Psychedelics for Major Depressive Disorder: Evidence Review
What randomized trials of psilocybin with psychological support have found for major depressive disorder, including sample sizes, comparators, side effects, limits and regulatory status.
Content last updated . This page has not been medically reviewed.
Quick answer
Several randomized trials suggest that psilocybin given with psychological support reduced depression scores in adults with major depressive disorder (MDD), but the trials are small, short, and hard to blind. No psilocybin product was found approved for depression in the sources read. This page describes research, not treatment advice. If you are thinking about harming yourself, call or text 988 (US Suicide & Crisis Lifeline) or call 911.Evidence labels used here: promising but limited means positive results from small or short trials; mixed means results disagree; approved medicine means a regulator has approved it for that use. Psilocybin for MDD currently fits promising but limited. For the compound itself see the psilocybin guide.
What was tested
All trials below used synthetic or capsule psilocybin in a clinic or research setting, with trained staff and psychological support before, during and after the session. That is a study treatment, not the same thing as eating mushrooms. Amounts are not listed here because they are study protocols, not guidance. See clinical formulations vs nonmedical products.Main trials in major depressive disorder
| Trial | Design and size | Comparator | Result |
|---|---|---|---|
| Raison 2023 [1] | Phase 2, 104 adults, 11 US sites, single session, central raters, participants and staff blinded | Niacin placebo, with psychological support | Depression scores fell more with psilocybin than niacin at day 43. Adverse events and severe adverse events were more common with psilocybin; none were serious. |
| Carhart-Harris 2021 [2] | Phase 2, 59 adults with long-standing MDD, 6 weeks, double-blind | The antidepressant escitalopram (plus a very low psilocybin amount) | No significant difference on the main measure. Many secondary results favored psilocybin but were not corrected for multiple comparisons. |
| Davis 2022 [3] | 27 adults at one center, not on antidepressants, two sessions plus about 11 hours of supportive therapy | Waiting list (delayed treatment) | Large drops in depression scores at weeks 1 and 4 after treatment. People knew whether they had been treated. |
Raison 2023 excluded people with a history of psychosis or mania, active substance use disorder, or active suicidal ideation with intent, and people on psychiatric medicines were included only after a medication taper arranged by the study. [1] Funding was not stated in the abstract we read.
What combining the trials shows
A 2026 meta-analysis of six randomized trials found that standard-dose psilocybin reduced depression scores more than controls (standardized mean difference -1.05), but the result varied a lot between trials. When trials with waiting-list controls were removed, the effect was smaller (-0.70). [4] The same review found more headache and nausea with psilocybin in the days after treatment, and no benefit for the low-dose groups. [4] The authors called for work on the methodological differences between trials. [4]Why caution is needed
- Blinding. Participants often know whether they received a strong-acting drug. The FDA calls this functional unblinding and says it can cause expectation bias. [5]
- Therapy vs drug. The FDA states that the contribution of psychotherapy to the treatment effect is not established. [5]
- Selected participants. Trials screen people, so results may not apply to everyone with depression.
- Short follow-up. Most trials above lasted weeks, not years.
- Safety. Side effects such as headache and nausea were more common, and a trial in treatment-resistant depression recorded suicidal thoughts or self-injury in all dose groups. [6] See treatment-resistant depression and adverse effects and contraindications.
Regulatory status
NIDA reports that the FDA has granted Breakthrough Therapy designation to two psilocybin formulations being studied for depression; that designation speeds review and is not approval. [7] The FDA published final guidance on designing psychedelic drug trials in July 2026. [5] We did not verify other countries' regulators. Laws and approvals change; this is not legal advice.What this does not tell us
Proper evidence not found for head-to-head comparisons of psilocybin with several standard treatments, or for long-term outcomes in MDD beyond a few months in the randomized trials read. Do not stop or change a prescribed medicine because of this page; talk with your prescriber.Frequently asked questions
Is psilocybin approved to treat depression?
In the sources read, no psilocybin product is approved for depression. The FDA has granted Breakthrough Therapy designation to two formulations under study, which is not approval. [7]
Did psilocybin work better than an antidepressant?
In one 59-person trial, psilocybin and escitalopram did not differ significantly on the main 6-week measure. [2]
Are the results reliable?
They are promising but limited. Trials are small, many participants can tell they got the drug, and the contribution of therapy is not established. [5][4]
What side effects were reported?
A 2026 meta-analysis found more headache and nausea after psilocybin than after control treatment. [4] A US trial found more adverse events overall and more severe ones, but no serious treatment-related events. [1]
References
- Raison CL et al. Single-dose psilocybin treatment for major depressive disorder: a randomized clinical trial. JAMA 2023. Read 2026-10-22.
- Carhart-Harris R et al. Trial of psilocybin versus escitalopram for depression. N Engl J Med 2021. Read 2026-10-22.
- Davis AK et al. Effects of psilocybin-assisted therapy on major depressive disorder: a randomized clinical trial. JAMA Psychiatry 2022. Read 2026-10-22.
- Psilocybin-assisted therapy for major depressive disorder: perspective from meta-analysis. J Affect Disord 2026. Read 2026-10-22.
- U.S. Food and Drug Administration. Psychedelic Drugs: Considerations for Clinical Investigations, guidance for industry. Page content current as of 07/13/2026 (guidance PDF: https://www.fda.gov/media/169694/download). Read 2026-10-22.
- Goodwin GM et al. Single-dose psilocybin for a treatment-resistant episode of major depression. N Engl J Med 2022. Read 2026-10-22.
- National Institute on Drug Abuse. Psychedelic and Dissociative Drugs. Read 2026-10-22.