borders of the Netherlands, closing of coffes shops near secondary schools in the Netherlands and crackdowns on "Pusher Street" in Christiania, Copenhagen in 2004.
Some jurisdictions use free voluntary treatment programs and/or mandatory treatment programs for frequent known users. Simple possession can carry long prison terms in some countries, particularly in East Asia, where the sale of cannabis may lead to a sentence of life in prison or even execution.
Religious use
In India and Nepal, cannabis has been used by some of the wandering Hindu spiritual sadhus for centuries, and in modern times the Rastafari movement has embraced it as a sacrament. Elders of the modern religious movement known as the Ethiopian Zion Coptic Church consider cannabis to be the Eucharist, claiming it as an oral tradition from Ethiopia dating back to the time of Christ, even though the movement was founded in the United States in 1975 and has no ties to either Ethiopia or the Coptic Church. Like the Rastafari, some modern Gnostic Christian sects have asserted that cannabis is the Tree of Life. Other organized religions founded in the 20th century that treat cannabis as a sacrament are the THC Ministry, the Way of Infinite Harmony, Cantheism, the Cannabis Assembly and the Church of Cognizance.
Truth serum
Cannabis was used as a truth serum by the Office of Strategic Services (OSS), a US government intelligence agency formed during World War II. In the early 1940s, it was the most effective truth drug developed at the OSS labs at St. Elizabeths Hospital; it caused a subject "to be loquacious and free in his impartation of information."
In May 1943, Major George Hunter White, head of OSS counter-intelligence operations in the US, arranged a meeting with Augusto Del Gracio, an enforcer for gangster Lucky Luciano. Del Gracio was given cigarettes spiked with THC concentrate from cannabis, and subsequently talked openly about Luciano's heroin operation. On a second occasion the dosage was increased such that Del Gracio passed out for two hours.
Adulterants
Adulterants in cannabis are less common than in other drugs of abuse. Chalk (in the Netherlands) and glass particles (in the UK) have been used at times to make marijuana appear to be higher quality. Increasing the weight of hashish products in Germany with lead caused lead intoxication in at least 29 cannabis users. In the Netherlands two chemical analogs of Sildenafil (Viagra) were found in adulterated marihuana.
Occasionally, claims have been made that a 'hard drug' (such as heroin or cocaine) is added to cannabis, possibly in order to get the users addicted to a drug that is less addictive. However, this is considered a myth as the 'hard drugs' usually cost more gram-for-gram than 'soft drugs' so the dealer would lose money on such an operation.
See also
Further reading
- Bruce Mirken and Neel Makwana (Aston Birmingham):
- Long term impact of Cannabis use of 16 year olds
External links
- Wiktionary appendix of cannabis slang
-
= History
Cannabis was known as a medicinal and psychoactive compound in some early societies, and has been used continuously in many parts of the world. Other societies have developed a social stigma surrounding the drug.
|
| |
|
|
.gif)
