Cannabis (drug)/ja: Difference between revisions

<div lang="en" dir="ltr" class="mw-content-ltr">

=== Modes of consumption ===

[[File:Unrolled joint.jpg|thumb|upright=1.2|A joint prior to rolling, with a paper handmade filter on the left]]{{Cookbook|Cannabis}}

Many different ways to consume cannabis involve heat to [[Decarboxylation|decarboxylate]] [[Tetrahydrocannabinolic acid|THCA]] into THC; common modes include:

* [[Cannabis smoking|Smoking]], involves burning and inhaling cannabinoids ("smoke") from [[One hitter (smoking)|small pipes]], [[bong]]s (portable versions of [[hookah]]s with a water chamber), paper-wrapped [[joint (cannabis)|joints]], tobacco-leaf-wrapped [[Blunt (cannabis)|blunts]], or the like.

* [[Vaporizer (inhalation device)|Vaporizing]], heating various forms of cannabis to {{convert|165|–|190|°C|°F}}, causing the active ingredients to form [[vapor]] without combustion of the plant material (the boiling point of [[tetrahydrocannabinol|THC]] is {{convert|157|°C|°F}} at atmospheric pressure).

* [[Cannabis foods|Edibles]], adding cannabis as an ingredient to a wide variety of foods, including butter and baked goods. In India it is commonly consumed as the beverage [[bhang]].

* [[Cannabis tea]], prepared with attention to the [[lipophilic]] quality of THC, which is only slightly water-soluble (2.8&nbsp;mg per liter), often involving cannabis in a [[saturated fat]].

* [[Tincture of cannabis]], sometimes known as green dragon, is an [[tincture|alcoholic]] [[cannabis concentrate]].

* [[Capsule (pharmacy)|Capsules]], typically containing [[hash oil|cannabis oil]], and other [[dietary supplement]] products, for which some 220 were approved in Canada in 2018.

<div lang="en" dir="ltr" class="mw-content-ltr">

=== Consumption by country ===

{{main|Annual cannabis use 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 ({{as of|2018|lc=y}}) in [[Cannabis in Zambia|Zambia]], the [[Cannabis in the United States|United States]], [[Cannabis in Canada|Canada]], and [[Cannabis in Nigeria|Nigeria]].

====United States====

Between 1973 and 1978, eleven states decriminalized marijuana. In 2001, [[Cannabis in Nevada|Nevada]] reduced marijuana possession to a misdemeanor and since 2012, several other states have decriminalized and even legalized marijuana.

In 2018, surveys indicated that 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, surveys said 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 18{{ndash}}29-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.

A 2022 [[Gallup, Inc.|Gallup]] poll concluded Americans are smoking more marijuana than cigarettes for the first time.

<div lang="en" dir="ltr" class="mw-content-ltr">

== Adverse effects ==

{{Further|Effects of cannabis}}

<div lang="en" dir="ltr" class="mw-content-ltr">

===Short-term===

[[File:Bodily effects of cannabis.svg|thumb|upright=1.1|Main short-term physical effects of cannabis]]

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 [[Tetrahydrocannabinol|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.

<div lang="en" dir="ltr" class="mw-content-ltr">

===Fatality===

A systematic meta analysis showed that cannabis users double the chance of dying from heart disease.  Cannabis users had a 29% higher risk of heart attack and a 20% higher risk of stroke than non-users. There is an association between cannabis use and suicide, particularly in younger users.

A recent study in 2025 suggests that individuals diagnosed with cannabis use disorder—characterized by an inability to stop using cannabis despite its negative effects—face a nearly threefold increase in [[mortality rate]]s compared to those without the condition over a five-year period. The research indicates that people with this disorder are ten times more likely to die by suicide than the general population. Additionally, they have a higher risk of death from trauma, drug poisoning, and lung cancer. In a separate study researchers found an increase in [[schizophrenia]] and [[psychosis]] cases in [[Canada]] linked to cannabis use disorder following the drug’s legalization.

===Long-term===

{{main|Long-term effects of cannabis}}

[[File:Rational harm assessment of drugs radar plot.svg|thumb|Addiction experts in psychiatry, chemistry, pharmacology, forensic science, epidemiology, and the police and legal services engaged in [[Delphi method|delphic analysis]] regarding 20 popular recreational drugs. Cannabis was ranked 11th in dependence, 17th in physical harm, and 10th in social harm.]]

<div lang="en" dir="ltr" class="mw-content-ltr">

====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|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 size]]s of significant findings were generally small. One review concluded that, although most cognitive faculties were unimpaired by cannabis use, residual deficits occurred in [[executive function]]s. 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]] 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 [[Cannabis and memory|memory and cognition problems]], risk of addiction, and the risk of [[schizophrenia]] in young people.

<div lang="en" dir="ltr" class="mw-content-ltr">

====Neuroimaging====

Although global abnormalities in [[white matter]] and [[grey matter]] are not consistently associated with cannabis use, reduced [[hippocampus|hippocampal]] volume is consistently found. [[Amygdala]] 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]], which is thought to reflect compensatory activity due to reduced processing efficiency. Cannabis use is also associated with downregulation of [[Cannabinoid receptor type 1|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]] metabolites in the human brain.

<div lang="en" dir="ltr" class="mw-content-ltr">

===Cannabis dependence===

{{Main|Cannabis dependence}}

About 9% of those who experiment with marijuana eventually become dependent according to [[Diagnostic and Statistical Manual of Mental Disorders|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, [[Deviance (sociology)|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-5]] criteria, 9% of those who are exposed to cannabis develop cannabis use disorder, compared to 20% for [[cocaine]], 23% for [[alcohol (drug)|alcohol]] and 68% for [[nicotine]]. Cannabis use disorder in the DSM-5 involves a combination of DSM-IV criteria for cannabis abuse and dependence, plus the addition of craving, without the criterion related to legal troubles.

<div lang="en" dir="ltr" class="mw-content-ltr">

====Psychiatric====

{{See also|Long-term effects of cannabis#Mental health}}

At an epidemiological level, a [[dose–response relationship]] 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.

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]]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 [[alcoholism|problematic drinking]] was premature without further study. Various surveys conducted between 2015 and 2019 found that many users of cannabis substitute it for [[prescription drug]]s (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]] (CHS) is a severe condition seen in some chronic cannabis users where they have repeated bouts of uncontrollable vomiting for 24–48 hours.

A limited number of studies have examined the [[Cannabis-associated respiratory disease|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]]. Other side effects of cannabis use include [[cannabinoid hyperemesis syndrome]] (CHS), a condition which involves recurrent nausea, cramping abdominal pain, and vomiting.

Cannabis smoke contains thousands of organic and inorganic chemical compounds. This [[tar (tobacco residue)|tar]] is chemically similar to that found in tobacco smoke, and over fifty known [[carcinogen]]s have been identified in cannabis smoke, Cannabis smoke is also inhaled more deeply than tobacco smoke. {{as of|2015}}, 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]]s (TGCTs), particularly non-[[seminoma]] 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 (inhalation device)|vaporizer]], consuming THC in pill form, or consuming [[cannabis foods]].

There is concern that cannabis may contribute to cardiovascular disease, but {{as of|2018|lc=y}}, 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]] properties of prescription drugs used for [[thrombosis|treating blood clots]]. {{as of|2019}}, the [[Mechanism of action|mechanisms]] for the [[anti-inflammatory]] and possible [[Analgesic|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 [[Long-term effects of cannabis#Mental health|acute psychiatric effects]], primarily [[suicidal ideation]], depression, and anxiety. An additional third of the cases were for gastrointestinal issues including [[cannabinoid hyperemesis syndrome]].

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.

<div lang="en" dir="ltr" class="mw-content-ltr">

====Reproductive health====

{{excerpt|Cannabis in pregnancy|paragraph=1}}

===Secondhand cannabis smoke===

A 2022 study found that smoking cannabis using a bong can greatly increase background levels of [[Particulates|fine particulate matter]], a [[carcinogen]], in an enclosed space such as a living room. After 15 minutes, mean levels of particulate matter were more than twice the [[United States Environmental Protection Agency|Environmental Protection Agency]] hazardous air quality threshold, and after 140 minutes, the concentrations were four times greater than those generated by smoking tobacco using a cigarette or [[hookah]]. This suggests secondhand cannabis smoke from bongs may present a health risk to non-smokers.

<div lang="en" dir="ltr" class="mw-content-ltr">

==Pharmacology==