Not Yet RecruitingPhase 1/2

Psilocybin for Treatment of OCD-2

United States20 participantsStarted 2026-09-08

Plain-language summary

Previous research indicates that psilocybin, a drug that changes activity in brain areas believed to be involved in obsessive-compulsive disorder (OCD), might improve treatment for, and improve lives of, people diagnosed with OCD. The investigators propose to study 20 patients with symptomatic OCD who are not taking mind altering medications or street drugs, to participate in a 12 week study. Participants will be assigned (by luck of the draw) to take low or high dose psilocybin in four dosing sessions separated by 3 weeks. Measurements for the severity of OCD, ability to function, perception of quality of life, safety and tolerability will be measured at baseline prior to drug administration, during the dosing periods, and at the end of study. Other measurements will include brain imaging via fMRI and brain tracing via electroencephalogram (EEG). The investigators believe that during medically supervised dosing sessions, both doses of psilocybin will be safe and well tolerated, and will reduce OCD symptoms. Because psilocybin is a potent drug and especially at the higher dose may induce altered states of consciousness, a thoughtfully implemented procedure for participant safety is in place. Information will be obtained to explore the effects of altered states of consciousness in the outcome of treatment and to find the mechanism of benefit.

Who can participate

Age range

18 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Aged 18 years old, and older * Have OCD (DSM-5) based on diagnostic interview using the Structured Clinical Interview for DSM-5 Research Version (SCID). * At least moderate severity: Yale-Brown Obsessive-Compulsive Scale (YBOCS) score ≥16. * Failed at least one adequate trial of guideline concordant treatment. * Considered safe for independent living * Subjects must discontinue use of any of the following prescription or over the counter (OTC) products or nutritional supplements at least two weeks prior to initiating double-blind treatment: * Monoamine oxidase (MAOI), UGT1A10, and UGT1A9 inhibitors * Other active OCD treatments (cognitive behavioral therapy \[CBT\] or other psychotherapy; electrical or magnetic device treatments; pharmacological treatments such as antidepressant medications (e.g., SSRIs, SNRIs, MAOIs, TCAs, 5HT2 blockers, NERIs, etc.), lithium, antipsychotic drugs, 5-HT2 antagonists such as pimavanserin, and glutamatergic acting medications) * Note that fluoxetine must be discontinued at least 6 weeks prior to initiating double-blind treatment. * 5HT2 agonists (e.g., efavirenz, lorcaserin), which may alter the response to psilocybin * Serotonin-acting dietary supplements (e.g., 5-hydroxy-tryptophan, St. John's wort) due to potential for interaction with psilocybin and increased safety risks Exclusion Criteria: * Concurrent active substance use disorder, or a personal history of psychosis. * History of psychosis among first degree r…

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Safety and tolerability of orally administered psilocybin

Timeframe: 12 months

Trial details

NCT IDNCT06992999

SponsorFrancisco A Moreno

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2028-12

Contact for this trial

Esmeralda Terrazas

(520) 626-8000 esmeralda97h@arizona.edu

View on ClinicalTrials.gov More Obsessive - Compulsive Disorder trials