Psilocybe mexicana is a moderately potent hallucinogen due to the presence of both psilocybin (4-phosphoryloxy-N,N-dimethyltryptamine) and its biologically active form, psilocin (4-hydroxy-N,N-dimethyltryptamine), in the species’ fruiting bodies. Although the percentage of psilocybin and psilocin in a given P. mexicana sample varies with growing conditions, Heim and Hoffman detected 0.25% psilocybin and 0.15% psilocin in the sample used for the species’s diagnostic description (Stamets 130). Upon introduction to the body, psilocybin is rapidly converted to psilocin through a dephosphorylation reaction (Horita and Weber 32-33). Psilocin subsequently acts as a partial agonist at the 5-HT2A serotonin receptor and as an agonist at the 5-HT1A and 5-HT2A/2C serotonin receptors (Passie et al. 362). “The effects of psilocybin, which appear within 20 minutes of ingestion, last approximately 6 hours. Although the effects experienced by Psilocybe species users vary depending on the individual, the active compounds in psilocybin-containing ‘magic’ mushrooms have LSD-like properties and produce alterations of autonomic function, motor reflexes, behavior, and perception. The psychological consequences of psilocybin use include hallucinations, an altered perception of time, and an inability to discern fantasy from reality. Panic reactions and psychosis also may occur, particularly if a user ingests a large dose. Long-term effects such as flashbacks, risk of psychiatric illness, impaired memory, and tolerance have been described in case reports.Other effects may include muscle relaxation or weakness, ataxia, excessive pupil dilation, nausea, vomiting, and drowsiness” (“NIDA…”). Due to its hallucinogenic effects, many Psilocybe species, including P. mexicana, are ingested recreationally. According to the National Institute on Drug Abuse, mushrooms containing psilocybin are commercially available both fresh or dried and are typically taken orally. Since psilocybin and psilocin cannot be inactivated by cooking or freezing preparations, they may also be brewed as a tea or added to other foods to mask their bitter flavor. Furthermore, due to the relative difficulty of identifying mushroom species without significant identification experience, individuals who ingest psilocybin mushrooms recreationally also risk poisoning if one of many existing varieties of poisonous mushrooms is incorrectly identified as a psilocybin mushroom. Although it is difficult to gauge the extent of use of hallucinogens such as psilocybin and peyote because most data sources that quantify drug use exclude these drugs, “the Monitoring the Future survey reported in 2008 that 7.8 percent of high school seniors had used hallucinogens other than LSD—a group that includes peyote, psilocybin, and others—at least once in their lifetime. Past-year use was reported to be 5.0 percent” (“NIDA…”).
Although the recreational use of Psilocybin species often calls to mind the “psychedelic underground- of hippies, freaks, and travelers,” so-called “magic mushrooms” have been used for at least hundreds, perhaps thousands, of years by indigenous civilizations around the world, particularly those of Mexico (Letcher 3). Anthropological research has indicated that “at the time of the Spanish invasion, psychoactive mushrooms were being consumed in a variety of religious, secular, recreation, and even diplomatic contexts within the dominant Mesoamerican Aztec civilization” (Letcher 76). However, the portrayal of mushrooms in pre-Columbian, Mesoamerican art and codices suggests that the use of psychoactive mushrooms predates the Spanish conquest. For example, the Codex Vindobonensis (the Vienna Codex), a Mixtec work depicting the origins of the world, depicts several gods and goddesses clutching or eating mushrooms (Letcher 76-77). After the arrival of the Spanish, however, indigenous peoples often integrated practices derived from Catholicism with Mesoamerican sprititual practices, therefore creating syncretic religious traditions that continued to emphasize the role of psychoactive mushroom consumption in the religious experience. In 1929, an anthropological expedition to Mexico led by Richard Evans Schultes observed the syncretism evident in a specific Mazatec religious tradition, cited in this article as an example of post-Columbian ritualistic use of psychoactive mushrooms. According to records from this expedition, the Mazatec brujo (roughly translated as wizard, but with the connotation of shaman) eats three mushrooms at the beginning of the ritual and prays to the Holy Trinity as well as to native elemental powers including the earth, stars, moon, and sun. Regarding the role of the mushroom in this practice, the Mazatec teach that while under the influence of the mushroom, it is the mushroom that speaks rather than the brujo. Although many species of hallucinogenic mushrooms, particularly Psilocybe species, occur naturally in Mexico, Psilocybe mexicana, often called di-nize or tsamikindi in the Mazatec language, is one of three species of mushrooms used in Mazatec ritualistic practice (Akers 9). Psychoactive mushrooms including Psilocybe species, called teonanacatl in the Aztec language, Nahuatl, are used ritually in Central Mexico to this day.
For a more complete history of human interaction with Psilocybe species, whether accidental, recreational, or ritualistic, refer to Andy Letcher’s Shroom: A Cultural History of the Magic Mushroom (see “References” section for full citation details).
Despite its frequent association with both recreational and Mesoamerican ritualistic use, psilocybin-containing mushroom species also offer potential medicinal value. For example, administration of psilocybin is being assessed in both Phase I and Phase II double-blind, placebo-controlled pilot studies for its potential to alleviate anxiety associated with advanced or potentially life-threatening cancer. Furthermore, the study is also investigating “the effect of psilocybin on symptoms of pain perception, depression, existential/psychospiritual distress, attitudes towards disease progression and death, quality of life, and spiritual/mystical states of consciousness.” The study hypothesizes that “a one time experience with psilocybin will occasion dramatic shifts in consciousness and awareness that will lead to short-term (ie hours to days) and long-term (up to 6 months in this study, following the administration of the second dosing, either psilocybin or placebo) improvement in anxiety, depression, and pain associated with advanced cancer” (“Psilocybin Advanced…”). In addition, another study is investigating if “psilocybin can produce personally and spiritually meaningful experiences in cancer patients,” which would represent a valuable medical intervention since “spirituality has been associated with increased psychological coping and decreased depression in serious illness” (“Psychopharmacology…”).