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Home/Research/Psilocybin/Obsessive-Compulsive Disorder (OCD)

Psilocybin for Obsessive-Compulsive Disorder (OCD)

32 papers and 13 clinical trials exploring psilocybin as a treatment for obsessive-compulsive disorder (ocd).

CompoundClassic Psychedelic

Psilocybin

Psilocybin is a naturally occurring tryptamine psychedelic that acts as a prodrug to psilocin, a potent 5-HT2A receptor agonist. It is the furthest advanced psychedelic in clinical development, with two positive Phase III trials in treatment-resistant depression and expanding regulated access in Australia, Germany, and US states.

Full Psilocybin profile
IndicationAbout 1-2% of the population worldwide.

Obsessive-Compulsive Disorder (OCD)

Recent research indicates that psychedelics, particularly psilocybin, are emerging as potential therapeutic agents in the treatment of Obsessive-Compulsive Disorder (OCD). Early clinical trials demonstrate promising results regarding their efficacy and safety, paving the way for future studies in this field.

Full Obsessive-Compulsive Disorder (OCD) profile

Academic Research

32 papers
Open Accessindividual

Case Report: Repeated low doses of psilocybin reduce perceived symptom severity but fail to restore cognitive flexibility in a case of severe obsessive-compulsive disorder: an observational case study of identical twins

This observational case study of identical twins found that repeated low doses of psilocybin in one twin with severe obsessive-compulsive disorder (OCD) were linked to lower perceived symptom severity and better emotional well-being. However, the affected twin still showed impaired cognitive flexibility compared with the unaffected twin.

Published
April 21, 2026
Journal
Frontiers in Psychiatry
Authors
Drange, S., Cohen, J., Johansen, S. S., Dunkley, B., Palner, M.
Paywallindividual

A randomized clinical trial of repeated doses of psilocybin for the treatment of obsessive–compulsive disorder

This randomised clinical trial (n=15) found that psilocybin (up to 21mg/70kg) given over up to eight weekly sessions was well-tolerated with no serious adverse events, and significantly reduced OCD symptoms compared to placebo, with 73% of participants responding and 40% reaching remission by the end of the 8-week treatment, with meaningful effects still present at 6 months.

Published
March 13, 2026
Journal
Journal of Psychopharmacology
Authors
Moreno, F. A., Allen, K. E., Wiegand, C. B., Dunne, R., Prickett, J. I., Bayze, B., Allen, J. J. B.
Open Accessindividual

Acute and post-dosing effects of single-dose psilocybin for obsessive-compulsive disorder in a randomized, double-blind, placebo-controlled trial: an interpretative phenomenological analysis

Qualitative interviews with 12 participants from a randomized, placebo‑controlled single‑dose psilocybin trial for treatment‑refractory OCD showed that set and setting strongly shaped acute (often partial) perceptual, emotional and metacognitive experiences, which were followed by post‑dosing changes in OCD symptoms, perceptions and behavioural/metacognitive processes. These changes mapped onto putative mechanisms of ERP and ACT, suggesting hypotheses for further study and potential value in integrating psilocybin with structured psychotherapy for OCD.

Published
December 10, 2025
Journal
Frontiers in Psychiatry
Authors
Ching, T. H. W., Stahnke, B., Shnayder, S., Agin-Liebes, G., Adams, T. G., Amoroso, L., Baiz, O., Belser, A., Bohner, C., Burke, M., D’Amico, E., DePalmer, G., Eilbott, J., Fram, G., Grazioplene, R., Hokanson, J., Jankovsky, A., Kichuk, S. A., Martins, B., Purohit, P., Schaer, H., Sierra, Y. P., Witherow, C., Pittenger, C., Kelmendi, B.
Open Accessindividual

Single-dose (10 mg) psilocybin reduces symptoms in adults with obsessive-compulsive disorder: A pharmacological challenge study

This open-label study (n=19) found that 10mg oral psilocybin produced a significant reduction in OCD symptoms compared to 1mg, with a large effect size (Cohen's d = 0.82) one week after dosing, particularly for compulsions rather than obsessions, though effects diminished over subsequent weeks.

Published
October 1, 2025
Journal
Comprehensive Psychiatry
Authors
Pellegrini, L., Fineberg, N. A., O'Connor, S., Pereira De Souza, A. M. F. L., Godfrey, K., Reed, S., Peill, J. M., Healy, C. J., Rohani-Shukla, C., Lee, H., Carhart-Harris, R. L., Robbins, T. W., Nutt, D. J., Erritzoe, D.
Open Accessindividual

Psilocybin’s acute and persistent brain effects: a precision imaging drug trial

This randomised, cross-over study (n=7) used precision functional mapping with high-resolution multi-echo fMRI to characterise psilocybin (25mg) versus methylphenidate effects on brain networks, revealing decreased network modularity during psilocybin exposure and reproducible network changes. Participants showed unique brain configurations and reported stronger mystical experiences with psilocybin compared to methylphenidate.

Published
June 5, 2025
Journal
Scientific Data
Authors
Subramanian, S., Renau, R., Perry, D., Chacko, R., Laumann, T. O., Flavin, K., Horan, C., Schweiger, J., Metcalf, N., Lenze, E. J., Snyder, A. Z., Dosenbach, N. U. F., Nicol, G., Siegel, J. S.
Open Accessindividual

The unique neural signature of your trip: Functional connectome fingerprints of subjective psilocybin experience

Using brain‑fingerprinting on fMRI from volunteers given psilocybin or placebo, the study shows psilocybin increases functional‑connectome idiosyncrasy via greater intersubject dissimilarity and shifts idiosyncratic features from frontoparietal regions to the default mode network (DMN). They identify a DMN‑centred connectivity signature—reduced within‑DMN and DMN‑limbic coupling and increased DMN‑attentional connectivity—that predicts subjective psilocybin experience, demonstrating the value of brain‑fingerprinting for pharmacological neuroimaging.

Published
April 1, 2024
Journal
Network Neuroscience
Authors
Tolle, H. M., Farah, J. C., Mallaroni, P., Mason, N. L., Ramaekers, J. G., Amico, E.

Clinical Trials

13 trials
RecruitingPhase I

Psilocybin Whole Mushroom for the Treatment of Obsessive-compulsive Disorder.

This Phase I, randomised, quadruple-masked trial (n=30) will evaluate the tolerability, safety, subjective experience, and efficacy of repeated administration of three different doses of psilocybin whole mushroom for the treatment of obsessive-compulsive disorder (OCD). Participants aged 18 years and older with moderate to severe OCD will be assigned to receive low (10 mg), medium (20 mg), or high (30 mg) doses of psilocybin, delivered in a chocolate matrix, over a 12-week period. Participants will undergo a preparation session with a study therapist before receiving the psilocybin doses, which will be spaced approximately three weeks apart. They will be monitored for safety during dosing sessions, with vital signs checked hourly, and will complete assessments using the Yale-Brown Obsessive Compulsive Scale and Visual Analogue Scale throughout the treatment and follow-up phases. After the treatment phase, participants will be contacted monthly for ongoing efficacy and safety assessments for a total of 12 months.

Started
March 1, 2026
Type
interventional
Blinding
quadruple
Randomized
Yes
Registry ID
NCT07347405
Not yet recruitingPhase I

A Phase 1, Open-label, Single-arm Basket Trial of the Intravenously Administered Psilocin (TRP-8803): Safety, Anxiety, and Quality of Life Across Health Conditions Characterised by Cognitive Inflexibility, Emotional Distress, and Persistent Bodily Symptom Burden

This Phase 1, open‑label, single‑arm basket trial (N=66) tests the safety and early clinical effects of intravenous psilocin (TRP‑8803) administered in two dosing sessions alongside psychotherapy over a 6‑week treatment period, with a 12‑week follow‑up. Conducted in Australia and sponsored by Tryp Therapeutics, the study enrols participants across ten diagnostic cohorts — anorexia nervosa, body dysmorphic disorder, chronic fatigue, fibromyalgia, generalised anxiety disorder, irritable bowel syndrome, long COVID, major depressive disorder, obsessive–compulsive disorder and post‑traumatic stress disorder — to evaluate tolerability and signals of benefit in anxiety and quality of life. As a Phase 1 trial the primary outcomes focus on safety and tolerability (adverse events, vital signs and treatment‑emergent effects), with secondary or exploratory outcomes assessing changes in anxiety symptoms and health‑related quality of life using standardised, validated instruments. The single‑arm, open‑label design means there is no placebo or active comparator, and efficacy assessments are intended to generate preliminary, hypothesis‑generating data to inform the design of subsequent controlled studies. The study began recruitment in November 2025.

Started
November 3, 2025
Type
interventional
Blinding
none
Randomized
Yes
Registry ID
ACTRN12625000949482
Not yet recruitingPhase I/II

Psilocybin for Treatment of OCD-2

This randomised, double-masked Phase I/II trial (n=20) will study the safety, tolerability, and efficacy of psilocybin (10mg vs 30mg) across four sessions for the treatment of obsessive-compulsive disorder (OCD).

Started
August 1, 2025
Type
interventional
Blinding
triple
Randomized
Yes
Registry ID
NCT06992999
Not yet recruitingPhase I/II

The efficacy of psilocybin assisted psychotherapy (PAP) for treatment resistant obsessive-compulsive disorder (OCD), body dysmorphic disorder (BDD), and anorexia nervosa (AN); a pilot, single-arm basket trial

This single-arm, Phase I/II pilot trial (n=30) will test psilocybin-assisted psychotherapy (25mg x 2 doses, 4 weeks apart) for treatment-resistant obsessive-compulsive disorder (OCD), body dysmorphic disorder (BDD), and anorexia nervosa (AN).

Started
October 1, 2024
Type
interventional
Blinding
none
Randomized
No
Registry ID
ACTRN12624001160527
Enrolling by invitationPhase I

Feasibility, Clinical Effects, and Safety of Psilocybin-assisted Psychotherapy for Treatment-resistant OCD (PAP-OCD)

Open-label, single-group feasibility study (n=10) of two 25 mg psilocybin sessions given two weeks apart with supportive psychotherapy for treatment-resistant OCD.

Started
April 1, 2024
Type
interventional
Blinding
none
Randomized
No
Registry ID
NCT06299319
Not yet recruitingPhase II

Developing Optimal Psychedelic Assisted Psychotherapy for Obsessive-Compulsive Disorder

This interventional randomised, blinded, parallel Phase II trial (n=40) compares MDMA-assisted psychotherapy (3 × 100 mg oral sessions) to psilocybin-assisted psychotherapy (3 × 25 mg oral sessions) for treatment-resistant OCD, with preparatory and integration therapy.

Started
August 1, 2023
Type
interventional
Blinding
single
Randomized
Yes
Registry ID
ACTRN12622001525774

Explore further

Search all Psilocybin papers Search all Obsessive-Compulsive Disorder (OCD) trials Full Psilocybin profile Full Obsessive-Compulsive Disorder (OCD) profile