Psilocybin therapy

Several rigorous studies have been conducted on psilocybin therapy.[1] These have studied its effectiveness for treatment of obsessive compulsive disorder (OCD),[2] anxiety and depression in patients with cancer diagnoses,[3][4][5] tobacco addiction,[6] and alcohol use disorder.[7] All of the studies showed clinical efficacy and none reported clinically significant adverse effects.[1] Further studies are underway as of 2020 with improved study designs and larger sample sizes.[1]

Therapeutic effects of psychedelics such as psilocybin on a range of mental pathologies appear to be explained by changes at the level of molecular genetics, in turn triggering neuronal activity, causing entropic brain activity and thereby mystical experiences.[8] Psilocybin may be glutamatergic and influence neurotransmission in prefrontal-limbic circuits of the brain, causing neuroplastic changes that bring long-lasting antidepressant effects.[9] Many aspects of the biological mechanisms of therapeutic effects caused by psilocybin remain uncertain.[8]

During the 1950s and 1960s, research with psychedelics was conducted in the absence of rigorous guidelines. Lack of informed consent led to substantial and long-lasting harm to some subjects, averting the public away from use of psychedelics in medical practice. Further, unsupported claims led to drug abuse in the absence of a formal and supervised setting.

More recently, research on the effectiveness of psilocybin therapy has been conducted under strict ethical guidelines, with fully informed consent and a prescreening to avoid people with psychosis taking part.[10] Additionally, the experimenters conducting it are trained to properly administer the drug, and suggestions for experiments have to comply with the APA's ethical guidelines as well as pass expert reviews before they can be carried out.[11] Furthermore, potential harms of psilocybin, such as psychosis and hallucinations, have only been linked to recreational and unsupervised nonmedical use of the drug.[12] Experts agree that the drug treatment is still under development and they do not recommend to the public to try and self-medicate their mental states. Acute effects, such as anxiety, fear states, and increases in heart rate and blood pressure, can occur during the time of drug action, and without supervision dangerous behaviors can emerge. However, trained specialists can readily manage this and usually no negative long-term effects are reported.[10] In comparison to many other drugs, psilocybin is relatively harmless physiologically.

In 1959, Albert Hofmann, as Swiss chemist, was the first person to ever extract pure psilocybin from the mushrooms that commonly contain it (Psilocybe mexicana). Sandoz, the company that Hofmann worked for at that time, then began to sell the active compound to clinicians and physicians all across the world, which then used the drug as an aiding substance in psychedelic psychotherapy.

In August 1960, Timothy Leary, a psychology professor from Harvard University, traveled to Mexico to conduct a self-experiment using psilocybin mushrooms. After trying pure, extracted psilocybin he decided to experiment even more with the substance, even administering it to his students. In conducting his experiment, he was assisted by his colleague, prof. Dr. Richard Alpert. One of their experiments consisted of administering psilocybin to prisoners, attempting to find out whether it could help reduce recidivism rate and constitute an effective psychotherapy aid. In fact, the results showed a recidivism rate that was 40% lower than expected. In another experiment, Leary and Alpert gave psilocybin to divinity graduate students with the aims of observing the effects of the drug on spiritually predisposed subjects. Students confirmed afterwards that their experience had made positive, lasting changes in their lives.

In 1963, however Dr. Leary and Dr. Alpert were faced with disapproval from other colleagues at Harvard University, eventually leading to their suspension from their jobs at the University. Academics criticized their experiments and their project, describing it as irresponsible and dangerous.[13]

Around the years 1960-1977, psilocybin was first studied as a psychotherapeutic drug. Research on humans in this field was approved by the United States Food and Drug Administration (FDA), but after a while it was ended and did not continue until the late 1990s, when research on the medical use of psilocybin began again.

In 2018 the United States Food and Drug Administration (FDA) granted breakthrough therapy designation for psilocybin-assisted therapy for treatment-resistant major depressive disorder.[14] In 2019, the FDA also granted breakthrough therapy designation for psilocybin therapy treating major depressive disorder more generally.[15]