Psychedelic therapy
Psychedelic therapy refers to the proposed use of psychedelic drugs in mental health treatment practices. The drugs proposed to treat mental disorders and improve well-being include mescaline, LSD, psilocybin and psilocin, ayahuasca, DMT, 5-MeO-DMT, ibogaine and MDMA. As of 2021, psychedelic drugs are controlled substances in most countries and psychedelic therapy is not legally available outside clinical trials, with some exceptions.
The procedure for psychedelic therapy differs from that of therapies using conventional psychiatric medications. While conventional medications are usually taken without supervision at least once daily, in contemporary psychedelic therapy the drug is administered in a single session in a therapeutic context. The therapeutic team prepares the patient for the experience beforehand and helps them integrate insights from the drug experience afterwards. After ingesting the drug, the patient normally wears eyeshades and listens to music to facilitate focus on the psychedelic experience, with the therapeutic team interrupting only to provide reassurance if adverse effects such as anxiety or disorientation arise.
As of 2022, the body of high-quality evidence on psychedelic therapy remains relatively small and more, larger studies are needed to reliably show the effectiveness and safety of psychedelic therapy's various forms and applications. On the basis of favorable early results, ongoing research is examining proposed psychedelic therapies for conditions including major depressive disorder, anxiety and depression linked to terminal illness, and post-traumatic stress disorder. The United States Food and Drug Administration has granted "breakthrough therapy" status, which expedites the potential approval of promising drug therapies, to psychedelic therapies using psilocybin and MDMA.
Psychedelic substances have a long history of use in spiritual and therapeutic contexts, from ancient shamanic practices to mid-20th-century clinical research. After widespread experimentation with LSD, psilocybin, and other psychedelics in the 1950s and 1960s, regulatory crackdowns—including the U.S. Controlled Substances Act of 1970—largely halted scientific study, though underground therapy continued. Interest resurged in the early 2000s with advances in neuroscience and imaging, leading to renewed clinical trials. Research faces methodological limitations, ethical concerns, and issues of equitable access. Additionally, commercialization, patenting, and venture capital investment have raised debates over ethics, cultural appropriation, and potential conflicts of interest. Despite these challenges, public interest and regulated therapeutic programs—including psilocybin facilitator training in Oregon—signal a growing integration of psychedelics into mental health treatment and wellness practices.
History
Prehistoric use of psychedelic substances
Humans have long consumed psychedelic substances derived from cacti, seeds, bark, and roots of various plants and fungi. Since ancient times, shamans and medicine men have used psychedelics as a way to gain access to the spirit world. Though western culture usually views the practice of shamans and medicine men as predominantly spiritual in nature, elements of psychotherapeutic practice can be read into the entheogenic or shamanic rituals of many cultures.Research in the mid-20th century
Shortly after Albert Hofmann discovered the psychoactive properties of LSD in 1943, Sandoz Laboratories began widespread distribution of LSD to researchers in 1949. Throughout the 1950s and 1960s, scientists in several countries conducted extensive research into experimental chemotherapeutic and psychotherapeutic uses of psychedelic drugs. In addition to spawning six international conferences and the release of dozens of books, over 1,000 peer-reviewed clinical papers detailing the use of psychedelic compounds were published by the mid-1960s. Proponents believed that psychedelic drugs facilitated psychoanalytic processes, making them particularly useful for patients with conditions such as alcoholism that are otherwise difficult to treat. However, many of these trials did not meet the methodological standards that are required today.Researchers like Timothy Leary felt psychedelics could alter the fundamental personality structure or subjective value-system of an individual to great potential benefit. Beginning in 1961, he conducted experiments with prison inmates in an attempt to reduce recidivism with short, intense psychotherapy sessions. Participants were administered psilocybin during these sessions weeks apart with regular group therapy sessions in between. Psychedelic therapy was also applied in a number of other specific patient populations including individuals with alcoholism, children with autism, and persons with terminal illness.
Regulation and prohibition in the late 20th century
Throughout the 1960s, concerns raised about the proliferation of unauthorized use of psychedelic drugs by the general public resulted in the imposition of increasingly severe restrictions on medical and psychiatric research conducted with psychedelic substances. Many countries either banned LSD outright or made it extremely scarce, and, bowing to governmental concerns, Sandoz halted production of LSD in 1965. During a congressional hearing in 1966, Senator Robert F. Kennedy questioned the shift of opinion, stating, "Perhaps to some extent we have lost sight of the fact that can be very, very helpful in our society if used properly." In 1968, Dahlberg and colleagues published an article in the American Journal of Psychiatry detailing various forces that had successfully discredited legitimate LSD research. The essay argues that individuals in government and the pharmaceutical industry sabotaged the psychedelic research community by canceling ongoing studies and analysis while labeling genuine scientists as charlatans.Studies on medicinal applications of psychedelics ceased entirely in the United States when the Controlled Substances Act was passed in 1970. LSD and many other psychedelics were placed into the most restrictive "Schedule I" category by the United States Drug Enforcement Administration. Schedule I compounds are claimed to possess "a high potential for abuse and the potential to create severe psychological and/or physical dependence" and have "no currently accepted medical use", effectively rendering them illegal to use in the United States for all purposes. Despite objections from the scientific community, authorized research into therapeutic applications of psychedelic drugs had been discontinued worldwide by the 1980s.
Despite broad prohibition, unofficial psychedelic research and therapeutic sessions continued nevertheless in the following decades. Some therapists exploited windows of opportunity preceding scheduling of particular psychedelic drugs. Informal psychedelic therapy was conducted clandestinely in underground networks consisting of sessions carried out both by licensed therapists and autodidacts within the community. Due to the largely illegal nature of psychedelic therapy in this period, little information is available concerning the methods that were used. Individuals having published information between 1980 and 2000 regarding psychedelic psychotherapy include George Greer, Ann and Alexander Shulgin, Myron Stolaroff, and Athanasios Kafkalides.
Resurgence in the early 21st century
In the early 2000s, a renewal of interest in the psychiatric use of psychedelics contributed to an increase in clinical research centering on the psychopharmacological effects of these drugs and their subsequent applications. Advances in science and technology allowed researchers to collect and interpret extensive data from animal studies, and the advent of new technologies such as PET and MRI scanning made it possible to examine the sites of action of hallucinogens in the brain. Furthermore, retrospective studies involving users of illicit drugs as voluntary subjects were conducted, allowing data to be collected on how psychedelics affect the human brain while simultaneously sidestepping bureaucratic difficulties associated with providing illegal substances to subjects. The new century also ushered in a broader change in political attitude towards psychedelic medicine—specifically within the Food and Drug Administration. Curtis Wright, then deputy director of the FDA Division of Anesthetic, Critical Care and Addiction Drugs explained a motivation for this change: "the agency was challenged legally in a number of cases and also underwent a process of introspection, asking 'Is it proper to treat this class of drugs differently?'"As of 2014, global treaties listing LSD and psilocybin as "Schedule I" controlled substances continues to inhibit a better understanding of these drugs. Much of the renewed clinical research has been conducted with psilocybin and MDMA in the United States with special permission and breakthrough therapy designations by the FDA, while other studies have investigated the mechanisms and effects of ayahuasca and LSD. MDMA-assisted psychotherapy is being actively researched by Resilience Therapeutics, formerly known as Lykos Therapeutics and MAPS.
As of 2023, many new centers for psychedelics research have been launched, including the Centre for Psychedelic Research at Imperial College London, the UC Berkeley Center for the Science of Psychedelics, the Center for Psychedelic and Consciousness Research at Johns Hopkins University, the Transdisclipinary Center for Research in Psychoactive Substances at the University of Wisconsin–Madison, the Center for Psychedelic Research and Therapy at Dell Medical School at the University of Texas at Austin, the Center for Psychedelic Psychotherapy and Trauma Research at the Icahn School of Medicine at Mount Sinai, the Psychae Institute in Melbourne, and the Naut sa mawt Center for Psychedelic Research at Vancouver Island University. Harvard will create a Study of Psychedelics in Society and Culture.
A survey published in 2023 found strong support for psychedelic therapy among psychiatrists in the United States, revealing a significant positive shift in attitudes toward this treatment modality in comparison to a previous survey published in 2018. More than half of psychiatrists in the 2023 study expressed intentions to incorporate psychedelic therapy into their practice if regulatory approval is granted. In Australia, authorised psychiatrists can prescribe psilocybin for treatment-resistant depression, and MDMA for post-traumatic stress disorder.
In 2024, an FDA advisory panel voted against approving MDMA-assisted therapy for PTSD, "raising questions about the credibility of the research being conducted and the safety of those involved in the trials". The FDA advisors voted 9-2 that the available data didn't show MDMA was effective in treating PTSD, and 10-1 that the benefits of MDMA-assisted therapy did not outweigh the risks. However, the U.S. Department of Veterans Affairs has since committed $1.5 million to its first study on psychedelic-assisted therapy for PTSD and alcohol use disorder in veterans, signaling growing institutional interest despite FDA skepticism.
In addition, veteran-led nonprofits like the Heroic Hearts Project are working with researchers to expand access to psychedelic therapies for military personnel and veterans.
In 2025, PsychedeliCare launched a European Citizens' Initiative aiming to enable the implementation of psychedelic-assisted therapies in the EU to ensure safe and affordable psychedelic-assisted therapies.