Psilocybin Research Library
What current clinical research actually shows
Clinical research into psilocybin is developing rapidly.
The evidence is stronger for some conditions than others.
Satya provides legal Oregon psilocybin services.
The studies below describe clinical research and should
not be interpreted as guarantees of individual outcomes.
Six Areas of Psilocybin Research
Explore the current state of clinical evidence for each condition.
1. Depression
Multiple controlled trials have examined major depression, including treatment-resistant depression.
Explore Research →2. PTSD & Trauma
Human clinical trials are underway, but efficacy evidence is not yet established.
Explore Research →3. Anxiety
Strongest evidence is in anxiety and depression associated with serious illness and cancer.
Explore Research →4. Alcohol Use Disorder
Randomized research has found fewer heavy-drinking days when psilocybin was combined with psychotherapy.
Explore Research →5. OCD
Small human studies show promising early signals.
Explore Research →6. End-of-Life Distress
Several controlled studies in people with life-threatening cancer report reductions in existential distress and anxiety.
Explore Research →Clinical-trial results are evidence about study populations and protocols.
They do not establish that Oregon psilocybin services at Satya will reproduce the same outcomes.
Trial of Psilocybin versus Escitalopram for Depression
Carhart‑Harris et al.
2021
59 adults with long-standing moderate-to-severe major depressive disorder.
Phase 2 double-blind randomized comparison of psilocybin vs escitalopram over six weeks, with psychological support in both groups.
What They Found
• The prespecified primary depression outcome did not show a statistically significant difference between psilocybin and escitalopram at week 6. • Several secondary outcomes favored psilocybin, but those analyses were not corrected for multiple comparisons.
Why It Matters
A useful comparator trial because it tested psilocybin against an established SSRI rather than only against placebo.
Important Limitation
• Small selected sample, six-week duration, and functional-unblinding concerns. • The negative primary endpoint is critical and should not be obscured by favorable secondary outcomes.
Effects of Psilocybin-Assisted Therapy on Major Depressive Disorder: A Randomized Clinical Trial
Davis et al.
2021
27 adults with major depressive disorder were randomized; 24 completed the intervention and follow-up.
Randomized waiting-list controlled clinical trial with two psilocybin sessions plus supportive psychotherapy.
What They Found
• Depression severity fell substantially after psilocybin-assisted therapy compared with the delayed-treatment period. • The published trial reported high response and remission rates during the four-week follow-up. • The article is one of the clearer early controlled demonstrations of clinically measured improvement in major depressive disorder.
Why It Matters
A foundational modern controlled trial supporting the depression SEO page, while still representing a small, highly selected research sample.
Important Limitation
• Small sample and waiting-list design; participants could not be meaningfully blinded to an intense psychedelic intervention. • The intervention included structured psychological support and two psilocybin sessions, so results cannot be attributed to a typical Oregon service-center session alone. • Short controlled follow-up compared with the chronic course of depression.
Single-Dose Psilocybin for a Treatment-Resistant Episode of Major Depression
Goodwin et al.
2022
233 adults with treatment-resistant depression: 79 in 25 mg, 75 in 10 mg, and 79 in 1 mg groups.
Phase 2 double-blind dose-ranging randomized trial of 25 mg, 10 mg, or 1 mg psilocybin with psychological support.
What They Found
• At week 3, the 25 mg group had a significantly greater reduction in MADRS depression score than the 1 mg control group. • The 10 mg group did not differ significantly from the 1 mg group on the primary comparison. • Adverse events were common; suicidal ideation/behavior or self-injury occurred across dose groups. • Sustained response through 12 weeks was not as clearly supportive as the short-term primary result.
Why It Matters
One of the largest phase 2 psilocybin depression trials and particularly relevant to treatment-resistant depression.
Important Limitation
• Treatment-resistant population and proprietary clinical protocol limit generalization to all people with depression. • Short primary endpoint and important safety findings require balanced presentation. • The trial does not establish what outcomes to expect in Oregon psilocybin services.
Single-Dose Psilocybin Treatment for Major Depressive Disorder: A Randomized Clinical Trial
Raison et al.
2023
104 adults with major depressive disorder at 11 U.S. research sites.
Phase 2 randomized, placebo-controlled, six-week trial of a single 25 mg psilocybin dose vs niacin with psychological support.
What They Found
• Psilocybin was associated with significantly greater reductions in MADRS depression scores than niacin through day 43. • Disability scores also improved more in the psilocybin group. • No serious treatment-emergent adverse events were reported in the trial.
Why It Matters
A larger multicenter MDD trial than many earlier studies and therefore important to the overall depression evidence base.
Important Limitation
• Phase 2 trial; replication and longer-term evidence remain important. • Psychedelic effects can compromise blinding even with an active placebo. • The research protocol included psychological support and strict screening.
Single-Dose Psilocybin-Assisted Therapy in Major Depressive Disorder: A Placebo-Controlled, Double-Blind, Randomised Clinical Trial
von Rotz et al.
2023
52 adults with major depressive disorder, 26 per group.
Double-blind randomized trial of a single moderate psilocybin dose (0.215 mg/kg) vs placebo with equal psychological support.
What They Found
• At 14 days, depressive symptom reductions were significantly greater with psilocybin than placebo on clinician- and self-rated measures. • MADRS remission criteria were met by 14 of 26 participants (54%) in the psilocybin group. • No serious adverse events were recorded in the trial.
Why It Matters
A placebo-controlled MDD trial supporting short-term symptom improvement after one moderate dose.
Important Limitation
• Small single-center sample and only two weeks for the primary endpoint. • Participants were carefully selected and received psychological support. • Longer and larger multicenter studies were explicitly recommended by the authors.
Efficacy and Safety of Psilocybin in Treatment-Resistant Major Depression: The EPISODE Randomized Clinical Trial
Mertens et al.
2026
144 adults with treatment-resistant depression were randomized; 142 were included in the primary efficacy analysis.
Two-center, triple-blind, phase 2b active-placebo controlled randomized trial with 25 mg, 5 mg and nicotinamide comparator conditions.
What They Found
• The prespecified primary response endpoint at week 6 was not statistically significant for 25 mg vs comparators. • Secondary outcomes provided exploratory evidence of clinically meaningful symptom reductions with 25 mg. • Safety signals included higher reports of suicidal ideation on dosing days and one case of persisting perceptual disturbance. • Within the study timeframe, a second 25 mg administration did not show additional benefit.
Why It Matters
A major 2026 study that provides essential counterweight to overly confident depression claims because its primary endpoint was not significant.
Important Limitation
• The primary endpoint was negative; favorable secondary results are exploratory. • Treatment-resistant population, specialized therapy setting and withdrawn antidepressant medication limit generalizability.
Short-Term and Late-Term Effects of Psilocybin on Symptoms in Major Depression: A Randomized Clinical Trial
Yngwe et al.
2026
35 adults with moderate to severe recurrent major depressive disorder; 17 randomized to psilocybin and 18 to niacin.
Double-blind, active-placebo controlled randomized clinical trial: 25 mg psilocybin vs 100 mg niacin, with five psychotherapeutic support sessions.
What They Found
• The primary endpoint favored psilocybin on clinician-rated depression severity at day 8. • Between-group differences also favored psilocybin on days 15 and 42; the difference was no longer significant at day 365. • Secondary self-report differences emerged by day 2 and persisted for more than three months at several time points. • Most treatment-emergent adverse events were transient and mild to moderate, but two participants reported persistent severe anxiety requiring medical attention.
Why It Matters
A very recent controlled trial that strengthens the depression page while also adding important long-term and safety nuance.
Important Limitation
• Small sample size and substantial risk of functional unblinding. • Participants were carefully screened and received structured psychotherapeutic support. • Long-term between-group benefit was not demonstrated at the 365-day clinician-rated endpoint.
Safety, Feasibility, and Preliminary Clinical Outcomes of Psilocybin-Assisted Therapy for Veterans With Severe, Treatment-Resistant PTSD: An Open-Label Pilot Clinical Trial
Armstrong et al.
2026
12 U.S. military veterans with severe, treatment-resistant PTSD.
Open-label pilot: psychotherapy plus two psilocybin sessions (15 mg and 25 mg) spaced 2-3 weeks apart.
What They Found
• The authors reported no serious adverse events and described the protocol as feasible in this small veteran sample. • Large clinician-rated PTSD symptom reductions were reported, with high response/remission proportions at one month. • The study is hypothesis-generating rather than confirmatory because it had no blinded control group and only 12 participants.
Why It Matters
As of August 2026, this is directly relevant human psilocybin-PTSD evidence, but it is preliminary and far weaker than the depression/AUD evidence base.
Important Limitation
• Open-label design, no placebo/control group, very small sample and short follow-up. • Veterans with severe treatment-resistant PTSD are a specific population. • Expectancy effects and intensive psychotherapy may have contributed substantially to outcomes.
Psilocybin Produces Substantial and Sustained Decreases in Depression and Anxiety in Patients With Life-Threatening Cancer: A Randomized Double-Blind Trial
Griffiths et al.
2016
51 cancer patients with life-threatening diagnoses and symptoms of depression and/or anxiety.
Randomized double-blind crossover comparison of very low placebo-like psilocybin dose vs high dose, with five weeks between sessions.
What They Found
• High-dose psilocybin produced large decreases in clinician- and self-rated depressed mood and anxiety. • At six months, about 80% continued to show clinically significant decreases in depressed mood and anxiety. • Quality of life, life meaning, optimism and death anxiety measures also improved.
Why It Matters
A second independent landmark 2016 controlled trial supporting the anxiety and end-of-life/serious-illness SEO topics.
Important Limitation
• Cancer-specific sample and crossover design. • Small study by modern confirmatory-trial standards. • Subjective psychedelic effects make blinding difficult.
Rapid and Sustained Symptom Reduction Following Psilocybin Treatment for Anxiety and Depression in Patients With Life-Threatening Cancer: A Randomized Controlled Trial
Ross et al.
2016
29 patients with cancer-related anxiety and depression.
Double-blind placebo-controlled crossover trial: single-dose psilocybin 0.3 mg/kg vs niacin, both with psychotherapy.
What They Found
• Before crossover, psilocybin produced substantial improvements in anxiety and depression compared with niacin. • At 6.5 months, approximately 60%-80% of participants continued to have clinically significant reductions in depression or anxiety. • The study also reported improvements in cancer-related demoralization, hopelessness, quality of life and attitudes toward death.
Why It Matters
One of the two landmark controlled trials supporting anxiety/existential-distress language specifically in people with life-threatening cancer.
Important Limitation
• Small sample and crossover design. • Findings apply to cancer-related psychological distress and should not be generalized directly to generalized anxiety disorder. • The trial used structured psychotherapy and a research protocol.
Percentage of Heavy Drinking Days Following Psilocybin-Assisted Psychotherapy vs Placebo in the Treatment of Adult Patients With Alcohol Use Disorder: A Randomized Clinical Trial
Bogenschutz et al.
2022
95 adults with alcohol use disorder were randomized; 93 were included in the primary analysis.
Double-blind randomized clinical trial of psilocybin vs diphenhydramine active placebo, with psychotherapy in both groups.
What They Found
• During the 32-week double-blind period, heavy drinking days were 9.7% in the psilocybin group vs 23.6% in the active-placebo group. • The adjusted between-group mean difference was 13.9 percentage points, favoring psilocybin. • No serious adverse events among psilocybin recipients were reported in the primary trial.
Why It Matters
The strongest directly relevant controlled study for Satya's alcohol-use SEO page.
Important Limitation
• Psilocybin was delivered with a structured psychotherapy protocol; the study does not isolate drug effect from therapeutic context. • Clinical-trial participants were carefully screened, and results do not automatically generalize to routine services. • One major RCT is meaningful but not the same as a mature evidence base with multiple confirmatory trials.
Psilocybin in the Treatment of Cocaine Use Disorder: A Randomized Clinical Trial
Hendricks et al.
2026
40 adults with cocaine use disorder were randomized; 36 completed assessment through day 180.
Randomized blinded trial comparing psilocybin with placebo in a manualized psychotherapy program.
What They Found
• The trial reported greater cocaine-abstinent days and reduced risk of lapse in the psilocybin group. • The authors characterized the findings as preliminary and called for adequately powered confirmatory trials.
Why It Matters
Useful supplemental evidence that the addiction research is expanding beyond alcohol, but still hypothesis-generating.
Important Limitation
• Small sample, wide confidence intervals, blinding challenges and potential therapist/allegiance effects. • The article itself says findings should be conceptualized as hypothesis-generating rather than confirmatory.
Safety, Tolerability, and Efficacy of Psilocybin in 9 Patients With Obsessive-Compulsive Disorder
Moreno et al.
2006
9 adults with DSM-IV obsessive-compulsive disorder.
Modified double-blind pilot with up to four single-dose psilocybin exposures across dose levels.
What They Found
• The pilot reported acute reductions in OCD symptoms after psilocybin in some participants. • The study established feasibility/safety observations that helped motivate later controlled work.
Why It Matters
Historically important first modern clinical study directly examining psilocybin in OCD.
Important Limitation
• Only nine participants, unconventional design and no adequately powered placebo-controlled efficacy test. • Too small to support broad efficacy claims.
A Randomized Clinical Trial of Repeated Doses of Psilocybin for the Treatment of Obsessive-Compulsive Disorder
Moreno et al.
2026
15 participants with OCD.
Small randomized clinical trial with a blinded initial phase and repeated psilocybin dosing.
What They Found
• The study reported symptom reductions and found repeated dosing generally well tolerated in the research setting. • The authors concluded the approach appears potentially effective but explicitly called for larger trials.
Why It Matters
The most current direct OCD trial in the binder and an important update beyond the 2006 pilot.
Important Limitation
• Extremely small sample; repeated dosing protocol differs from standard Oregon service-center experiences. • Results remain preliminary and are not sufficient for strong public efficacy claims.
Psilocybin Produces Substantial and Sustained Decreases in Depression and Anxiety in Patients With Life-Threatening Cancer: A Randomized Double-Blind Trial
Griffiths et al.
2016
51 cancer patients with life-threatening diagnoses and symptoms of depression and/or anxiety.
Randomized double-blind crossover comparison of very low placebo-like psilocybin dose vs high dose, with five weeks between sessions.
What They Found
• High-dose psilocybin produced large decreases in clinician- and self-rated depressed mood and anxiety. • At six months, about 80% continued to show clinically significant decreases in depressed mood and anxiety. • Quality of life, life meaning, optimism and death anxiety measures also improved.
Why It Matters
A second independent landmark 2016 controlled trial supporting the anxiety and end-of-life/serious-illness SEO topics.
Important Limitation
• Cancer-specific sample and crossover design. • Small study by modern confirmatory-trial standards. • Subjective psychedelic effects make blinding difficult.
Rapid and Sustained Symptom Reduction Following Psilocybin Treatment for Anxiety and Depression in Patients With Life-Threatening Cancer: A Randomized Controlled Trial
Ross et al.
2016
29 patients with cancer-related anxiety and depression.
Double-blind placebo-controlled crossover trial: single-dose psilocybin 0.3 mg/kg vs niacin, both with psychotherapy.
What They Found
• Before crossover, psilocybin produced substantial improvements in anxiety and depression compared with niacin. • At 6.5 months, approximately 60%-80% of participants continued to have clinically significant reductions in depression or anxiety. • The study also reported improvements in cancer-related demoralization, hopelessness, quality of life and attitudes toward death.
Why It Matters
One of the two landmark controlled trials supporting anxiety/existential-distress language specifically in people with life-threatening cancer.
Important Limitation
• Small sample and crossover design. • Findings apply to cancer-related psychological distress and should not be generalized directly to generalized anxiety disorder. • The trial used structured psychotherapy and a research protocol.
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to original sources.
We present evidence
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Research evolves.
We keep this library updated.
Information here is
not medical advice.
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