Cannabis: Difference between revisions

| images           = [[File:Cannabis_sativa_plant.JPG|frameless|260px|alt=A mature Cannabis sativa plant in the field, photographed by Chmee2, 2010, CC BY-SA 3.0]]<br><small>''Cannabis sativa'' &middot; photo: Chmee2, [https://creativecommons.org/licenses/by-sa/3.0/ CC BY-SA 3.0]</small>

| binomial        = Cannabis sativa

| family          = Cannabaceae

| common_names    = hemp, marijuana, bhang, ganja, hashish, weed

| native_range    = Central Asia

| parts_used      = flowering tops, leaves, seeds, fiber

| interactionsummary =

| pharmacokinetics =

| pharmacodynamics =

| intro           = Some time in the fourth century BC, a young woman was buried near what is now Turpan, in far western China, and laid out beneath a shroud of thirteen whole cannabis plants, their roots gathered at her pelvis and their tops fanned across her chest.<ref name="jiang2016">Jiang H, Wang L, Merlin MD, et al. Ancient Cannabis Burial Shroud in a Central Eurasian Cemetery. ''Economic Botany''. 2016 Sep;70(3):213-221. DOI: 10.1007/s12231-016-9351-1.</ref> She was one of countless people, across at least three thousand years, for whom this plant was worth carrying into the grave. The history of cannabis is older than almost any other medicine, and it is bound up from the beginning with ritual, with healing, with intoxication, and, in its most recent and strangest chapter, with prohibition.

| traditional_uses = Cannabis may be among the first plants that human beings ever cultivated. It grew readily on the disturbed ground around early settlements, and it offered three distinct gifts at once: a strong fiber, an oil-rich and edible seed, and a resin that altered the mind. Which of these was wanted first cannot now be known.

The earliest physical traces are of the fiber: cord-marked pottery from Taiwan has been dated to around the sixth millennium BC, and the use of hemp for cloth and rope is documented across early China. The plant's medicinal use is recorded in the Chinese tradition by the first centuries of the common era, where it was gathered into the body of plant knowledge attributed to the legendary herbalist Shennong; that tradition valued cannabis as a remedy while also warning that taken to excess it could disorder the mind. In India, cannabis enters the written record in the ''Atharvaveda'', which names it among a small number of sacred plants said to release anxiety, and it became woven permanently into devotional life, associated above all with the god Shiva and consumed as the milk-and-cannabis preparation called bhang.

To the north and west, the plant belonged to the Scythians, the horse peoples of the Eurasian steppe. In the fifth century BC the Greek historian Herodotus described how the Scythians would sit inside a small closed tent, throw cannabis onto heated stones, and inhale the rising smoke until they "shouted aloud" with exhilaration. For a long time this was read as travelers' embroidery, until archaeology bore it out: excavations of steppe burial mounds, and of the frozen tombs of the Altai mountains, have repeatedly turned up cannabis seeds, charred residues, and the small braziers Herodotus described.<ref name="ren2019">Ren M, Tang Z, Wu X, et al. The origins of cannabis smoking: Chemical residue evidence from the first millennium BCE in the Pamirs. ''Science Advances''. 2019 Jun 12;5(6):eaaw1391. PMID: 31206023.</ref> The plant was, for these cultures, both a funerary offering and a means of reaching an altered state.

Cannabis spread along the trade routes of the medieval Islamic world, where its resin, hashish, was widely used despite an uneasy and shifting relationship with religious and legal authority. The Persian physician Avicenna discussed it in his medical writing, and the drug attached itself to one of the most durable legends of the period, the story linking the word "hashish" to the sect known to Crusader chroniclers as the Assassins, a tale far more legend than history but one that fixed cannabis in the European imagination for centuries.

Cannabis entered modern Western medicine through a single decisive figure. In the late 1830s an Irish physician, William Brooke O'Shaughnessy, working in Calcutta, studied the Indian medical use of the plant, experimented with cannabis preparations on patients, and published accounts that introduced it to British and then American doctors.<ref name="oshaughnessy1843">O'Shaughnessy WB. On the Preparations of the Indian Hemp, or Gunjah. ''Provincial Medical Journal and Retrospect of the Medical Sciences''. 1843;5(123):363-369.</ref> Within a decade cannabis extracts were a normal part of the Western pharmacy: it was listed in the United States Pharmacopeia from 1850, and was prescribed for pain, for spasm, for sleeplessness, and for a wide range of other complaints. In 1894 the British government's Indian Hemp Drugs Commission, after an extensive inquiry, concluded that moderate use of the drug produced no significant harm, a finding strikingly at odds with the panic that would follow.

That panic defines the plant's twentieth century. In the United States, cannabis prohibition grew less from medicine than from social fear: the drug was associated, in press and in political rhetoric, with Mexican immigrants and Black musicians, and a campaign of lurid newspaper stories tied it to insanity and violence. The newly created Federal Bureau of Narcotics, under its first commissioner Harry Anslinger, made cannabis a central target. The Marihuana Tax Act of 1937 effectively ended the drug's legal medical use in the United States, over the formal objection of the American Medical Association; cannabis was dropped from the United States Pharmacopeia in 1942. Through the international drug-control treaties of the following decades and the United States Controlled Substances Act of 1970, which placed cannabis in the most restrictive category, prohibition became near-global.

| quote  = The laws against marijuana use have a great deal more to do with racism and religious bigotry than with public health.

The most recent chapter is a slow reversal. Beginning with California's legalization of medical use in 1996, a steadily growing number of jurisdictions have re-permitted cannabis for medical and then for recreational use; Uruguay in 2013 and Canada in 2018 legalized it nationally, and many United States states have done so even as it remains federally prohibited, a dissonance still unresolved. In 2018 the first cannabis-derived medicine, a purified cannabidiol preparation, was approved by the United States Food and Drug Administration for rare forms of epilepsy. After a century of prohibition, cannabis is once again, unevenly and contentiously, a medicine.

| botany          = Cannabis is an annual flowering plant of the family Cannabaceae, the small plant family it shares with the hop. It is typically dioecious, meaning individual plants are either male or female, though plants that carry both sexes occur. The resin that carries the plant's psychoactive compounds is produced most densely by the unfertilized flowering tops of female plants, in tiny stalked glands called trichomes. Whether the genus contains a single variable species or several, most often named ''Cannabis sativa'', ''Cannabis indica'', and ''Cannabis ruderalis'', has been debated by botanists for two centuries and is still not settled; the names ''sativa'' and ''indica'' as used in commerce do not reliably correspond to the botanical distinctions.

| quote  = Cannabis may be mankind's first cultivated plant, but it has never lost its wildness.

| constituents    = Cannabis produces a large family of characteristic compounds known as cannabinoids, of which two are most significant. [[THC|Tetrahydrocannabinol]] (THC) is the principal psychoactive constituent, responsible for most of the intoxicating effect; it was first isolated and characterized in 1964 by the Israeli chemists Yechiel Gaoni and Raphael Mechoulam.<ref name="gaoni1964">Gaoni Y, Mechoulam R. Isolation, Structure, and Partial Synthesis of an Active Constituent of Hashish. ''Journal of the American Chemical Society''. 1964;86(8):1646-1647. DOI: 10.1021/ja01062a046.</ref> [[Cannabidiol|Cannabidiol]] (CBD) is a second major cannabinoid that is not intoxicating in the way THC is, and which has attracted significant medical interest in its own right. The plant also yields smaller quantities of other cannabinoids, among them [[CBN|cannabinol]] (CBN), a breakdown product of THC, and [[CBG|cannabigerol]] (CBG). The relative proportions of these compounds vary widely between plants.

| preparations    = Cannabis has been prepared and consumed in many forms across its history. The dried flowering tops and leaves are the most familiar form. Hashish, long associated with the cultures of the Middle East, North Africa, and South Asia, is the separated and compressed resin of the plant. In the Indian tradition, bhang is a drink combining ground cannabis with milk and spices. The plant's seeds yield a nutritious oil, and its stalk yields the fiber used for millennia to make rope and cloth, a use entirely separate from any psychoactive purpose.

| pharmacodynamics = The cannabinoids act on the body through what is now called the endocannabinoid system, a signalling system of receptors and naturally occurring molecules that was discovered, in the late twentieth century, precisely through the effort to understand how cannabis works. THC is understood to act chiefly as a partial agonist at the receptor known as CB1, which is abundant in the brain, and this action is understood to underlie most of its psychoactive effects. The body produces its own molecules that act on these same receptors, the first of which, anandamide, was identified in 1992.<ref name="devane1992">Devane WA, Hanus L, Breuer A, et al. Isolation and structure of a brain constituent that binds to the cannabinoid receptor. ''Science''. 1992 Dec 18;258(5090):1946-1949. PMID: 1470919.</ref> That these receptors and molecules exist is well established; the full account of what the endocannabinoid system does, and of how cannabis produces its more complex effects, remains an active area of research.

| effects          = The effects of cannabis are dose-dependent, vary considerably between individuals and between preparations, and depend heavily on the setting and the expectations of the user. Commonly reported effects include euphoria, relaxation, an altered sense of time, increased appetite, a heightening of the senses, and a tendency for thought to move associatively. The experience can also include anxiety, and at higher doses acute distress or transient perceptual disturbance.

| counseling      = Cannabis has a notably low risk of fatal overdose: there is no well-established lethal dose, and death from cannabis toxicity alone is, on the available evidence, exceedingly rare. This does not mean its use is without risk. Regular heavy use can lead to cannabis use disorder, a recognized form of dependence with a withdrawal syndrome. The most serious and most debated concern is psychiatric: cannabis use, particularly heavy use, particularly of high-potency preparations, and particularly beginning in adolescence, is associated in a substantial body of research with an increased risk of psychotic illness, and is recognized as especially inadvisable for people with a personal or family history of psychosis.<ref name="marconi2016">Marconi A, Di Forti M, Lewis CM, Murray RM, Vassos E. Meta-analysis of the Association Between the Level of Cannabis Use and Risk of Psychosis. ''Schizophrenia Bulletin''. 2016 Sep;42(5):1262-1269. PMID: 26884547.</ref> Smoking cannabis exposes the lungs to combustion products and can contribute to respiratory symptoms. Cannabis can acutely impair coordination, judgment, and reaction time, which matters for driving. As with all medicines, figures for these risks are population estimates that vary between studies, and individual response varies considerably between people.

| quote  = '''in its natural form''', one of the safest therapeutically active substances known to man

| volume  = Poeia

| page    = 196

| source = Francis Young, US DEA Administrative Law Judge, 1988

| anecdotes       = {{PendellsCorner

| quote  = The Cannabis ally has a way of pretending that she's not doing anything. ... Experienced ganja smokers adjust and lead quite ordinary-looking and often successful lives. ... Some of them get high every day. But just as tobacco and heroin habitues need their ally to feel normal, so the hemp smoker can confuse his intoxication for the ground state — a mistake the doctor of our lineage ought never make.

| seealso         = [[THC]], [[CBD]], [[CBN]], [[CBG]], [[THCV]], [[Dronabinol]], [[Nabilone]], [[Nabiximols]], [[Cannabidiol]], [[:Category:Cannabinoids|Cannabinoids]]

| references       = <references/>