Psilocybin mushrooms, commonly known as magic mushrooms or shrooms, are a polyphyletic, informal group of fungi that contain psilocybin which turns into psilocin. Biological genera containing psilocybin mushrooms include Copelandia, Gymnopilus, Inocybe, Panaeolus, Pholiotina, Pluteus, and Psilocybe. Psilocybin mushrooms have been and continue to be used in indigenous New World cultures in religious, divinatory, or spiritual contexts. They may be depicted in Stone Age rock art in Africa and Europe, but are most famously represented in the Pre-Columbian sculptures and glyphs seen throughout North, Central and South America.
The hallucinogenic species of the Psilocybe genus have a history of use among the native peoples of Mesoamerica for religious communion, divination, and healing, from pre-Columbian times to the present day. Mushroom stones and motifs have been found in Guatemala. A statuette dating from ca. 200 CE. depicting a mushroom strongly resembling Psilocybe mexicana was found in the west Mexican state of Colima in a shaft and chamber tomb. A Psilocybe species known to the Aztecs as teōnanācatl (literally "divine mushroom" - agglutinative form of teōtl (god, sacred) and nanācatl (mushroom) in Náhuatl) was reportedly served at the coronation of the Aztec ruler Moctezuma II in 1502. Aztecs and Mazatecs referred to psilocybin mushrooms as genius mushrooms, divinatory mushrooms, and wondrous mushrooms, when translated into English. Bernardino de Sahagún reported the ritualistic use of teonanácatl by the Aztecs when he traveled to Central America after the expion of Hernán Cortés.
After the Spanish conquest, Catholic missionaries campaigned against the cultural tradition of the Aztecs, dismissing the Aztecs as idolaters, and the use of hallucinogenic plants and mushrooms, together with other pre-Christian traditions, was quickly suppressed. The Spanish believed the mushroom allowed the Aztecs and others to communicate with demons. Despite this history the use of teonanácatl has persisted in some remote areas .
The first mention of hallucinogenic mushrooms in European medicinal literature was in the London Medical and Physical Journal in 1799: a man served Psilocybe semilanceata mushrooms he had picked for breakfast in London's Green Park to his family. The doctor who treated them later described how the youngest child "was attacked with fits of immoderate laughter, nor could the threats of his father or mother refrain him."
In 1955, Valentina Pavlovna Wasson and R. Gordon Wasson became the first known European Americans to actively participate in an indigenous mushroom ceremony. The Wassons did much to publicize their experience, even publishing an article on their experiences in Life on May 13, 1957. In 1956 Roger Heim identified the psychoactive mushroom the Wassons brought back from Mexico as Psilocybe, and in 1958, Albert Hofmann first identified psilocybin and psilocin as the active compounds in these mushrooms.
Inspired by the Wassons' Life article, Timothy Leary traveled to Mexico to experience psilocybin mushrooms himself. When he returned to Harvard in 1960, he and Richard Alpert started the Harvard Psilocybin Project, promoting psychological and religious study of psilocybin and other psychedelic drugs. After Leary and Alpert were dismissed by Harvard in 1963, they turned their attention toward promoting the psychedelic experience to the nascent hippie counterculture.
The popularization of entheogens by the Wassons, Leary, Terence McKenna, Robert Anton Wilson and many others led to an explosion in the use of psilocybin mushrooms throughout the world. By the early 1970s, many psilocybin mushroom species were described from temperate North America, Europe, and Asia and were widely collected. Books describing methods of cultivating large quantities of Psilocybe cubensis in were also published. The availability of psilocybin mushrooms from wild and cultivated sources have made them one of the most widely used of the psychedelic drugs.
At present, psilocybin mushroom use has been reported among some groups spanning from central Mexico to Oaxaca, including groups of Nahua, Mixtecs, Mixe, Mazatecs, Zapotecs, and others. An important figure of mushroom usage in Mexico was María Sabina, who used native mushrooms, such as Psilocybe mexicana in her practice.
Present in varying concentrations in about 200 species of Basidiomycota mushrooms, psilocybin evolved from its ancestor, muscarine, some 10 to 20 million years ago. In a 2000 review on the worldwide distribution of psilocybin mushrooms, Gastón Guzmán and colleagues considered these distributed among the following genera: Psilocybe (116 species), Gymnopilus (14), Panaeolus (13), Copelandia (12), Pluteus (6) Inocybe (6), Pholiotina (4) and Galerina (1). Guzmán increased his estimate of the number of psilocybin-containing Psilocybe to 144 species in a 2005 review.
Many of them are found in Mexico (53 species), with the remainder distributed throughout Canada and the US (22), Europe (16), Asia (15), Africa (4), and Australia and associated islands (19). Generally, psilocybin-containing species are dark-spored, gilled mushrooms that grow in meadows and woods in the subtropics and tropics, usually in soils rich in humus and plant debris. Psilocybin mushrooms occur on all continents, but the majority of species are found in subtropical humid forests. P. cubensis is the most common Psilocybe in tropical areas. P. semilanceata, considered the world's most widely distributed psilocybin mushroom, is found in temperate parts of Europe, North America, Asia, South America, Australia and New Zealand, although it is absent from Mexico.
The effects of psilocybin mushrooms come from psilocybin and psilocin. When psilocybin is ingested, it is broken down by the liver in a process called dephosphorylation. The resulting compound is called psilocin, which is responsible for the psychedelic effects. Psilocybin and psilocin create short-term increases in tolerance of users, thus making it difficult to misuse them because the more often they are taken within a short period of time, the weaker the resultant effects are. Psilocybin mushrooms have not been known to cause physical or psychological dependence (addiction). The psychedelic effects tend to appear around 20 minutes after ingestion and can last up to 6 hours. Physical effects including nausea, vomiting, euphoria, muscle weakness or relaxation, drowsiness, and lack of coordination may occur.
As with many psychedelic substances, the effects of psychedelic mushrooms are subjective and can vary considerably among individual users. The mind-altering effects of psilocybin-containing mushrooms typically last from three to eight hours depending on dosage, preparation method, and personal metabolism. The first 3–4 hours after ingestion are typically referred to as the 'peak'—in which the user experiences more vivid visuals and distortions in reality. The effects can seem to last much longer to the user because of psilocybin's ability to alter time perception.
Sensory effects include visual and auditory hallucinations followed by emotional changes and altered perception of time and space. Noticeable changes to the auditory, visual, and tactile senses may become apparent around 30 minutes to an hour after ingestion, although effects may take up to two hours to take place. These shifts in perception visually include enhancement and contrasting of colors, strange light phenomena (such as auras or "halos" around light sources), increased visual acuity, surfaces that seem to ripple, shimmer, or breathe; complex open and closed eye visuals of form constants or images, objects that warp, morph, or change solid colours; a sense of melting into the environment, and trails behind moving objects. Sounds may seem to have increased clarity—music, for example, can take on a profound sense of cadence and depth. Some users experience synesthesia, wherein they perceive, for example, a visualization of color upon hearing a particular sound.
As with other psychedelics such as LSD, the experience, or 'trip', is strongly dependent upon set and setting. Hilarity, depression, lack of concentration, and muscular relaxation (including dilated pupils) are all normal effects, sometimes in the same trip. A negative environment could contribute to a bad trip, whereas a comfortable and familiar environment would set the stage for a pleasant experience. Psychedelics make experiences more intense, so if a person enters a trip in an anxious state of mind, they will likely experience heightened anxiety on their trip. Many users find it preferable to ingest the mushrooms with friends or people who are familiar with 'tripping'. The psychological consequences of psilocybin use include hallucinations and an inability to discern fantasy from reality. Panic reactions and psychosis also may occur, particularly if a user ingests a large dose. In addition to the risks associated with ingestion of psilocybin, individuals who seek to use psilocybin mushrooms also risk poisoning if one of the many varieties of poisonous mushrooms is confused with a psilocybin mushroom.
A study at Johns Hopkins University found that a dose of 20 to 30 mg psilocybin per 70 kg occasioning mystical-type experiences brought lasting positive changes to traits including altruism, gratitude, forgiveness and feeling close to others when it was combined with mation and an extensive spiritual practice support programme. There is scientific evidence for a context- and state-dependent causal effect of psychedelic use on connection with nature.
Dosage of mushrooms containing psilocybin depends on the psilocybin and psilocin content of the mushroom which can vary significantly between and within the same species, but is typically around 0.5–2.0% of the dried weight of the mushroom. Usual doses of the common species Psilocybe cubensis range around 1.0 to 2.5 g, while about 2.5 to 5.0 g dried mushroom material is considered a strong dose. Above 5 g is often considered a heavy dose with 5.0 grams of dried mushroom often being referred to as a "heroic dose".
The concentration of active psilocybin mushroom compounds varies from species to species, but also from mushroom to mushroom within a given species, subspecies or variety. The same holds true for different parts of the same mushroom. In the species Psilocybe samuiensis, the dried cap of the mushroom contains the most psilocybin at about 0.23%–0.90%. The mycelium contains about 0.24%–0.32%.
Psilocybin has been a subject of preliminary research since the early 1960s, for instance 1962 in the Marsh Chapel Experiment. After 1970, because of the Controlled Substances Act the research had been frozen for decades before mushrooms were tested again for their potential to treat drug dependence, anxiety or mood disorders. In 2019, Michael Pollan said to the World Science Festival: "That’s a remarkable event in the history of science. I don’t know that you can point to another time or episode where you had a very promising line of inquiry that is simply stopped for reasons that have nothing to do with the science. And we lost 30 years of research. Imagine what we would know now had we been studying these compounds for those 30 years. What we might’ve learned about depression, anxiety and addiction, consciousness and how the mind works."
In 2018 the Food and Drug Administration (FDA) granted Breakthrough Therapy Designation for psilocybin-assisted therapy for treatment-resistant depression. In 2019, the FDA granted Breakthrough Therapy Designation for psilocybin therapy treating major depressive disorder.
Psilocybin mushrooms are regulated or prohibited in many countries, often carrying severe legal penalties (for example, the US Psychotropic Substances Act, the UK Misuse of Drugs Act 1971 and Drugs Act 2005, and in Canada the Controlled Drugs and Substances Act).
A State on whose territory there are plants growing wild which contain psychotropic substances from among those in Schedule I and which are traditionally used by certain small, clearly determined groups in magical or religious rites, may, at the time of signature, ratification or accession, make reservations concerning these plants, in respect of the provisions of article 7, except for the provisions relating to international trade.
However, this exemption would apply only if the plant were ever explicitly added to the Schedules of the Psychotropic Convention. Currently the Convention applies only to chemicals. The Commentary on the Convention on Psychotropic Substances notes, however, that the plants containing it are not subject to international control:
The cultivation of plants from which psychotropic substances are obtained is not controlled by the Vienna Convention .... Neither the crown (fruit, mescal button) of the Peyote cactus nor the roots of the plant Mimosa hostilis nor Psilocybe mushrooms themselves are included in Schedule 1, but only their respective principals, mescaline, DMT, and psilocin.
No plants (natural materials) containing DMT are at present controlled under the 1971 Convention on Psychotropic Substances. Consequently, preparations (e.g. decoctions) made of these plants, including ayahuasca are not under international control and, therefore, not subject to any of the articles of the 1971 Convention. -- International Narcotics Control Board (INCB), United Nations
Mushroom spores do not contain psilocybin, and therefore are not included in this prohibition.
Psychoactive mushrooms in their fresh form are legal in Austria.
On November 29, 2008, the Netherlands announced it would ban the cultivation and use of most psilocybin-containing fungi beginning December 1, 2008. While several sorts of mushrooms – most notably the less-strong "truffles" – were probably by omission not placed on the ban list, some [smart shops] continue their sale. Since September 13, 2019, magic truffels are fully taxed and legalized.
Dried mushrooms are classified as illegal, as they are considered a psilocybin-containing preparation.
The UK ban on fresh mushrooms introduced in 2005 came under much criticism, but was rushed through at the end of the 2001-2005 Parliament; until then, magic mushrooms were sold in the UK.
The US Drug Enforcement Administration places psilocybin among Schedule I drugs in the Controlled Substances Act having a high potential for abuse, no approved medical uses, and having potential to cause severe side effects or poisoning.
New Mexico appeals court ruled on June 14, 2005, that growing psilocybin mushrooms for personal consumption could not be considered "manufacturing a controlled substance" under state law. However, it still remains illegal under federal law. In December 2018, Oregon's Secretary of State approved a ballot initiative that would make psychedelic mushrooms legal among licensed therapists.
In May 2019, Denver, Colorado, became the first city in the United States to decriminalize psilocybin mushrooms after an ordinance was admitted to the ballot, and narrowly won with 50.6% of the vote. The initiative did not actually legalize mushrooms, but does prohibit Denver from spending any resources to prosecute people for their use or possession. The law applies to adults over the age of 18, and psilocybin remains illegal in Colorado. In June 2019, Oakland became the second US city, in January 2020, Santa Cruz the third, and in September 2020, Ann Arbor, Michigan, the fourth US city to decriminalize psilocybin mushrooms by passing resolutions to end criminal penalties for use and possession of psilocybin. In November 2020, the state of Oregon became the first U.S. state to both decriminalize psilocybin and also legalize it for therapeutic use.
Portugal decriminalized possession of all recreational drugs (including psilocybin mushrooms) in quantities no more than a ten-day supply of that substance. However cultivation and distribution (buying/selling) are a criminal offence.
Psilocybin is illegal in India. However, enforcement of this prohibition is complicated by the fact that while the compound itself is banned, mushrooms containing the substance are not.
Psilocybin is legal in Jamaica. People wanting to try psilocybin in a legal setting can purchase vacation packages including on-site therapists and doctors who monitor participants who have taken the psychedelic drug.
The mushroom remains a federal Schedule 1 controlled substance, prohibited under state and federal law