What is the clinical evidence on psilocybin for the treatment of psychiatric disorders? A systematic review
Henrique Castro Santos, João Gama Marques
Porto Biomedical Journal 2021 DOI: 10.1097/j.pbj.0000000000000128 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Systematic review Randomized Open-label Peer reviewed |
|---|---|
| Topics | Depression Psilocybin |
| Keywords | Hallucinogen Clinical trial Depression economics Obsessive compulsive Clinical psychology Psychotherapist Cognition |
| Citations | 37 |
| Key findings | Psilocybin shows promising therapeutic effects for depression, OCD, and substance use disorder, with the strongest evidence for depression from three randomized controlled trials. |
Abstract
Abstract
Background: Psilocybin is a predominant agonist of 5HT 1A and 5HT 2A/C receptors and was first isolated in 1958, shortly before it became a controlled substance. Research on the potential therapeutic effects of this compound has recently re-emerged alongside what is being addressed as a psychedelic renaissance.
Methods: In this paper we performed a systematic review of the clinical trials conducted so far regarding the therapeutic effects of psilocybin on psychiatric disorders. The eligibility criteria included clinical trials that assessed psilocybin's potential therapeutic effects on patients with psychiatric disorders. Nine hundred seven articles were found and screened in regard to the title, from which 94 were screened through abstract and 9 met the eligibility criteria and were included.
Results: The papers published focused on 3 disorders: depression, obsessive-compulsive disorder (OCD) and substance use disorder (namely tobacco and alcohol). Psilocybin has shown a relatively safe profile and very promising results, with reductions found on most of the psychiatric rating scales’ scores. Research on depression showed the most solid evidence, supported by 3 randomized controlled trials. Studies on OCD and substance use disorder showed more limitations due to their open-label design.
Conclusions: Altogether, the results from the studies reviewed in this paper suggest a substantial therapeutic potential. This calls for further research to confirm the results observed so far and further explain the underlying mechanisms.
Comparable studies
Other systematic reviews and meta-analyses on psilocybin for depression, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Therapeutic effects of classic serotonergic psychedelics: A systematic review of modern‐era clinical studies Patients with cancer- or illness-related anxiety and depression, major depressive... | 2020 | Systematic review | n = 188 |
| The experimental effects of psilocybin on symptoms of anxiety and depression: A meta-analysis People with elevated symptoms of anxiety and depression | 2020 | Meta-analysis | n = 117 |
| Psychedelics in the treatment of unipolar mood disorders: a systematic review Patients with broadly defined unipolar mood disorders | 2016 | Systematic review | n = 423 |
| Psychedelic therapy for depressive symptoms: A systematic review and meta-analysis. Participants in studies of psychedelic therapy for depressive symptoms (Major... | 2023 | Systematic review with meta-analysis | n = 14 |
| Serotonergic hallucinogens in the treatment of anxiety and depression in patients suffering from a life-threatening disease: A systematic review. Patients with life-threatening diseases and symptoms of anxiety or depression | 2018 | Systematic review | n = 445 |