LSD | 定義、心理的影響、エルゴット菌

LSD | Definition, Psychological Effects, & Ergot Fungus | Britannica Ask the Chatbot Games & Quizzes History & Society Science & Tech Biographies Animals & Nature Geography & Travel Arts & Culture ProCon Money Videos LSD Introduction References & Edit History Quick Facts & Related Topics Images At a Glance LSD summary Contents CITE verified Cite While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions. Select Citation Style MLA APA Chicago Manual of Style Copy Citation Share Share Share to social media Facebook X URL https://www.britannica.com/science/LSD Feedback External Websites Feedback Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login). Feedback Type Select a type (Required) Factual Correction Spelling/Grammar Correction Link Correction Additional Information Other Your Feedback Submit Feedback Thank you for your feedback Our editors will review what you’ve submitted and determine whether to revise the article. External Websites Healthdirect - LSD (acid) Verywell Mind - The History of Acid or LSD Frontiers - Frontiers in Psychiatry - Therapeutic Use of LSD in Psychiatry: A Systematic Review of Randomized-Controlled Clinical Trials WebMD - What is LSD? Healthline - Everything You Need to Know About LSD National Center for Biotechnology Information - PubMed Central - The Pharmacology of Lysergic Acid Diethylamide: A Review Nature - Modern Clinical Research on LSD CellPress - Current Biology - Hallucinogenic Drugs: A New Study Answers Old Questions about LSD Alcohol and Drug Foundation - LSD LSD drug Ask Anything Homework Help Also known as: d-lysergic acid diethylamide, lysergic acid d iethylamide, lysergide (Show More) Written by John Philip Jenkins Distinguished Professor of History, Baylor University. Author of A History of the United States , Mystics and Messiahs: Cults and New Religions in America , Synthetic Panics: The Symbolic... John Philip Jenkins Fact-checked by Britannica Editors Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree.... Britannica Editors Last updated Mar. 23, 2026 • History Britannica AI Ask Anything Table of Contents Table of Contents Ask Anything LSD , potent synthetic hallucinogenic drug that can be derived from the ergot alkaloids (as ergotamine and ergonovine , principal constituents of ergot, the grain deformity and toxic infectant of flour caused by the fungus Claviceps purpurea ). LSD is usually prepared by chemical synthesis in a laboratory. Its basic chemical structure is similar to that of the ergot alkaloids, and it is structurally related to several other drugs (e.g., bufotenine , psilocybin , harmine , and ibogaine ), which can all block the action of serotonin (the indole amine transmitter of nerve impulses) in brain tissue. LSD produces marked deviations from normal behaviour, probably the consequence of its ability to inhibit the action of serotonin, though the mechanism of the drug remains uncertain. LSD was used experimentally in medicine as a psychotomimetic agent to induce mental states that were believed to resemble those of actual psychotic diseases (primarily the schizophrenias ). After administration, LSD can be absorbed readily from any mucosal surface—even the ear —and acts within 30 to 60 minutes. Its effects usually last for 8 to 10 hours, and occasionally some effects persist for several days. Two serious side effects are the prolongation and transient reappearance of the psychotic reaction. Since LSD is not an approved drug, its therapeutic applications are regarded as experimental. In the 1960s LSD was proposed for use in the treatment of neuroses , especially for patients who were recalcitrant to more conventional psychotherapeutic procedures. LSD also was tried as a treatment for alcoholism and to reduce the suffering of terminally ill cancer patients. It was studied as an adjunct in the treatment of narcotic addiction , of children with autism , and of the so-called psychopathic personality. None of those uses were successful by the early 1990s, and most researchers concluded that there was no clinical value in the use of LSD. In the early 21st century, however, research into the treatment of alcoholism with LSD was revived, some researchers concluding that it might provide benefits. There was also interest in the use of LSD to relieve anxiety in patients suffering from terminal illness. The use of LSD outside a clinical setting can be dangerous. Mood shifts, time and space distortions, and impulsive behaviour are especially hazardous complications to an individual who takes the drug. The individual may become increasingly suspicious of the intentions and motives of those around him and may act aggressively against them. Legitimate use of LSD declined markedly in the mid-1960s. In the United States , manufacture, possession, sale, transfer, and use of LSD came under the restrictions of the Drug Abuse Control Amendment of 1965. The following year the only authorized manufacturer of LSD in the United States withdrew the drug from the market and transferred its supplies to the federal government. Research projects continued under the supervision of the National Institute of Mental Health, a governmental agency. During the 1960s LSD (“acid”) became popular within the hippie subculture that emerged in the United States and western Europe . One critical pioneer in that movement was Augustus Owsley Stanley III, a California-based underground chemist who manufactured several million doses of the drug. Stanley’s efforts supplied the drug to several figures who would become advocates for LSD, including novelist Ken Kesey . Stanley also was a personal supplier of LSD to the Grateful Dead (for whom he also provided early financial support and served as sound engineer). Another major advocate of LSD was American psychologist Timothy Leary . Abbreviation of: lysergic acid diethylamide (Show more) Also called: lysergide (Show more) Key People: Albert Hofmann Timothy Leary (Show more) Related Topics: drug use hallucinogen psychedelic rock Today in History—April 19: The Very First Acid Trip in History Schedule I drug (Show more) See all related content During the mid-1960s, use of LSD spread widely in the emerging counterculture, and the shapes and colours characteristic of LSD-induced trips appear frequently in the visual art of the period. The drug also powerfully shaped the popular music of the 1960s and encouraged the mystical experimentation of those years. LSD retained a youth following into the mid-1970s, when publicity about the drug’s psychiatric ill effects slowed usage. Nevertheless, a revival of LSD use occurred in the United States and elsewhere in the 1990s. Explore Britannica Premium! Go beyond the basics with trusted, in-depth knowledge for professionals, students, and lifelong learners. SUBSCRIBE John Philip Jenkins