Cannabis, also known as marijuana among
other names, is a
psychoactive drug from the
cannabis plant. Native to Central or South Asia, the cannabis plant has been used as a drug for both
recreational
Recreation is an activity of leisure, leisure being discretionary time. The "need to do something for recreation" is an essential element of human biology and psychology. Recreational activities are often done for enjoyment, amusement, or pleasu ...
and
entheogenic
Entheogens are psychoactive substances that induce alterations in perception, mood, consciousness, cognition, or behavior for the purposes of engendering spiritual development or otherwiseRätsch, Christian, ''The Encyclopedia of Psychoacti ...
purposes and in various
traditional medicine
Traditional medicine (also known as indigenous medicine or folk medicine) comprises medical aspects of traditional knowledge that developed over generations within the folk beliefs of various societies, including indigenous peoples, before the ...
s for centuries.
Tetrahydrocannabinol
Tetrahydrocannabinol (THC) is the principal psychoactive constituent of cannabis and one of at least 113 total cannabinoids identified on the plant. Although the chemical formula for THC (C21H30O2) describes multiple isomers, the term ''TH ...
(THC) is the main psychoactive component of cannabis, which is one of the 483 known compounds in the plant, including at least 65 other
cannabinoids, such as
cannabidiol
Cannabidiol (CBD) is a phytocannabinoid discovered in 1940. It is one of 113 identified cannabinoids in cannabis plants, along with tetrahydrocannabinol (THC), and accounts for up to 40% of the plant's extract. , clinical research on CBD i ...
(CBD). Cannabis can be used by
smoking
Smoking is a practice in which a substance is burned and the resulting smoke is typically breathed in to be tasted and absorbed into the bloodstream. Most commonly, the substance used is the dried leaves of the tobacco plant, which have bee ...
,
vaporizing
Vaporization (or vaporisation) of an element or compound is a phase transition from the liquid phase to vapor. There are two types of vaporization: evaporation and boiling. Evaporation is a surface phenomenon, whereas boiling is a bulk phenomeno ...
,
within food, or
as an extract.
Cannabis has various
mental and physical effects, which include
euphoria,
altered states of mind
An altered state of consciousness (ASC), also called altered state of mind or mind alteration, is any condition which is significantly different from a normal waking state. By 1892, the expression was in use in relation to hypnosis, though there ...
and
sense of time, difficulty concentrating,
impaired short-term memory, impaired
body movement (balance and fine psychomotor control), relaxation, and an increase in
appetite. Onset of effects is felt within minutes when smoked, but may take up to 90 minutes when eaten. The effects last for two to six hours, depending on the amount used. At high doses, mental effects can include
anxiety
Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil and includes feelings of dread over anticipated events. Anxiety is different than fear in that the former is defined as the anticipation of a future threat wh ...
, delusions (including
ideas of reference
Ideas of reference and delusions of reference describe the phenomenon of an individual experiencing innocuous events or mere coincidences and believing they have strong personal significance. It is "the notion that everything one perceives in the ...
),
hallucination
A hallucination is a perception in the absence of an external stimulus that has the qualities of a real perception. Hallucinations are vivid, substantial, and are perceived to be located in external objective space. Hallucination is a combinati ...
s,
panic
Panic is a sudden sensation of fear, which is so strong as to dominate or prevent reason and logical thinking, replacing it with overwhelming feelings of anxiety and frantic agitation consistent with an animalistic fight-or-flight react ...
,
paranoia, and
psychosis. There is a strong relation between cannabis use and the risk of psychosis, though the direction of
causality is debated. Physical effects include increased heart rate, difficulty breathing, nausea, and behavioral problems in children whose mothers used cannabis during pregnancy; short-term side effects may also include
dry mouth and red eyes.
Long-term adverse effects may include addiction, decreased
mental ability in those who started regular use as adolescents, chronic coughing, susceptibility to
respiratory infections, and
cannabinoid hyperemesis syndrome
Cannabinoid hyperemesis syndrome (CHS) is recurrent nausea, vomiting, and cramping abdominal pain that can occur due to prolonged, high-dose cannabis use. These symptoms may be relieved temporarily by taking a hot shower or bath. Complications m ...
.
Cannabis is mostly used recreationally or as a medicinal drug, although it may also be used for spiritual purposes. In 2013, between 128 and 232 million people used cannabis (2.7% to 4.9% of the global population between the ages of 15 and 65). It is the most commonly used largely-illegal drug in the world, with the highest use among adults in
Zambia
Zambia (), officially the Republic of Zambia, is a landlocked country at the crossroads of Central, Southern and East Africa, although it is typically referred to as being in Southern Africa at its most central point. Its neighbours are th ...
, the
United States,
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by total ...
, and
Nigeria
Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf of G ...
, .
While cannabis plants have been grown since at least the 3rd millennium BCE, evidence suggests that it was being smoked for psychoactive effects at least 2,500 years ago in the
Pamir Mountains, Asia. Since the 14th century, cannabis has been subject to legal restrictions. The possession, use, and cultivation of cannabis has been
illegal in most countries since the 20th century. In 2013,
Uruguay
Uruguay (; ), officially the Oriental Republic of Uruguay ( es, República Oriental del Uruguay), is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast; while bordering ...
became the first country to
legalize recreational use of cannabis. Other countries to do so are Canada,
Georgia
Georgia most commonly refers to:
* Georgia (country), a country in the Caucasus region of Eurasia
* Georgia (U.S. state), a state in the Southeast United States
Georgia may also refer to:
Places
Historical states and entities
* Related to th ...
,
Malta
Malta ( , , ), officially the Republic of Malta ( mt, Repubblika ta' Malta ), is an island country in the Mediterranean Sea. It consists of an archipelago, between Italy and Libya, and is often considered a part of Southern Europe. It lies ...
,
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Gua ...
,
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countr ...
, and
Thailand. In the U.S., the recreational use of cannabis is legalized in
21 states, two territories, and the
District of Columbia, though the drug remains
federally illegal. In
Australia, it is legalized only in the
Australian Capital Territory
The Australian Capital Territory (commonly abbreviated as ACT), known as the Federal Capital Territory (FCT) until 1938, is a landlocked federal territory of Australia containing the national capital Canberra and some surrounding townships. I ...
.
Uses
Medical

Medical cannabis, or medical marijuana, refers to the use of cannabis to treat disease or improve symptoms; however, there is no single agreed-upon definition (e.g.,
cannabinoids derived from cannabis and synthetic cannabinoids are also used).
The rigorous scientific study of cannabis as a medicine has been hampered by production restrictions and by the fact that it is classified as an illegal drug by many governments. There is limited evidence suggesting cannabis can be used to
reduce nausea and vomiting during
chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs ( chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemothera ...
, to improve appetite in people with
HIV/AIDS
Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual ma ...
, or to treat
chronic pain and
muscle spasms. Its use for other medical applications is insufficient for drawing conclusions about safety or efficacy.
There is evidence supporting the use of cannabis or its derivatives in the treatment of chemotherapy-induced nausea and vomiting, neuropathic pain, and multiple sclerosis. Lower levels of evidence support its use for AIDS
wasting syndrome
Cachexia () is a complex syndrome associated with an underlying illness, causing ongoing muscle loss that is not entirely reversed with nutritional supplementation. A range of diseases can cause cachexia, most commonly cancer, congestive heart ...
, epilepsy, rheumatoid arthritis, and glaucoma.
So far, the medical use of cannabis is legal only in a limited number of territories, including Canada,
[ ]Belgium
Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to th ...
, Australia, the Netherlands
)
, anthem = ( en, "William of Nassau")
, image_map =
, map_caption =
, subdivision_type = Sovereign state
, subdivision_name = Kingdom of the Netherlands
, established_title = Before independence
, established_date = Spanish Nether ...
, New Zealand, Spain, and many U.S. states. This usage generally requires a prescription, and distribution is usually done within a framework defined by local laws.
Recreational
According to DEA Chief Administrative Law Judge, Francis Young, "cannabis is one of the safest therapeutically active substances known to man." Being under the effects of cannabis is usually referred to as being "high" or "stoned." Cannabis consumption has both psychoactive and physiological effects. The "stoned" experience can vary widely, based (among other things) on the user's prior experience with cannabis, and the type of cannabis consumed. When smoking cannabis, a euphoriant effect can occur within minutes of smoking. Aside from a subjective change in perception and mood, the most common short-term physical and neurological effects include increased heart rate, increased appetite, impairment of short-term and working memory, and psychomotor coordination.
Additional desired effects from consuming cannabis include relaxation, a general alteration of conscious perception, increased awareness of sensation, increased libido and distortions in the perception of time and space. At higher doses, effects can include altered body image, auditory and/or visual illusion
An illusion is a distortion of the senses, which can reveal how the mind normally organizes and interprets sensory stimulation. Although illusions distort the human perception of reality, they are generally shared by most people.
Illusions may ...
s, pseudohallucinations and ataxia from selective impairment of polysynaptic reflexes. In some cases, cannabis can lead to dissociative states such as depersonalization
Depersonalization can consist of a detachment within the self, regarding one's mind or body, or being a detached observer of oneself. Subjects feel they have changed and that the world has become vague, dreamlike, less real, lacking in significa ...
and derealization
Derealization is an alteration in the perception of the external world, causing those with the condition to perceive it as unreal, distant, distorted or falsified. Other symptoms include feeling as if one's environment is lacking in spontaneity, ...
.
Spiritual
Cannabis has held sacred status in several religions and has served as an entheogen – a chemical substance used in religious, shamanic
Shamanism is a religious practice that involves a practitioner (shaman) interacting with what they believe to be a spirit world through altered states of consciousness, such as trance. The goal of this is usually to direct spirits or spirit ...
, or spiritual contexts – in the Indian subcontinent since the Vedic period
The Vedic period, or the Vedic age (), is the period in the late Bronze Age and early Iron Age of the history of India when the Vedic literature, including the Vedas (ca. 1300–900 BCE), was composed in the northern Indian subcontinent, betw ...
. The earliest known reports regarding the sacred status of cannabis in the Indian subcontinent come from the Atharva Veda, estimated to have been composed sometime around 1400 BCE.
The Hindu god Shiva
Shiva (; sa, शिव, lit=The Auspicious One, Śiva ), also known as Mahadeva (; ɐɦaːd̪eːʋɐ, or Hara, is one of the principal deities of Hinduism. He is the Supreme Being in Shaivism, one of the major traditions within Hindu ...
is described as a cannabis user, known as the "Lord of bhang.
In modern culture, the spiritual use of cannabis has been spread by the disciples of the Rastafari movement
Rastafari, sometimes called Rastafarianism, is a religion that developed in Jamaica during the 1930s. It is classified as both a new religious movement and a social movement by scholars of religion. There is no central authority in control o ...
who use cannabis as a sacrament and as an aid to meditation.[
]
Consumption
Modes of consumption
Cannabis is consumed in many different ways, all of which involve heating to decarboxylate
Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO2). Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain. The reverse process, which is t ...
THCA in the plant into THC. Common available forms are:
* Smoking
Smoking is a practice in which a substance is burned and the resulting smoke is typically breathed in to be tasted and absorbed into the bloodstream. Most commonly, the substance used is the dried leaves of the tobacco plant, which have bee ...
, which typically involves burning and inhaling vaporized cannabinoids ("smoke") from small pipes, bongs (portable versions of hookah
A hookah (Hindustani language, Hindustani: (Nastaleeq), (Devanagari), IPA: ; also see #Names and etymology, other names), shisha, or waterpipe is a single- or multi-stemmed instrument for heating or vaporizing and then smoking either tobacco ...
s with a water chamber), paper-wrapped joints or tobacco-leaf-wrapped blunts, and other items.
* Vaporizer
Vaporizer or vaporiser may refer to:
* Anesthetic vaporizer, a device used in the administration of anesthesia
*Electronic cigarette, or a part of one (often called a "PV" or "personal vaporizer")
*Humidifier, a household appliance that increases ...
, which heats any form of cannabis to , causing the active ingredients to evaporate into vapor
In physics, a vapor (American English) or vapour (British English and Canadian English; see spelling differences) is a substance in the gas phase at a temperature lower than its critical temperature,R. H. Petrucci, W. S. Harwood, and F. G. Her ...
without burning the plant material (the boiling point of THC
Tetrahydrocannabinol (THC) is the principal psychoactive constituent of cannabis and one of at least 113 total cannabinoids identified on the plant. Although the chemical formula for THC (C21H30O2) describes multiple isomers, the term ''THC'' ...
is at atmospheric pressure).
* Cannabis tea, which contains relatively small concentrations of THC because THC is an oil (lipophilic
Lipophilicity (from Greek λίπος "fat" and φίλος "friendly"), refers to the ability of a chemical compound to dissolve in fats, oils, lipids, and non-polar solvents such as hexane or toluene. Such non-polar solvents are themselves lipo ...
) and is only slightly water-soluble (with a solubility of 2.8 mg per liter). Cannabis tea is made by first adding a saturated fat
A saturated fat is a type of fat in which the fatty acid chains have all single bonds. A fat known as a glyceride is made of two kinds of smaller molecules: a short glycerol backbone and fatty acids that each contain a long linear or branched ch ...
to hot water (e.g. cream or any milk except skim) with a small amount of cannabis.
* Edibles, where cannabis is added as an ingredient to one of a variety of foods, including butter and baked goods. In India it is commonly made into a beverage, bhang.
* Tincture of cannabis
Tincture of cannabis, sometimes known as green dragon, is an alcoholic cannabis concentrate. The solubility of THC in ethanol is greater than 1 g/mL.
Cannabis tinctures are used in the production of specific extracts, like nabiximols.
Histor ...
, sometimes known as green dragon, is an alcoholic cannabis concentrate.
* Capsules, typically containing cannabis oil
Hash oil or cannabis oil, is an oleoresin obtained by the extraction of cannabis or hashish. It is a cannabis concentrate containing many of its resins and terpenes – in particular, tetrahydrocannabinol (THC), cannabidiol (CBD), and other c ...
, and other dietary supplement
A dietary supplement is a manufactured product intended to supplement one's diet by taking a pill, capsule, tablet, powder, or liquid. A supplement can provide nutrients either extracted from food sources or that are synthetic in order ...
products, for which some 220 were approved in Canada in 2018.
Onset of effects is felt within minutes when smoked, and may take up to 90 minutes when eaten. Depending on the amount used, the effects last for two to six hours.
Consumption by country
In 2013, between 128 and 232 million people used cannabis (2.7% to 4.9% of the global population between the ages of 15 and 65). Cannabis is by far the most widely used illicit substance, with the highest use among adults () in Zambia
Zambia (), officially the Republic of Zambia, is a landlocked country at the crossroads of Central, Southern and East Africa, although it is typically referred to as being in Southern Africa at its most central point. Its neighbours are th ...
, the United States, Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by total ...
, and Nigeria
Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf of G ...
.
United States
Between 1973 and 1978, eleven states decriminalized marijuana. In 2001, Nevada reduced marijuana possession to a misdemeanor and since 2012, several other states have decriminalized and even legalized marijuana.
In 2018, almost half of the people in the United States had tried marijuana, 16% had used it in the past year, and 11% had used it in the past month. In 2014, daily marijuana use amongst US college students had reached its highest level since records began in 1980, rising from 3.5% in 2007 to 5.9% in 2014 and had surpassed daily cigarette use.
In the US, men are over twice as likely to use marijuana as women, and 1829-year-olds are six times more likely to use as over-65-year-olds. In 2015, a record 44% of the US population has tried marijuana in their lifetime, an increase from 38% in 2013 and 33% in 1985.
Marijuana use in the United States is three times above the global average, but in line with other Western democracies. Forty-four percent of American 12th graders have tried the drug at least once, and the typical age of first-use is 16, similar to the typical age of first-use for alcohol but lower than the first-use age for other illicit drugs.
Adverse effects
Addiction
Short-term
Acute negative effects may include anxiety and panic, impaired attention and memory, an increased risk of psychotic symptoms, the inability to think clearly, and an increased risk of accidents. Cannabis impairs a person's driving ability, and THC
Tetrahydrocannabinol (THC) is the principal psychoactive constituent of cannabis and one of at least 113 total cannabinoids identified on the plant. Although the chemical formula for THC (C21H30O2) describes multiple isomers, the term ''THC'' ...
was the illicit drug most frequently found in the blood of drivers who have been involved in vehicle crashes. Those with THC in their system are from three to seven times more likely to be the cause of the accident than those who had not used either cannabis or alcohol, although its role is not necessarily causal because THC stays in the bloodstream for days to weeks after intoxication.
Some immediate undesired side effects include a decrease in short-term memory, dry mouth, impaired motor skills, reddening of the eyes, dizziness, feeling tired and vomiting.[ Some users may experience an episode of acute psychosis, which usually abates after six hours, but in rare instances, heavy users may find the symptoms continuing for many days.]
Legalization has increased the rates at which children are exposed to cannabis, particularly from edibles. While the toxicity and lethality of THC in children is not known, they are at risk for encephalopathy, hypotension, respiratory depression severe enough to require ventilation, somnolence and coma.
Fatality
Cannabis is suspected of being a potential, and under-reported, contributory factor or direct cause in cases of sudden death
Death is the irreversible cessation of all biological functions that sustain an organism. For organisms with a brain, death can also be defined as the irreversible cessation of functioning of the whole brain, including brainstem, and brain ...
, due to the strain it can place on the cardiovascular system
The blood circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, tha ...
. Multiple deaths have been attributed to cannabinoid hyperemesis syndrome
Cannabinoid hyperemesis syndrome (CHS) is recurrent nausea, vomiting, and cramping abdominal pain that can occur due to prolonged, high-dose cannabis use. These symptoms may be relieved temporarily by taking a hot shower or bath. Complications m ...
.
A 16-month survey of Oregon and Alaska emergency departments found a report of the death of an adult who had been admitted for acute cannabis toxicity.
Long-term
Psychological effects
A 2015 meta-analysis found that, although a longer period of abstinence was associated with smaller magnitudes of impairment, both retrospective and prospective memory were impaired in cannabis users. The authors concluded that some, but not all, of the deficits associated with cannabis use were reversible. A 2012 meta-analysis found that deficits in most domains of cognition persisted beyond the acute period of intoxication, but was not evident in studies where subjects were abstinent for more than 25 days. Few high quality studies have been performed on the long-term effects of cannabis on cognition, and the results were generally inconsistent. Furthermore, effect sizes of significant findings were generally small. One review concluded that, although most cognitive faculties were unimpaired by cannabis use, residual deficits occurred in executive functions. Impairments in executive functioning are most consistently found in older populations, which may reflect heavier cannabis exposure, or developmental effects associated with adolescent cannabis use. One review found three prospective cohort studies that examined the relationship between self-reported cannabis use and intelligence quotient (IQ). The study following the largest number of heavy cannabis users reported that IQ declined between ages 7–13 and age 38. Poorer school performance and increased incidence of leaving school early were both associated with cannabis use, although a causal relationship was not established. Cannabis users demonstrated increased activity in task-related brain regions, consistent with reduced processing efficiency.
A reduced quality of life
Quality of life (QOL) is defined by the World Health Organization as "an individual's perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards ...
is associated with heavy cannabis use, although the relationship is inconsistent and weaker than for tobacco and other substances. The direction of cause and effect, however, is unclear.[
The long-term effects of cannabis are not clear.][ There are concerns surrounding memory and cognition problems, risk of addiction, and the risk of ]schizophrenia
Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social withd ...
in young people.[
]
=Neuroimaging
=
Although global abnormalities in white matter
White matter refers to areas of the central nervous system (CNS) that are mainly made up of myelinated axons, also called tracts. Long thought to be passive tissue, white matter affects learning and brain functions, modulating the distribution ...
and grey matter are not consistently associated with heavy cannabis use, reduced hippocampal
The hippocampus (via Latin from Greek , 'seahorse') is a major component of the brain of humans and other vertebrates. Humans and other mammals have two hippocampi, one in each side of the brain. The hippocampus is part of the limbic system, an ...
volume is consistently found. Amygdala
The amygdala (; plural: amygdalae or amygdalas; also '; Latin from Greek, , ', 'almond', 'tonsil') is one of two almond-shaped clusters of nuclei located deep and medially within the temporal lobes of the brain's cerebrum in complex verteb ...
abnormalities are sometimes reported, although findings are inconsistent.
Cannabis use is associated with increased recruitment of task-related areas, such as the dorsolateral prefrontal cortex
The dorsolateral prefrontal cortex (DLPFC or DL-PFC) is an area in the prefrontal cortex of the primate brain. It is one of the most recently derived parts of the human brain. It undergoes a prolonged period of maturation which lasts until adult ...
, which is thought to reflect compensatory activity due to reduced processing efficiency. Cannabis use is also associated with downregulation of CB1 receptors. The magnitude of down regulation is associated with cumulative cannabis exposure, and is reversed after one month of abstinence. There is limited evidence that chronic cannabis use can reduce levels of glutamate
Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can syn ...
metabolites in the human brain.
Cannabis dependence
About 9% of those who experiment with marijuana eventually become dependent according to DSM-IV (1994) criteria. A 2013 review estimates daily use is associated with a 10–20% rate of dependence. The highest risk of cannabis dependence is found in those with a history of poor academic achievement, deviant behavior in childhood and adolescence, rebelliousness, poor parental relationships, or a parental history of drug and alcohol problems. Of daily users, about 50% experience withdrawal upon cessation of use (i.e. are dependent), characterized by sleep problems, irritability, dysphoria, and craving. Cannabis withdrawal is less severe than withdrawal from alcohol.
According to DSM-V
The ''Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition'' (DSM-5), is the 2013 update to the '' Diagnostic and Statistical Manual of Mental Disorders'', the taxonomic and diagnostic tool published by the American Psychiatr ...
criteria, 9% of those who are exposed to cannabis develop cannabis use disorder, compared to 20% for cocaine
Cocaine (from , from , ultimately from Quechua: ''kúka'') is a central nervous system (CNS) stimulant mainly used recreationally for its euphoric effects. It is primarily obtained from the leaves of two Coca species native to South Ameri ...
, 23% for alcohol and 68% for nicotine
Nicotine is a naturally produced alkaloid in the nightshade family of plants (most predominantly in tobacco and ''Duboisia hopwoodii'') and is widely used recreationally as a stimulant and anxiolytic. As a pharmaceutical drug, it is used for ...
. Cannabis use disorder in the DSM-V involves a combination of DSM-IV criteria for cannabis abuse and dependence, plus the addition of craving, without the criterion related to legal troubles.
Psychiatric
At an epidemiological level, a dose–response relationship
The dose–response relationship, or exposure–response relationship, describes the magnitude of the response of an organism, as a function of exposure (or doses) to a stimulus or stressor (usually a chemical) after a certain exposure tim ...
exists between cannabis use and increased risk of psychosis and earlier onset of psychosis. Although the epidemiological association is robust, evidence to prove a causal relationship is lacking. But a biological causal pathway is plausible, especially if there is a genetic predisposition to mental illness, in which case cannabis may be a trigger.
Cannabis may also increase the risk of depression, but insufficient research has been performed to draw a conclusion. Cannabis use is associated with increased risk of anxiety disorders, although causality has not been established.
A review in 2019 found that research was insufficient to determine the safety and efficacy of using cannabis to treat schizophrenia, psychosis, or other mental disorder
A mental disorder, also referred to as a mental illness or psychiatric disorder, is a behavioral or mental pattern that causes significant distress or impairment of personal functioning. Such features may be persistent, relapsing and remitti ...
s. Another found that cannabis during adolescence was associated with an increased risk of developing depression and suicidal behavior later in life, while finding no effect on anxiety.
Physical
Heavy, long-term exposure to marijuana may have physical, mental, behavioral and social health consequences. It may be "associated with diseases of the liver (particularly with co-existing hepatitis C), lungs, heart, and vasculature". A 2014 review found that while cannabis use may be less harmful than alcohol use, the recommendation to substitute it for problematic drinking was premature without further study. Various surveys conducted between 2015 and 2019 found that many users of cannabis substitute it for prescription drugs (including opioids), alcohol, and tobacco; most of those who used it in place of alcohol or tobacco either reduced or stopped their intake of the latter substances.
Cannabinoid hyperemesis syndrome
Cannabinoid hyperemesis syndrome (CHS) is recurrent nausea, vomiting, and cramping abdominal pain that can occur due to prolonged, high-dose cannabis use. These symptoms may be relieved temporarily by taking a hot shower or bath. Complications m ...
(CHS) is a severe condition seen in some chronic cannabis users where they have repeated bouts of uncontrollable vomiting for 24–48 hours.
Four cases of death have been reported as a result of CHS.
A limited number of studies have examined the effects of cannabis smoking on the respiratory system. Chronic heavy marijuana smoking is associated with respiratory infections, coughing, production of sputum, wheezing, and other symptoms of chronic bronchitis. The available evidence does not support a causal relationship between cannabis use and chronic obstructive pulmonary disease. Short-term use of cannabis is associated with bronchodilation
A bronchodilator or broncholytic (although the latter occasionally includes secretory inhibition as well) is a substance that dilates the bronchi and bronchioles, decreasing resistance in the respiratory airway and increasing airflow to the lun ...
. Other side effects of cannabis use include cannabinoid hyperemesis syndrome
Cannabinoid hyperemesis syndrome (CHS) is recurrent nausea, vomiting, and cramping abdominal pain that can occur due to prolonged, high-dose cannabis use. These symptoms may be relieved temporarily by taking a hot shower or bath. Complications m ...
(CHS), a condition which involves recurrent nausea, cramping abdominal pain, and vomiting.
Cannabis smoke contains thousands of organic and inorganic chemical compounds. This tar
Tar is a dark brown or black viscous liquid of hydrocarbons and free carbon, obtained from a wide variety of organic materials through destructive distillation. Tar can be produced from coal, wood, petroleum, or peat. "a dark brown or black b ...
is chemically similar to that found in tobacco smoke, and over fifty known carcinogens have been identified in cannabis smoke, including; nitrosamines, reactive aldehydes, and polycylic hydrocarbons, including benz yrene. Cannabis smoke is also inhaled more deeply than tobacco smoke. , there is no consensus regarding whether cannabis smoking is associated with an increased risk of cancer. Light and moderate use of cannabis is not believed to increase risk of lung or upper airway cancer. Evidence for causing these cancers is mixed concerning heavy, long-term use. In general there are far lower risks of pulmonary complications for regular cannabis smokers when compared with those of tobacco. A 2015 review found an association between cannabis use and the development of testicular germ cell tumor
Germ cell tumor (GCT) is a neoplasm derived from germ cells. Germ-cell tumors can be cancerous or benign. Germ cells normally occur inside the gonads (ovary and testis). GCTs that originate outside the gonads may be birth defects resulting from er ...
s (TGCTs), particularly non-seminoma
A seminoma is a germ cell tumor of the testicle or, more rarely, the mediastinum or other extra-gonadal locations. It is a malignant neoplasm and is one of the most treatable and curable cancers, with a survival rate above 95% if discovered in ...
TGCTs. Another 2015 meta-analysis found no association between lifetime cannabis use and risk of head or neck cancer. Combustion products are not present when using a vaporizer
Vaporizer or vaporiser may refer to:
* Anesthetic vaporizer, a device used in the administration of anesthesia
*Electronic cigarette, or a part of one (often called a "PV" or "personal vaporizer")
*Humidifier, a household appliance that increases ...
, consuming THC in pill form, or consuming cannabis foods
A cannabis edible, also known as a cannabis-infused food or simply an edible, is a food product (either homemade or produced commercially) that contains decarboxylated cannabinoids (cannabinoid acids converted to their orally bioactive form) ...
.
There is concern that cannabis may contribute to cardiovascular disease, but , evidence of this relationship was unclear. Research in these events is complicated because cannabis is often used in conjunction with tobacco, and drugs such as alcohol and cocaine that are known to have cardiovascular risk factors. Smoking cannabis has also been shown to increase the risk of myocardial infarction by 4.8 times for the 60 minutes after consumption.
There is preliminary evidence that cannabis interferes with the anticoagulant
Anticoagulants, commonly known as blood thinners, are chemical substances that prevent or reduce coagulation of blood, prolonging the clotting time. Some of them occur naturally in blood-eating animals such as leeches and mosquitoes, where t ...
properties of prescription drugs used for treating blood clots. , the mechanisms for the anti-inflammatory and possible pain relieving effects of cannabis were not defined, and there were no governmental regulatory approvals or clinical practices for use of cannabis as a drug.[
]
=Emergency department visits
=
Emergency room (ER) admissions associated with cannabis use rose significantly from 2012 to 2016; adolescents from age 12–17 had the highest risk. At one Colorado medical center following legalization, approximately two percent of ER admissions were classified as cannabis users. The symptoms of one quarter of these users were partially attributed to cannabis (a total of 2567 out of 449,031 patients); other drugs were sometimes involved. Of these cannabis admissions, one quarter were for acute psychiatric effects, primarily suicidal ideation
Suicidal ideation, or suicidal thoughts, means having thoughts, ideas, or ruminations about the possibility of ending one's own life.World Health Organization, ''ICD-11 for Mortality and Morbidity Statistics'', ver. 09/2020MB26.A Suicidal ideatio ...
, depression, and anxiety. An additional third of the cases were for gastrointestinal issues including Cannabinoid hyperemesis syndrome
Cannabinoid hyperemesis syndrome (CHS) is recurrent nausea, vomiting, and cramping abdominal pain that can occur due to prolonged, high-dose cannabis use. These symptoms may be relieved temporarily by taking a hot shower or bath. Complications m ...
.
According to the United States Department of Health and Human Services, there were 455,000 emergency room visits associated with cannabis use in 2011. These statistics include visits in which the patient was treated for a condition induced by or related to recent cannabis use. The drug use must be "implicated" in the emergency department visit, but does not need to be the direct cause of the visit. Most of the illicit drug emergency room visits involved multiple drugs. In 129,000 cases, cannabis was the only implicated drug.
Reproductive health
There is sufficient evidence of reproductive health harms from cannabis that its use when trying to conceive, during pregnancy, and while breastfeeding, is not advisable.
It has been recommended that cannabis use be stopped before and during pregnancy as it can result in negative outcomes for both the mother and baby, such as behavioral problems. However, maternal use of marijuana during pregnancy does not appear to be associated with low birth weight or early delivery after controlling for tobacco use and other confounding factors.
Pharmacology
Mechanism of action
The high lipid-solubility of cannabinoids results in their persisting in the body for long periods of time. Even after a single administration of THC, detectable levels of THC can be found in the body for weeks or longer (depending on the amount administered and the sensitivity of the assessment method). Investigators have suggested that this is an important factor in marijuana's effects, perhaps because cannabinoids may accumulate in the body, particularly in the lipid membranes of neurons.
Researchers confirmed that THC exerts its most prominent effects via its actions on two types of cannabinoid receptors, the CB1 receptor and the CB2 receptor, both of which are G protein-coupled receptors. The CB1 receptor is found primarily in the brain as well as in some peripheral tissues, and the CB2 receptor is found primarily in peripheral tissues, but is also expressed in neuroglia
Glia, also called glial cells (gliocytes) or neuroglia, are non-neuronal cells in the central nervous system (brain and spinal cord) and the peripheral nervous system that do not produce electrical impulses. They maintain homeostasis, form myel ...
l cells. THC appears to alter mood and cognition through its agonist actions on the CB1 receptors, which inhibit a secondary messenger system (adenylate cyclase
Adenylate cyclase (EC 4.6.1.1, also commonly known as adenyl cyclase and adenylyl cyclase, abbreviated AC) is an enzyme with systematic name ATP diphosphate-lyase (cyclizing; 3′,5′-cyclic-AMP-forming). It catalyzes the following reaction:
: ...
) in a dose-dependent manner.
Via CB1 receptor activation, THC indirectly increases dopamine
Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. Dopamine constitutes about 80% o ...
release and produces psychotropic
A psychoactive drug, psychopharmaceutical, psychoactive agent or psychotropic drug is a chemical substance, that changes functions of the nervous system, and results in alterations in perception, mood, consciousness, cognition or behavior.
T ...
effects. CBD also acts as an allosteric modulator
In pharmacology and biochemistry, allosteric modulators are a group of substances that bind to a receptor to change that receptor's response to stimulus. Some of them, like benzodiazepines, are drugs. The site that an allosteric modulator binds to ...
of the μ- and δ-opioid receptor
The δ-opioid receptor, also known as delta opioid receptor or simply delta receptor, abbreviated DOR or DOP, is an inhibitory 7-transmembrane G-protein coupled receptor coupled to the G protein Gi/G0 and has enkephalins as its endogenous lig ...
s. THC also potentiates the effects of the glycine receptors. It is unknown if or how these actions contribute to the effects of cannabis.
Chemistry
Chemical composition
The main psychoactive component of cannabis is tetrahydrocannabinol
Tetrahydrocannabinol (THC) is the principal psychoactive constituent of cannabis and one of at least 113 total cannabinoids identified on the plant. Although the chemical formula for THC (C21H30O2) describes multiple isomers, the term ''TH ...
(THC), which is formed via decarboxylation of tetrahydrocannabinolic acid (THCA) from the application of heat. Raw leaf is not psychoactive because the cannabinoids are in the form of carboxylic acids. THC is one of the 483 known compounds in the plant, including at least 65 other cannabinoids, such as cannabidiol
Cannabidiol (CBD) is a phytocannabinoid discovered in 1940. It is one of 113 identified cannabinoids in cannabis plants, along with tetrahydrocannabinol (THC), and accounts for up to 40% of the plant's extract. , clinical research on CBD i ...
(CBD).
Detection in body fluids
THC and its major (inactive) metabolite, THC-COOH, can be measured in blood, urine, hair, oral fluid or sweat using chromatographic
In chemical analysis, chromatography is a laboratory technique for the separation of a mixture into its components. The mixture is dissolved in a fluid solvent (gas or liquid) called the ''mobile phase'', which carries it through a system (a ...
techniques as part of a drug use testing program or a forensic investigation of a traffic or other criminal offense. The concentrations obtained from such analyses can often be helpful in distinguishing active use from passive exposure, elapsed time since use, and extent or duration of use. These tests cannot, however, distinguish authorized cannabis smoking for medical purposes from unauthorized recreational smoking. Commercial cannabinoid immunoassay
An immunoassay (IA) is a biochemical test that measures the presence or concentration of a macromolecule or a small molecule in a solution through the use of an antibody (usually) or an antigen (sometimes). The molecule detected by the immunoassay ...
s, often employed as the initial screening method when testing physiological specimens for marijuana presence, have different degrees of cross-reactivity with THC and its metabolites. Urine contains predominantly THC-COOH, while hair, oral fluid and sweat contain primarily THC. Blood may contain both substances, with the relative amounts dependent on the recency and extent of usage.
The Duquenois–Levine test is commonly used as a screening test
Screening, in medicine, is a strategy used to look for as-yet-unrecognised conditions or risk markers. This testing can be applied to individuals or to a whole population. The people tested may not exhibit any signs or symptoms of a disease, or t ...
in the field, but it cannot definitively confirm the presence of cannabis, as a large range of substances have been shown to give false positives. Researchers at John Jay College of Criminal Justice reported that dietary zinc supplements can mask the presence of THC and other drugs in urine. However, a 2013 study conducted by researchers at the University of Utah School of Medicine refute the possibility of self-administered zinc producing false-negative urine drug tests.
Varieties and strains
CBD is a 5-HT1A receptor agonist, which is under laboratory research to determine if it has an anxiolytic effect. It is often claimed that sativa strains provide a more stimulating psychoactive high while indica strains are more sedating with a body high. However, this is disputed by researchers.
A 2015 review found that the use of high CBD-to-THC strains of cannabis showed significantly fewer positive symptoms
Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showin ...
, such as delusions and hallucinations, better cognitive function
Cognitive skills, also called cognitive functions, cognitive abilities or cognitive capacities, are brain-based skills which are needed in acquisition of knowledge, manipulation of information and reasoning. They have more to do with the mechanisms ...
and both lower risk for developing psychosis, as well as a later age of onset of the illness, compared to cannabis with low CBD-to-THC ratios.
Psychoactive ingredients
According to the United Nations Office on Drugs and Crime
The United Nations Office on Drugs and Crime (UNODC; French: ''Office des Nations unies contre la drogue et le crime'') is a United Nations office that was established in 1997 as the Office for Drug Control and Crime Prevention by combining the ...
(UNODC), "the amount of THC present in a cannabis sample is generally used as a measure of cannabis potency." The three main forms of cannabis products are the flower/fruit, resin (hashish), and oil (hash oil). The UNODC states that cannabis often contains 5% THC content, resin "can contain up to 20% THC content", and that "Cannabis oil may contain more than 60% THC content."
A 2012 review found that the THC content in marijuana had increased worldwide from 1970 to 2009. It is unclear, however, whether the increase in THC content has caused people to consume more THC or if users adjust based on the potency of the cannabis. It is likely that the higher THC content allows people to ingest less tar. At the same time, CBD levels in seized samples have lowered, in part because of the desire to produce higher THC levels and because more illegal growers cultivate indoors using artificial lights. This helps avoid detection but reduces the CBD production of the plant.
Australia's National Cannabis Prevention and Information Centre (NCPIC) states that the buds ( infructescences) of the female cannabis plant contain the highest concentration of THC, followed by the leaves. The stalks and seeds have "much lower THC levels". The UN states that the leaves can contain ten times less THC than the buds, and the stalks one hundred times less THC.
After revisions to cannabis scheduling in the UK, the government moved cannabis back from a class C to a class B drug. A purported reason was the appearance of high potency cannabis. They believe skunk
Skunks are mammals in the family Mephitidae. They are known for their ability to spray a liquid with a strong, unpleasant scent from their anal glands. Different species of skunk vary in appearance from black-and-white to brown, cream or gi ...
accounts for between 70 and 80% of samples seized by police (despite the fact that skunk can sometimes be incorrectly mistaken for all types of herbal cannabis). Extracts such as hashish
Hashish ( ar, حشيش, ()), also known as hash, "dry herb, hay" is a drug made by compressing and processing parts of the cannabis plant, typically focusing on flowering buds (female flowers) containing the most trichomes. European Monitorin ...
and hash oil typically contain more THC than high potency cannabis infructescences.
Laced cannabis and synthetic cannabinoids
Hemp buds (or low-potency cannabis buds) laced with synthetic cannabinoids started to be sold as cannabis street drug in 2020.
The short-term effects of cannabis can be altered if it has been laced with opioid drugs such as heroin or fentanyl. The added drugs are meant to enhance the psychoactive properties, add to its weight, and increase profitability, despite the increased danger of overdose.
Preparations
File:Marijuana-Cannabis-Weed-Bud-Gram.jpg, Dried flower buds (marijuana)
File:Kief (yellow).jpg, A gram of kief
File:Hashish-2.jpg, Hashish
File:Drop of cannabis oil.jpg, Hash oil
File:Cannabis Butter.JPG, Infusion (dairy butter)
Marijuana
Marijuana or marihuana (herbal cannabis) consists of the dried flowers and fruits and subtending leaves and stems of the female cannabis plant. This is the most widely consumed form, containing 3% to 20% THC, with reports of up to 33% THC. This is the stock material from which all other preparations are derived. Although herbal cannabis and industrial hemp
Hemp, or industrial hemp, is a botanical class of ''Cannabis sativa'' cultivars grown specifically for industrial or medicinal use. It can be used to make a wide range of products. Along with bamboo, hemp is among the fastest growing plants o ...
derive from the same species and contain the psychoactive component (THC), they are distinct strains with unique biochemical compositions and uses. Hemp has lower concentrations of THC and higher concentrations of CBD, which gives lesser psychoactive effects.
Kief
Kief is a powder, rich in trichome
Trichomes (); ) are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae. A covering of any kind of hair on a plant ...
s, which can be sifted from the leaves, flowers and fruits of cannabis plants and either consumed in powder form or compressed to produce cakes of hashish
Hashish ( ar, حشيش, ()), also known as hash, "dry herb, hay" is a drug made by compressing and processing parts of the cannabis plant, typically focusing on flowering buds (female flowers) containing the most trichomes. European Monitorin ...
. The word "kif" derives from colloquial Arabic
The varieties (or dialects or vernacular languages) of Arabic, a Semitic language within the Afroasiatic family originating in the Arabian Peninsula, are the linguistic systems that Arabic speakers speak natively. There are considerable varia ...
', meaning ''pleasure''.
Hashish
Hashish (also spelled hasheesh, hashisha, or simply hash) is a concentrated resin
In polymer chemistry and materials science, resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. Resins are usually mixtures of organic compounds. This article focuses on natu ...
cake or ball produced from pressed kief, the detached trichomes and fine material that falls off cannabis fruits, flowers and leaves. or from scraping the resin from the surface of the plants and rolling it into balls. It varies in color from black to golden brown depending upon purity and variety of cultivar it was obtained from. It can be consumed orally or smoked, and is also vaporized, or 'vaped'. The term "rosin hash" refers to a high quality solventless product obtained through heat and pressure.
Tincture
Cannabinoids can be extracted from cannabis plant matter using high- proof spirits
Spirit or spirits may refer to:
Liquor and other volatile liquids
* Spirits, a.k.a. liquor, distilled alcoholic drinks
* Spirit or tincture, an extract of plant or animal material dissolved in ethanol
* Volatile (especially flammable) liquids, ...
(often grain alcohol
Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a hyd ...
) to create a tincture
A tincture is typically an extract of plant or animal material dissolved in ethanol (ethyl alcohol). Solvent concentrations of 25–60% are common, but may run as high as 90%.Groot Handboek Geneeskrachtige Planten by Geert Verhelst In chemistr ...
, often referred to as "green dragon". Nabiximols
Nabiximols (USAN, trade name Sativex) is a specific ''Cannabis'' extract that was approved in 2010 as a botanical drug in the United Kingdom. Nabiximols is sold as a mouth spray intended to alleviate neuropathic pain, spasticity, overactive blad ...
is a branded product name from a tincture manufacturing pharmaceutical company.
Hash oil
Hash oil is a resin
In polymer chemistry and materials science, resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. Resins are usually mixtures of organic compounds. This article focuses on natu ...
ous matrix of cannabinoids obtained from the cannabis plant by solvent extraction
A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for ...
, formed into a hardened or viscous mass. Hash oil can be the most potent of the main cannabis products because of its high level of psychoactive compound per its volume, which can vary depending on the plant's mix of essential oils and psychoactive compounds. Butane and supercritical carbon dioxide hash oil have become popular in recent years.
Infusions
There are many varieties of cannabis infusions owing to the variety of non-volatile solvents used. The plant material is mixed with the solvent and then pressed and filtered to express the oils of the plant into the solvent. Examples of solvents used in this process are cocoa butter, dairy butter, cooking oil, glycerine
Glycerol (), also called glycerine in British English and glycerin in American English, is a simple triol compound. It is a colorless, odorless, viscous liquid that is sweet-tasting and non-toxic. The glycerol backbone is found in lipids known ...
, and skin moisturizers. Depending on the solvent, these may be used in cannabis foods
A cannabis edible, also known as a cannabis-infused food or simply an edible, is a food product (either homemade or produced commercially) that contains decarboxylated cannabinoids (cannabinoid acids converted to their orally bioactive form) ...
or applied topically.
Marihuana prensada
''Marihuana prensada'' ('pressed marijuana') is a cannabis-derived product widespread among the lower classes of South America, especially from the 90s. Locally it is known as "paraguayo" or "paragua", since its main producer is Paraguay. Marijuana is dried and mixed with binding agents that make it toxic and highly harmful to health. It is cut into the shape of bricks (''ladrillos'') and sold for a low price in Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
, Brazil, Chile, Peru
, image_flag = Flag of Peru.svg
, image_coat = Escudo nacional del Perú.svg
, other_symbol = Great Seal of the State
, other_symbol_type = Seal (emblem), National seal
, national_motto = "Fi ...
, Venezuela, and even the United States.
History
Ancient history
Cannabis is indigenous to Central or South Asia and its uses for fabric and rope dates back to the Neolithic age in China and Japan. It is unclear when cannabis first became known for its psychoactive properties. The oldest archeological evidence for the burning of cannabis was found in Romanian kurgan
A kurgan is a type of tumulus constructed over a grave, often characterized by containing a single human body along with grave vessels, weapons and horses. Originally in use on the Pontic–Caspian steppe, kurgans spread into much of Central As ...
s dated 3,500 BC, and scholars suggest that the drug was first used in ritual ceremonies by Proto-Indo-European
Proto-Indo-European (PIE) is the reconstructed common ancestor of the Indo-European language family. Its proposed features have been derived by linguistic reconstruction from documented Indo-European languages. No direct record of Proto-Indo ...
tribes living in the Pontic-Caspian steppe during the Chalcolithic
The Copper Age, also called the Chalcolithic (; from grc-gre, χαλκός ''khalkós'', "copper" and ''líthos'', "stone
In geology, rock (or stone) is any naturally occurring solid mass or aggregate of minerals or mineraloi ...
period, a custom they eventually spread throughout Western Eurasia during the Indo-European migrations. Some research suggests that the ancient Indo-Iranian drug soma
Soma may refer to:
Businesses and brands
* SOMA (architects), a New York–based firm of architects
* Soma (company), a company that designs eco-friendly water filtration systems
* SOMA Fabrications, a builder of bicycle frames and other bicycl ...
, mentioned in the Veda
upright=1.2, The Vedas are ancient Sanskrit texts of Hinduism. Above: A page from the '' Atharvaveda''.
The Vedas (, , ) are a large body of religious texts originating in ancient India. Composed in Vedic Sanskrit, the texts constitute the ...
s, sometimes contained cannabis. This is based on the discovery of a basin containing cannabis in a shrine of the second millennium BC in Turkmenistan.
Cannabis was known to the ancient Assyrians, who discovered its psychoactive properties through the Iranians. Using it in some religious ceremonies, they called it ''qunubu'' (meaning "way to produce smoke"), a probable origin of the modern word "cannabis". The Iranians also introduced cannabis to the Scythians, Thracians
The Thracians (; grc, Θρᾷκες ''Thrāikes''; la, Thraci) were an Indo-European speaking people who inhabited large parts of Eastern and Southeastern Europe in ancient history.. "The Thracians were an Indo-European people who occupied ...
and Dacians, whose shamans (the ''kapnobatai
Kapnobatai or capnobatae ( grc, καπνοβάται; la, capnobatae), meaning "''those who walk on/in smoke/clouds''" was one of the names given to the Mysians of Thrace (geographical and historical region in Southeast Europe, now split among Bul ...
''"those who walk on smoke/clouds") burned cannabis infructescences to induce trance
Trance is a state of semi-consciousness in which a person is not self-aware and is either altogether unresponsive to external stimuli (but nevertheless capable of pursuing and realizing an aim) or is selectively responsive in following the dir ...
. The plant was used in China before 2800 BC, and found therapeutic use in India by 1000 BC, where it was used in food and drink, including '' bhang''.
Cannabis has an ancient history of ritual use and has been used by religions around the world. It has been used as a drug for both recreational
Recreation is an activity of leisure, leisure being discretionary time. The "need to do something for recreation" is an essential element of human biology and psychology. Recreational activities are often done for enjoyment, amusement, or pleasu ...
and entheogenic
Entheogens are psychoactive substances that induce alterations in perception, mood, consciousness, cognition, or behavior for the purposes of engendering spiritual development or otherwiseRätsch, Christian, ''The Encyclopedia of Psychoacti ...
purposes and in various traditional medicines for centuries. The earliest evidence of cannabis smoking has been found in the 2,500-year-old tombs of Jirzankal Cemetery in the Pamir Mountains in Western China, where cannabis residue were found in burners with charred pebbles possibly used during funeral rituals. Hemp seeds discovered by archaeologists at Pazyryk suggest early ceremonial practices like eating by the Scythians occurred during the 5th to 2nd century BC, confirming previous historical reports by Herodotus. It was used by Muslims in various Sufi
Sufism ( ar, ''aṣ-ṣūfiyya''), also known as Tasawwuf ( ''at-taṣawwuf''), is a mystic body of religious practice, found mainly within Sunni Islam but also within Shia Islam, which is characterized by a focus on Islamic spirituality, r ...
orders as early as the Mamluk period, for example by the Qalandars. Smoking pipes uncovered in Ethiopia and carbon-dated to around AD 1320 were found to have traces of cannabis.
Modern history
Cannabis was introduced to the New World
The term ''New World'' is often used to mean the majority of Earth's Western Hemisphere, specifically the Americas."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: Oxford University Press, p. 3 ...
by the Spaniards in 1530–1545. Following an 1836–1840 travel in North Africa and the Middle East, French physician Jacques-Joseph Moreau wrote on the psychological effects of cannabis use; he founded the Paris' Club des Hashischins in 1844. In 1842, Irish physician William Brooke O'Shaughnessy, who had studied the drug while working as a medical officer in Bengal with the East India Company
The East India Company (EIC) was an English, and later British, joint-stock company founded in 1600 and dissolved in 1874. It was formed to trade in the Indian Ocean region, initially with the East Indies (the Indian subcontinent and South ...
, brought a quantity of cannabis with him on his return to Britain
Britain most often refers to:
* The United Kingdom, a sovereign state in Europe comprising the island of Great Britain, the north-eastern part of the island of Ireland and many smaller islands
* Great Britain, the largest island in the United King ...
, provoking renewed interest in the West. Examples of classic literature of the period featuring cannabis include '' Les paradis artificiels'' (1860) by Charles Baudelaire and '' The Hasheesh Eater'' (1857) by Fitz Hugh Ludlow.
Cannabis was criminalized in some countries beginning in the 14th century and was illegal in most countries by the middle of the 20th century. The colonial government of Mauritius banned cannabis in 1840 over concerns on its effect on Indian indentured workers; the same occurred in Singapore in 1870. In the United States, the first restrictions on sale of cannabis came in 1906 (in the District of Columbia). Canada criminalized cannabis in ''The Opium and Narcotic Drug Act, 1923'', before any reports of the use of the drug in Canada, but eventually legalized its consumption for recreational and medicinal purposes in 2018.[
In 1925, a compromise was made at an international conference in The Hague about the International Opium Convention that banned exportation of "Indian hemp" to countries that had prohibited its use, and requiring importing countries to issue certificates approving the importation and stating that the shipment was required "exclusively for medical or scientific purposes". It also required parties to "exercise an effective control of such a nature as to prevent the illicit international traffic in Indian hemp and especially in the resin". In the United States in 1937, the ]Marihuana Tax Act
The Marihuana Tax Act of 1937, , was a United States Act that placed a tax on the sale of cannabis. The H.R. 6385 act was drafted by Harry Anslinger and introduced by Rep. Robert L. Doughton of North Carolina, on April 14, 1937. The Seventy-fi ...
was passed, and prohibited the production of hemp in addition to cannabis.
In 1972, the Dutch government divided drugs into more- and less-dangerous categories, with cannabis being in the lesser category. Accordingly, possession of or less was made a misdemeanor. Cannabis has been available for recreational use in coffee shops since 1976. Cannabis products are only sold openly in certain local "coffeeshops" and possession of up to for personal use is decriminalized, however: the police may still confiscate it, which often happens in car checks near the border. Other types of sales and transportation are not permitted, although the general approach toward cannabis was lenient even before official decriminalization
Decriminalization or decriminalisation is the reclassification in law relating to certain acts or aspects of such to the effect that they are no longer considered a crime, including the removal of criminal penalties in relation to them. This refor ...
.
In Uruguay, President Jose Mujica signed legislation to legalize recreational cannabis in December 2013, making Uruguay the first country in the modern era to legalize cannabis. In August 2014, Uruguay legalized growing up to six plants at home, as well as the formation of growing clubs ( Cannabis social club), and a state-controlled marijuana dispensary regime.
, when recreational use of cannabis was legalized in Canada, dietary supplement
A dietary supplement is a manufactured product intended to supplement one's diet by taking a pill, capsule, tablet, powder, or liquid. A supplement can provide nutrients either extracted from food sources or that are synthetic in order ...
s for human use and veterinary health products containing not more than 10 parts per million of THC extract were approved for marketing; Nabiximols
Nabiximols (USAN, trade name Sativex) is a specific ''Cannabis'' extract that was approved in 2010 as a botanical drug in the United Kingdom. Nabiximols is sold as a mouth spray intended to alleviate neuropathic pain, spasticity, overactive blad ...
(as Sativex) is used as a prescription drug in Canada.[
The United Nations' ''World Drug Report'' stated that cannabis "was the world's most widely produced, trafficked, and consumed drug in the world in 2010", and estimated between 128 million and 238 million users globally in 2015.
]
Culture, legality and economics
Culture
Cannabis has been one of the most used psychoactive drugs in the world since the late 20th century, following only tobacco
Tobacco is the common name of several plants in the genus '' Nicotiana'' of the family Solanaceae, and the general term for any product prepared from the cured leaves of these plants. More than 70 species of tobacco are known, but the ...
and alcohol in popularity.[Rubin, 1975. p. 1] According to Vera Rubin, the use of cannabis has been encompassed by two major cultural complexes over time: a continuous, traditional folk
Folk or Folks may refer to:
Sociology
*Nation
*People
* Folklore
** Folk art
** Folk dance
** Folk hero
** Folk music
*** Folk metal
*** Folk punk
*** Folk rock
** Folk religion
* Folk taxonomy
Arts, entertainment, and media
* Folk Plus or Fol ...
stream, and a more circumscribed, contemporary configuration.[Rubin, 1975. p. 3] The former involves both sacred and secular use, and is usually based on small-scale cultivation: the use of the plant for cordage
Cordage may refer to:
* Rigging, cords and ropes attached to masts and sails on a ship or boat
* Rope
A rope is a group of yarns, plies, fibres, or strands that are twisted or braided together into a larger and stronger form. Ropes have ...
, clothing, medicine, food, and a "general use as an euphoriant
Euphoria ( ) is the experience (or affect) of pleasure or excitement and intense feelings of well-being and happiness. Certain natural rewards and social activities, such as aerobic exercise, laughter, listening to or making music and d ...
and symbol of fellowship."[Rubin, 1975. p. 4] The second stream of expansion of cannabis use encompasses "the use of hemp for commercial manufacturers utilizing large-scale cultivation primarily as a fiber for mercantile purposes"; but it is also linked to the search for psychedelic experience
A psychedelic experience (known colloquially as a trip) is a temporary altered state of consciousness induced by the consumption of a psychedelic substance (most commonly LSD, mescaline, psilocybin mushrooms, or DMT). For example, an acid t ...
s (which can be traced back to the formation of the Parisian Club des Hashischins).
Legality
Since the beginning of the 20th century, most countries have enacted laws
Law is a set of rules that are created and are enforceable by social or governmental institutions to regulate behavior,Robertson, ''Crimes against humanity'', 90. with its precise definition a matter of longstanding debate. It has been vari ...
against the cultivation, possession or transfer of cannabis. These laws have had an adverse effect on cannabis cultivation for non-recreational purposes, but there are many regions where 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 and sometimes a fine, rather than imprisonment, focusing more on those who traffic the drug on the black market
A black market, underground economy, or shadow economy is a clandestine market or series of transactions that has some aspect of illegality or is characterized by noncompliance with an institutional set of rules. If the rule defines the s ...
.
In some areas where cannabis use had been historically tolerated, new restrictions were instituted, such as the closing of cannabis coffee shops near the borders of the Netherlands, and closing of coffee shops near secondary schools in the Netherlands. In Copenhagen
Copenhagen ( or .; da, København ) is the capital and most populous city of Denmark, with a proper population of around 815.000 in the last quarter of 2022; and some 1.370,000 in the urban area; and the wider Copenhagen metropolitan ar ...
, Denmark in 2014, mayor Frank Jensen discussed possibilities for the city to legalize cannabis production and commerce.
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. Political parties, non-profit organizations, and causes based on the legalization of medical cannabis and/or legalizing the plant entirely (with some restrictions) have emerged in such countries as China and Thailand.
In December 2012, the U.S. state of Washington
Washington commonly refers to:
* Washington (state), United States
* Washington, D.C., the capital of the United States
** A metonym for the federal government of the United States
** Washington metropolitan area, the metropolitan area centered o ...
became the first state to officially legalize cannabis in a state law (Washington Initiative 502
Washington Initiative 502 (I-502) "on marijuana reform" was an initiative to the Washington State Legislature, which appeared on the November 2012 general ballot, passing by a margin of approximately 56 to 44 percent. Originally submitted to ...
) (but still illegal by federal law), with the state of Colorado
Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...
following close behind ( Colorado Amendment 64). On 1 January 2013, the first marijuana "club
Club may refer to:
Arts, entertainment, and media
* ''Club'' (magazine)
* Club, a '' Yie Ar Kung-Fu'' character
* Clubs (suit), a suit of playing cards
* Club music
* "Club", by Kelsea Ballerini from the album '' kelsea''
Brands and enterpris ...
" for private marijuana smoking (no buying or selling, however) was allowed for the first time in Colorado. The California Supreme Court decided in May 2013 that local governments can ban medical marijuana dispensaries despite a state law in California that permits the use of cannabis for medical purposes. At least 180 cities across California have enacted bans in recent years.
In December 2013, Uruguay
Uruguay (; ), officially the Oriental Republic of Uruguay ( es, República Oriental del Uruguay), is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast; while bordering ...
became the first country to legalize growing, sale and use of cannabis. After a long delay in implementing the retail component of the law, in 2017 sixteen pharmacies were authorized to sell cannabis commercially. On 19 June 2018, the Canadian Senate passed a bill and the Prime Minister announced the effective legalization date as 17 October 2018.[ Canada is the second country to legalize the drug.
In November 2015, ]Uttarakhand
Uttarakhand ( , or ; , ), also known as Uttaranchal ( ; the official name until 2007), is a state in the northern part of India. It is often referred to as the "Devbhumi" (literally 'Land of the Gods') due to its religious significance and ...
became the first state of India to legalize the cultivation of hemp for industrial purposes. Usage within the Hindu and Buddhist cultures of the Indian subcontinent is common, with many street vendors in India openly selling products infused with cannabis, and traditional medical practitioners in Sri Lanka selling products infused with cannabis for recreational purposes and well as for religious celebrations. Indian laws criminalizing cannabis date back to the colonial period. India and Sri Lanka have allowed cannabis to be taken in the context of traditional culture for recreational/celebratory purposes and also for medicinal purposes.
On 17 October 2015, Australian health minister Sussan Ley presented a new law that will allow the cultivation of cannabis for scientific research and medical trials on patients.
On 17 October 2018, Canada legalized cannabis for recreational adult use making it the second country in the world to do so after Uruguay and the first G7 nation. The Canadian Licensed Producer system aims to become the Gold Standard in the world for safe and secure cannabis production, including provisions for a robust craft cannabis industry where many expect opportunities for experimenting with different strains. Laws around use vary from province to province including age limits, retail structure, and growing at home.
As the drug has increasingly been seen as a health issue instead of criminal behavior, marijuana has also been legalized or decriminalized in: Czech Republic,[ "''Podle čl. 36 Jednotné úmluvy o omamných látkách ze dne 31. března 1961 (č. 47/1965 Sb.) se signatáři zavazují k trestnímu postihu tam uvedených forem nakládání s drogami včetně jejich držby. Návrh upouští od dosavadní beztrestnosti držby omamných a psychotropních látek a jedů pro svoji potřebu. Dosavadní beztrestnost totiž eliminuje v řadě případů možnost postihu dealerů a distributorů drog.''"] Colombia
Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Carib ...
, Ecuador, Portugal, South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countr ...
and Canada.[ Medical marijuana was legalized in Mexico in mid-2017; legislators plan to legalize its recreational use by late 2019.
On 28 June 2021, ]Clarence Thomas
Clarence Thomas (born June 23, 1948) is an American jurist who serves as an associate justice of the Supreme Court of the United States. He was nominated by President George H. W. Bush to succeed Thurgood Marshall and has served since 19 ...
, one of the U.S. Supreme Court
The Supreme Court of the United States (SCOTUS) is the highest court in the federal judiciary of the United States. It has ultimate appellate jurisdiction over all U.S. federal court cases, and over state court cases that involve a point ...
's most conservative justices, possibly opened the door to federal legalization of cannabis in the United States when he wrote "A prohibition on interstate use or cultivation of marijuana may no longer be necessary or proper to support the federal government's piecemeal approach."
Legal status by country
As of 2022, Uruguay
Uruguay (; ), officially the Oriental Republic of Uruguay ( es, República Oriental del Uruguay), is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast; while bordering ...
and Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by total ...
are the only countries that have fully legalized the cultivation, consumption and bartering of recreational cannabis nationwide. In the United States, 21 states, 2 territories, and the District of Columbia have legalized the recreational use of cannabis – though the drug remains illegal at the federal level. Laws vary from state to state when it comes to the commercial sale. Court rulings in Georgia
Georgia most commonly refers to:
* Georgia (country), a country in the Caucasus region of Eurasia
* Georgia (U.S. state), a state in the Southeast United States
Georgia may also refer to:
Places
Historical states and entities
* Related to th ...
and South Africa have led to the legalization of cannabis consumption, but not legal sales. A policy of limited enforcement has also been adopted in many countries, in particular Spain and the Netherlands
)
, anthem = ( en, "William of Nassau")
, image_map =
, map_caption =
, subdivision_type = Sovereign state
, subdivision_name = Kingdom of the Netherlands
, established_title = Before independence
, established_date = Spanish Nether ...
where the sale of cannabis is tolerated at licensed establishments. Contrary to popular belief, cannabis is not legal in the Netherlands, but it has been decriminalized since the 1970s. In 2021, Malta
Malta ( , , ), officially the Republic of Malta ( mt, Repubblika ta' Malta ), is an island country in the Mediterranean Sea. It consists of an archipelago, between Italy and Libya, and is often considered a part of Southern Europe. It lies ...
was the first European Union
The European Union (EU) is a supranational political and economic union of member states that are located primarily in Europe. The union has a total area of and an estimated total population of about 447million. The EU has often been de ...
member to legalize the use of cannabis for recreational purposes. In Estonia, it is only legal to sell cannabis products with a THC content of less than 0.2%, although products may contain more cannabidiol. Lebanon has recently become the first Arab country to legalize the plantation of cannabis for medical use.
Penalties for illegal recreational use ranges from confiscation or small fines to jail time and even death. In some countries citizens can be punished if they have used the drug in another country, including Singapore and South Korea.
Economics
Production
''Sinsemilla'' (Spanish for "without seed") is the dried, seedless (i.e. parthenocarpic
In botany and horticulture, parthenocarpy is the natural or artificially induced production of fruit without fertilisation of ovules, which makes the fruit seedless. Stenospermocarpy may also produce apparently seedless fruit, but the seeds are ...
) infructescences 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, thus inducing the development of parthenocarpic
In botany and horticulture, parthenocarpy is the natural or artificially induced production of fruit without fertilisation of ovules, which makes the fruit seedless. Stenospermocarpy may also produce apparently seedless fruit, but the seeds are ...
fruits gathered in dense infructescences. Advanced cultivation techniques such as hydroponics, cloning
Cloning is the process of producing individual organisms with identical or virtually identical DNA, either by natural or artificial means. In nature, some organisms produce clones through asexual reproduction. In the field of biotechnology, ...
, 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.
"Skunk" refers to several named strains of potent cannabis, grown through selective breeding and sometimes hydroponics. It is a cross-breed of ''Cannabis sativa'' and ''C. indica'' (although other strains of this mix exist in abundance). Skunk cannabis potency ranges usually from 6% to 15% and rarely as high as 20%. The average THC level in coffee shops in the Netherlands is about 18–19%.
The average levels of THC in cannabis sold in the United States rose dramatically between the 1970s and 2000. This is disputed for various reasons, and there is little consensus as to whether this is a fact or an artifact of poor testing methodologies. According to Daniel Forbes writing for slate.com, the relative strength of modern strains are likely skewed because undue weight is given to much more expensive and potent, but less prevalent, samples. Some suggest that results are skewed by older testing methods that included low-THC-content plant material such as leaves in the samples, which are excluded in contemporary tests. Others believe that modern strains actually are significantly more potent than older ones.
The main producing countries of cannabis are Afghanistan, Canada, China, Colombia, India, Jamaica, Lebanon, Mexico,[ Morocco,] the Netherlands, Pakistan, Paraguay, Spain, Thailand, Turkey, the United Kingdom, and the United States.
Price
The price or street value of cannabis varies widely depending on geographic area and potency. Prices and overall markets have also varied considerably over time.
* In 1997, cannabis was estimated to be overall the number four value crop in the US, and number one or two in many states, including California, New York, and Florida. This estimate is based on a value to growers of ~60% of retail value, or .
* In 2006, cannabis was estimated to have been a $36 billion market. This estimate has been challenged as exaggerated. The UN World Drug Report (2008) estimated that 2006 street prices in the US and Canada ranged from about US$8.8 to $25 per gram (approximately $250 to $700 per ounce), depending on quality. Typical U.S. retail prices were $10–15 per gram (approximately $280–420 per ounce).
* In 2017, the U.S. was estimated to constitute 90% of the worldwide $9.5 billion legal trade in cannabis.
After some U.S. states legalized cannabis, street prices began to drop. In Colorado, the price of smokable buds (infructescences) dropped 40 percent between 2014 and 2019, from $200 per ounce to $120 per ounce ($7 per gram to $4.19 per gram).
The European Monitoring Centre for Drugs and Drug Addiction reports that typical retail prices in Europe for cannabis varied from €2 to €20 per gram in 2008, with a majority of European countries reporting prices in the range €4–10.
Cannabis as a gateway drug
The gateway hypothesis states that cannabis use increases the probability of trying "harder" drugs. The hypothesis has been hotly debated as it is regarded by some as the primary rationale for the United States prohibition on cannabis use. A Pew Research Center poll found that political opposition to marijuana use was significantly associated with concerns about the health effects and whether legalization would increase weed use by children.
Some studies state that while there is no proof for the gateway hypothesis, 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. Almost two-thirds of the poly drug users in the 2009–2010 Scottish Crime and Justice Survey used cannabis.
The gateway effect may appear due to social factors involved in using any illegal drug. Because of the illegal status of cannabis, its consumers are likely to find themselves in situations allowing them to acquaint with individuals using or selling other illegal drugs. Studies have shown that alcohol and tobacco may additionally 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. In turn, alcohol and tobacco are typically easier to obtain at an earlier age than is cannabis (though the reverse may be true in some areas), thus leading to the "gateway sequence" in those individuals, since they are most likely to experiment with any drug offered.
A related alternative to the gateway hypothesis is the common liability to addiction (CLA) theory. It states that some individuals are, for various reasons, willing to try multiple recreational substances. The "gateway" drugs are merely those that are (usually) available at an earlier age than the harder drugs. Researchers have noted in an extensive review that it is dangerous to present the sequence of events described in gateway "theory" in causative terms as this hinders both research and intervention.
In 2020, the National Institute on Drug Abuse released a study backing allegations that marijuana is a gateway to harder drugs, though not for the majority of marijuana users. The National Institute on Drug Abuse determined that marijuana use is "likely to precede use of other licit and illicit substances" and that "adults who reported marijuana use during the first wave of the survey were more likely than adults who did not use marijuana to develop an alcohol use disorder within 3 years; people who used marijuana and already had an alcohol use disorder at the outset were at greater risk of their alcohol use disorder worsening. Marijuana use is also linked to other substance use disorders including nicotine addiction." It also reported that "These findings are consistent with the idea of marijuana as a "gateway drug." However, the majority of people who use marijuana do not go on to use other, "harder" substances. Also, cross-sensitization is not unique to marijuana. Alcohol and nicotine also prime the brain for a heightened response to other drugs and are, like marijuana, also typically used before a person progresses to other, more harmful substances."
Research
Research on cannabis is challenging since the plant is illegal in most countries. Research-grade samples of the drug are difficult to obtain for research purposes, unless granted under authority of national regulatory agencies, such as the US Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food s ...
.
There are also other difficulties in researching the effects of cannabis. Many people who smoke cannabis also smoke tobacco. This causes confounding factors, where questions arise as to whether the tobacco, the cannabis, or both that have caused a cancer. Another difficulty researchers have is in recruiting people who smoke cannabis into studies. Because cannabis is an illegal drug in many countries, people may be reluctant to take part in research, and if they do agree to take part, they may not say how much cannabis they actually smoke.
See also
* Cannabis rights
* Glossary of cannabis terms
References
Footnotes
Citations
External links
*
* Wiktionary Appendix of Cannabis slang
{{DEFAULTSORT:Cannabis (Drug)
Appetite stimulants
Cannabis smoking
Entheogens
Euphoriants
Herbalism
Medicinal plants
Psychoactive drugs