Psilocybin for depression is one of the most closely watched areas in mental health research. Over the past decade, universities and hospitals in London, Zurich, Baltimore and beyond have tested whether a few doses of psilocybin, combined with psychological support, can help people with depression, including treatment-resistant depression. This article summarizes the key clinical trials in plain language, explains what they found, and sets out what is still unknown.
This article is for general information only. It is not medical advice. If you are struggling with depression, please speak to a doctor or a mental health professional. Do not stop or change any medication without medical advice.
Why Researchers Are Studying Psilocybin for Depression
Depression affects hundreds of millions of people worldwide. Many people improve with talking therapy, antidepressants or both. However, a large group does not respond well to existing treatments. Doctors often describe this as "treatment-resistant depression."
Psilocybin works differently from common antidepressants. Instead of being taken every day, it is given once or twice in a supervised session. Researchers believe it may help by temporarily loosening rigid patterns of thought and brain activity. Our guide to psilocybin and the brain explains this idea in more detail.
Key Clinical Trials of Psilocybin for Depression
2016: The First Open-Label Study in London
At Imperial College London, researchers gave psilocybin to 12 people with treatment-resistant depression in a small feasibility study [1]. Every patient knew they were receiving psilocybin, and there was no control group. Even so, depression scores dropped markedly one week later, and many patients still showed improvement after three months. The study was too small to prove anything, but it opened the door to larger trials.
2021: Johns Hopkins Waiting-List Trial
Next, a team at Johns Hopkins University randomly assigned 24 adults with major depression to receive psilocybin therapy either immediately or after a delay [2]. Those who received psilocybin first showed much larger improvements than those still waiting. However, a waiting list is a weaker comparison than a placebo.
2021: Psilocybin Versus Escitalopram
In the same year, Imperial College compared psilocybin with escitalopram, a widely used antidepressant, in 59 patients [3]. On the main depression scale, the difference between the two treatments was not statistically significant. Several secondary measures favored psilocybin, but the authors cautioned against drawing firm conclusions from them.
2022: The Largest Trial in Treatment-Resistant Depression
A trial run by COMPASS Pathways at sites in Europe and North America tested a single dose of psilocybin in 233 people with treatment-resistant depression [4]. A 25 mg dose reduced depression scores more than a 1 mg dose after three weeks. On the other hand, the effect was not lasting for everyone, and side effects such as headache, nausea and dizziness were common. A small number of participants in all groups also reported suicidal thoughts or self-harm.
2023: Placebo-Controlled Trials in Zurich and the US
At the University of Zurich in Switzerland, researchers ran a double-blind trial comparing a single dose of psilocybin with placebo in people with major depression [5]. Psilocybin, given with psychological support, reduced depression symptoms more than placebo two weeks after treatment. Similarly, a US trial at 11 research sites compared a single 25 mg dose of psilocybin with niacin, an active placebo, in 104 adults [6]. The psilocybin group showed larger improvements that lasted throughout the six-week follow-up.
What the Evidence on Psilocybin for Depression Shows So Far
Taken together, these trials suggest that psilocybin for depression can produce rapid improvements, sometimes within a day or a week, after only one or two doses. In addition, some patients benefit for months. That is very different from standard antidepressants, which usually take several weeks to work and must be taken daily.
Nevertheless, the results are mixed. Some people improve a lot, while others notice little change, and benefits can fade. Most trials have also been fairly small and short. Similar patterns appear in research on psilocybin for anxiety and in early work on anorexia.
Limits and Open Questions
- Blinding: psilocybin has strong effects, so most participants can guess whether they received it. This makes placebo comparisons difficult.
- Expectations: heavy media coverage may raise hopes, which can influence results.
- Selected patients: trials exclude people with psychosis, bipolar disorder, serious heart problems and active suicidal intent, so results may not apply to everyone.
- Long-term safety: researchers still need more data on repeated treatment and long-term outcomes.
- The role of therapy: it is still unclear how much of the benefit comes from the drug and how much from the psychological support around it.
Can You Get Psilocybin for Depression Today?
In most countries, psilocybin for depression is still only available through clinical trials. No psilocybin medicine has EU-wide approval. However, Australia has allowed specially authorized psychiatrists to prescribe it for treatment-resistant depression since July 2023, and some other countries have limited access programs. Our guide to psilocybin therapy explains how supervised treatment works, and our overview of psilocybin legality in Europe and around the world covers the law.
Importantly, self-treating depression with magic mushrooms is not the same as a clinical trial. Trials use a precise dose, careful screening, trained therapists and medical monitoring. Some antidepressants also interact with psilocybin, and combining it with lithium has been linked to seizures. Read our guide to psilocybin and antidepressants for details.
Frequently Asked Questions
How quickly does psilocybin work for depression?
In several trials, depression scores fell within days of a single dose. However, the size and length of the effect varied a lot between people.
Is microdosing the same as psilocybin therapy for depression?
No. The trials above used full, supervised doses. Microdosing uses much smaller amounts, and so far the evidence for it is much weaker. Read our guide to microdosing magic mushrooms to learn more.
Is psilocybin approved as a depression treatment in Europe?
Not at EU level. Access in Europe is mainly through approved clinical trials and limited national programs.
Conclusion: A Promising but Unfinished Story
Research on psilocybin for depression has moved from small pilot studies to large international trials in just a few years. The results are promising, especially for people who have not been helped by other treatments. Still, the evidence has real limits, and psilocybin is not a proven cure. If you live with depression, talk to a qualified professional, and follow the research as larger trials report their results.
Sources
- Carhart-Harris RL, et al. Psilocybin with psychological support for treatment-resistant depression: an open-label feasibility study. The Lancet Psychiatry. 2016. doi:10.1016/S2215-0366(16)30065-7
- Davis AK, et al. Effects of psilocybin-assisted therapy on major depressive disorder. JAMA Psychiatry. 2021. doi:10.1001/jamapsychiatry.2020.3285
- Carhart-Harris R, et al. Trial of psilocybin versus escitalopram for depression. New England Journal of Medicine. 2021. doi:10.1056/NEJMoa2032994
- Goodwin GM, et al. Single-dose psilocybin for a treatment-resistant episode of major depression. New England Journal of Medicine. 2022. doi:10.1056/NEJMoa2206443
- von Rotz R, et al. Single-dose psilocybin-assisted therapy in major depressive disorder: a placebo-controlled, double-blind, randomised clinical trial. eClinicalMedicine. 2023. doi:10.1016/j.eclinm.2022.101809
- Raison CL, et al. Single-dose psilocybin treatment for major depressive disorder: a randomized clinical trial. JAMA. 2023. doi:10.1001/jama.2023.14530
