top of page


Despite rapid progress in all areas of conventional medicine, the treatments available remain limited. This most certainly includes psychiatry. Therefore, in certain circumstances, doctors must recognize that patients may benefit from alternative treatments. These alternatives include drugs and herbs which may be currently illegal depending on the country, but have been part of non-Western pharmacopoeias for centuries, if not more. One such drug is psilocybin, a potent hallucinogen found in fungi of the genus Psilocybe.

Psilocybin has received a lot of attention recently. This follows numerous high-profile press articles on the subject, as well as the decision to decriminalize « magic mushrooms » (as they are frequently called) in the cities of Denver and Oakland. Several studies have also focused on the medicinal applications of this drug in a controlled environment. Although his research is still in its infancy, researchers have found that psilocybin and other psychedelic drugs have potential medicinal benefits, which will be discussed below. Despite its potential benefits, psilocybin currently remains a Category I drug under the Controlled Substances Act, 1970.

The purpose of this article is not to endorse self-medication. It is for educational purposes only. If a person decides to experiment with psilocybin or any other psychedelic drug, they should do so in a clinical setting or with a guide experienced in monitoring and caring for people under the influence of such drugs. Psilocybin is a particularly powerful psychedelic. This can produce unpredictable results. people who use psilocybin may have impaired judgment and / or act recklessly.

Why they are called « magic mushrooms »

Psychedelic drugs have been used by many shamanic cultures dating back to prehistoric times. For these cultures, psychedelics are not taken for recreational purposes; they provide a way to communicate with ancestors and spirits that are supposed to transcend the bodily world with which we interact on a daily basis. This is true worldwide. It is also true that various types of mushrooms, mainly those of the genera Psilocybe or Amanita, were often at the origin of these psychedelic experiences.

Although the genus Psilocybe can be found around the world, it appears to have been more widely used among Native American tribes in Central America and Mexico. The use has become more common in traditional Western culture, largely thanks to R. Gordon Wasson, a mushroom lover and New York banker. Wasson went to Oaxaca in 1955 and met a shaman who introduced him to mysticism and to mushrooms containing psilocybin. Wasson then published an article on his experience in a 1957 issue of Life magazine. The title of the article was « In Search of the Magic Mushroom ».

Wasson also sent samples to Albert Hofman, a chemist who had synthesized lysergic acid diethylamide (more commonly known as LSD or acid) in 1938 by isolating compounds found in ergot, a fungus affecting rye seeds. Hofman isolated and synthesized psilocybin from mushroom samples in 1958.

What are the effects of psilocybin?

Mushrooms containing psilocybin tend to induce profound changes in mood, thinking and perception by binding to serotonin receptors in the brain (especially 5-hydroxytryptamine (HT) 2A receptors). The experience (often called « travel ») is very variable and can be influenced by an individual’s mood and environment (often called « together »). You usually start to feel the effects of psilocybin about 30 to 45 minutes after ingesting it, and the effects tend to last for about four to six hours, depending on the dosage. The « peak » of the effects, when they are at their maximum, generally occurs between two and three hours after consumption.

Although auditory and visual hallucinations are common, people taking psilocybin can also experience deeply spiritual epiphanies that are difficult to remember completely once the effects are gone. People who have participated in psilocybin studies have said that the experience can be life-changing and that it has allowed them to become more insightful and thoughtful. The drug can also produce euphoria and a feeling of connectedness with others or with the world in general.

The data suggest that psilocybin is much less potent than a drug like LSD and that it poses a very low risk of overdose toxicity (estimated at 1,000 times an effective dose), but it can sometimes have unpleasant effects. Psilocybin is known to occasionally but rarely have side effects such as hypertension, tachycardia, nausea, vomiting, anxiety, dizziness, confusion and increased sensitivity to light due to dilation pupils. Hallucinations may become very intense depending on the doses taken, and some people can sometimes suffer from what is called a « bad trip ». This involves unpleasant, even disturbing thoughts, hallucinations which can lead to anxiety, confusion. In a therapeutic setting, it is simply a work of confrontation with its dark side in order to get rid of it once and for all.

Psilocybin clinical studies

Although clinical studies on psilocybin have been difficult to conduct in the United States since the enactment of the Controlled Substances Act, which severely restricted scientific research on all Schedule I drugs, limited research has been performed in the United States and abroad. These studies indicate that psilocybin may be effective in combating anxiety and depression, especially in people at the end of their lives with terminal illnesses, such as cancer. Mitchell et al. Noted that symptoms of this form of anxiety and / or depression occur in 30% to 40% of cancer patients in the hospital setting. However, therapies to resolve this problem are lacking. In their 2016 article, Ross et Al pointed out that « there is currently no effective pharmacotherapy or pharmacological and psychosocial intervention combined to treat this type of distress and clinical needs in cancer patients. »

A study by Griffiths et al. Published in 2016 showed that a group of people with clinical anxiety and depression caused by a life-threatening cancer diagnosis demonstrated improved mood and attitude immediately after consuming psilocybin. Six months later, during follow-up, these results were largely unchanged. A study by Grob et al. Gave similar results.

For their part, Ross and his collaborators found that a single dose of psilocybin, combined with psychotherapy, effectively treated the existential discomfort caused by awareness of imminent death due to the disease. The effects were sustained for as long as 26 weeks; the majority of patients with anxiety and depressive states were able to develop better behavior in the face of death, reduced existential distress, and improved quality of life in general. The study authors did not report any adverse medical or psychiatric

Limited research has also indicated that psilocybin can also reduce symptoms associated with obsessive-compulsive disorder (OCD). After hearing anecdotally about the correlation between symptom alleviation and psilocybin, Moreno and his colleagues performed a double-blind random test on nine patients with OCD between 2001 and 2004. They tested four dosage levels (sub-hallucinogenic, low, medium and high) with at least one week apart. Eight of the nine patients had a 25% or more symptom reduction on the Yale-Brown obsessive-compulsive scale 24 hours after ingesting psilocybin. Six of the nine saw a 50% decrease 24 hours after the session. These effects do not seem to correlate with the dosage.

Could people who find it hard to get rid of their addiction to alcohol or nicotine benefit from it? In a validation of concept study published in 2015, Bogenschutz et Al. Administered psilocybin to 10 alcoholic volunteers. Although psilocybin did not cause abstinence, all of the patients involved reduced their alcohol consumption. A similar study currently being conducted by Kelley O’Donnell of New York University also found that psilocybin could potentially help patients with alcohol use disorders. « Some people have very deep psychological experiences that change the way they see themselves and how alcohol affects their social relationships, » O’Donnell told an audience during a presentation at the annual meeting of the American Psychiatric Association. in 2019 in San Francisco last month. . « Therapy can work with this change in perception to generate lasting transformation. »

Meanwhile, 15 cigarette smokers were enrolled in a 15-week open pilot study including cognitive behavioral therapy (CBT), as well as psilocybin administration at weeks 5, 7 and 13. During the first four weeks, patients were allowed to smoke, although they were forced to participate in CBT. They then had to quit smoking during the fifth week, which coincided with their first dose of psilocybin. Johnson et al., Who published the study in 2017, reported that 80% of participants were still non-smokers at the following six-month follow-up; 67% remained smoke-free a year later; and 60% still did not smoke during their long-term follow-up (extremes = 16-57 months).

People who were not affected by the existential severity of death, OCD or drug addiction would also have benefited from the use of psilocybin. In articles published in 2006 and 2008, Griffiths et Al found that patients’ mood and attitudes improved after the use of psilocybin and that these effects were still noticeable for the 36 patients involved in the study well after ‘initial experience. In addition, 67% of the 36 patients in the 2006 study said it was one of the five most important experiences of their lives two months after the session. 14 months later (16 months after ingestion of psilocybin), these results were largely unchanged.

It is difficult to understand how psilocybin can produce therapeutic improvements over several months or even more, even if the effects of the drug last only a few hours. It is possible that this may disrupt the synaptic networks in the brain, causing their disorder and recovery. It has also been proposed that psilocybin may have anti-inflammatory effects on the brain that specifically target serotonergic systems. If this is the mechanism of action, psilocybin could potentially be a useful tool in the fight against mental illnesses such as depression, anxiety and even post-traumatic stress disorder. But we have only seen that the tip of the iceberg and further research will be needed to establish the validity of these claims.

It is important that clinicians and mental health professionals keep in mind the alternatives that may exist that go beyond conventional treatments – psilocybin is just one example. There are good reasons to be optimistic about the therapeutic usefulness of psilocybin, provided that it is administered in an appropriate environment and in the presence of competent people who can provide accompaniment and support. However, we must proceed with caution, as the data are still quite limited. As beneficial as psilocybin can be, it remains a very potent and currently illegal drug.

Samoon Ahmad, M.D. is a Professor of Psychiatry, NYU School of Medicine; Unit Chief, Inpatient Psychiatry, Bellevue Hospital Center; and Founder of Integrative Center for Wellness in New York City.

bottom of page