Psilocybin for Treatment of Obsessive Compulsive Disorder (PSILOCD)
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ClinicalTrials.gov Identifier: NCT03300947 |
Recruitment Status :
Active, not recruiting
First Posted : October 4, 2017
Last Update Posted : February 8, 2023
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Condition or disease | Intervention/treatment | Phase |
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Obsessive-compulsive Disorder (OCD) | Drug: Psilocybin 100 mcg/kg Drug: Psilocybin 300 mcg/kg Drug: Lorazepam 1 mg | Phase 1 |
The study seeks to improve our ability to treat and improve the lives of people who have obsessive-compulsive disorder (OCD) by exploring the benefits of psilocybin, a mind-altering drug that changes activity in brain areas believed to be involved in OCD. Anecdotal reports and results from previous research support this idea. This two-phase study will enroll patients with symptomatic OCD who are not taking mind-altering medications or street drugs.
During Phase One, neither participants nor the investigators will know which drugs or doses are administered. This information will be available if it is medically necessary to reveal which drugs and doses were administered. Five subjects in each group will receive study drug a total of four times, separated by one week. During Phase Two, participants will not know which drugs or doses they receive, but the investigators will know. All participants will receive psilocybin at some point during study participation.
Participants will be randomly assigned to one of the following groups:
- Low dose (100 µg/kg) psilocybin,
- High dose (300 µg/kg) psilocybin, or
- Lorazepam (1 mg), a calming medication. Lorazepam is used often for anxiety and will be used to mask which drug participants receive.
Participants will spend approximately 12 hours at the research site under observation during each visit, until they are free of the mind-altering effects of the drug and are determined by the psychiatrist to be safe to go home accompanied by a responsible adult. The effects of low versus high doses, and the additive effects of repeated doses will be analyzed and will be compared to the effects of lorazepam.
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 15 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Intervention Model Description: | All participants will be randomly assigned to administration of low dose (100 µg/kg) psilocybin, High dose (300 µg/kg) psilocybin, or Lorazepam (1 mg). Eight different sessions divided in two phases will ensure all subjects are exposed to psilocybin at some point during the study in a blinded fashion. |
Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Masking Description: | Phase One: Double blind (both participant AND researchers (In room Care Provider, Investigators, Blinded Outcomes Assessor) Phase Two: Single blind (Participant and Blinded Outcomes Assessor) |
Primary Purpose: | Treatment |
Official Title: | Psilocybin for Treatment of Obsessive Compulsive Disorder |
Actual Study Start Date : | January 2, 2019 |
Estimated Primary Completion Date : | April 30, 2023 |
Estimated Study Completion Date : | May 30, 2023 |

Arm | Intervention/treatment |
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Experimental: High-dose Psilocybin
Psilocybin 300 mcg/kg once per week, every week, for 8 weeks
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Drug: Psilocybin 300 mcg/kg
Psilocybin belongs to the class of hallucinogen or psychedelic drugs. It is one of the major psychoactive components in mushrooms of the Psilocybe genus ("magic mushrooms").
Other Name: Psilocybine, "magic mushrooms" |
Experimental: High- or Low-dose Psilocybin
Psilocybin 100 mcg/kg or psilocybin 300 mcg/kg once per week, every week, for 8 weeks
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Drug: Psilocybin 100 mcg/kg
Psilocybin belongs to the class of hallucinogen or psychedelic drugs. It is one of the major psychoactive components in mushrooms of the Psilocybe genus ("magic mushrooms").
Other Name: Psilocybine, "magic mushrooms" Drug: Psilocybin 300 mcg/kg Psilocybin belongs to the class of hallucinogen or psychedelic drugs. It is one of the major psychoactive components in mushrooms of the Psilocybe genus ("magic mushrooms").
Other Name: Psilocybine, "magic mushrooms" |
Placebo Comparator: High-dose Psilocybin or Lorazepam
Psilocybin 300 mcg/kg or Lorazepam 1 mg once per week, every week, for 8 weeks
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Drug: Psilocybin 300 mcg/kg
Psilocybin belongs to the class of hallucinogen or psychedelic drugs. It is one of the major psychoactive components in mushrooms of the Psilocybe genus ("magic mushrooms").
Other Name: Psilocybine, "magic mushrooms" Drug: Lorazepam 1 mg A medication used to treat anxiety belonging to a class of drugs known as benzodiazepines, which act on the central nervous system to produce a calming effect. This drug works by enhancing the effects of a certain natural chemical in the body (GABA).
Other Name: Ativan, Intensol |
- Treatment-phase effects on Obsessive-Compulsive symptom severity [ Time Frame: weekly Y-BOCS rating prior to ingestion of study drug on Week 1 through 8, and week 9 (follow up week 1) ]Prospective Assessment of YBOCS (Yale-Brown Obsessive Compulsive Scale) score comparing each psilocybin dose and active placebo (Lorazepam).
- Acute Incidence of Treatment Emergent Adverse Events [ Time Frame: At 0, and 24 hours after blinded medication ingestion ]Prospective active inquiry of adverse events with the SAFTEE-GI (Systematic Assessment For Treatment Emergent Events-General Inquiry) comparing each psilocybin dose and active placebo (Lorazepam)
- Duration of Effects on Obsessive-Compulsive symptom severity [ Time Frame: Follow-up assessments will be conducted weekly over the phone weekly (± 3 days) for one month after last dose, monthly (± 7 days) for three months beginning 28 days after last dose, and then once at 6 months after last dose (± 7 days). ]Prospective Naturalistic Assessment of YBOCS (Yale-Brown Obsessive Compulsive Scale) after repeated administration of study drug.
- Long Term Incidence and Duration of Treatment Emergent Psychiatric Adverse Events [ Time Frame: Follow-up assessments will be conducted weekly over the phone (± 3 days) for one month after last dose, monthly (± 7 days) for three months beginning 28 days after last dose, and then once at 6 months after last dose (± 7 days). ]Prospective Assessment with SCID-I (Structured Clinical Interview for DSM-5 Disorders) psychotic screening tool will assess for onset of psychopathology or hallucinogen induced disorders after repeated use.
- Changes in the magnitude of Error Related Negativity (an electroencephalographic biomarker of OCD) assessed by Error-related negativity (voltage) and mid-frontal theta power (time-frequency approach) [ Time Frame: Baseline, and 9-10 hours after ingestion of study dose 1, 4, and 8. ]Prospective Assessment of Error Related brain activity comparing each psilocybin dose and active placebo (Lorazepam).
- Prospective Self-Assessment of Depression Symptoms [ Time Frame: Baseline, 24 hours after each dose during 8 week active phase, and during the follow-up phase (weekly for one month after last dose, monthly for three months beginning 28 days after last dose, and then once at 6 months after last dose. ]Prospective Assessment of Quick Inventory of Depressive Symptomatology (QIDS) Score comparing each psilocybin dose and active placebo (Lorazepam).
- Prospective Clinician-Rated Assessment of Depression Symptoms [ Time Frame: Baseline, 4 weeks, 8 weeks, and during the follow-up phase (weekly for one month after last dose, monthly for three months beginning 28 days after last dose, and then once at 6 months after last dose ]Prospective Assessment of Montgomery-Asberg Depression Rating Scale (MADRS) Score comparing each psilocybin dose and active placebo (Lorazepam).
- Changes in functional connectivity: 1) between the Caudate Nucleus (CN) and Orbital Frontal Cortex (OFC); 2) within the default mode network (DMN). [ Time Frame: Imaging at baseline, and 9-10 hours post ingestion on weeks 1, 4, and 8. YBOCS at baseline and 8 hours after ingestion at weeks 1, 4, and 8. ]Prospective Assessment of Functional Connectivity in CN and OFC and in DMN comparing each psilocybin dose and active placebo (Lorazepam). Also examining whether magnitude of symptom reduction is related to changes in functional connectivity.

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Ages Eligible for Study: | 18 Years to 65 Years (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Have moderate to severe OCD (DSM-5) after diagnostic interview using the Structured Clinical Interview for DSM-5 Research Version (SCID-R).
- Failed at least one adequate attempted routine care treatment.
- Considered safe for independent living
Exclusion Criteria:
- Concurrent psychosis, active substance use disorder, or a personal history of psychosis.
- Medical illness based on physical examination and routine blood testing that may complicate cardiovascular safety or drug metabolism or excretion, such as uncontrolled hypertension, severe cardiac disease, or kidney or liver failure.
- Unstable Chronic Obstructive Pulmonary Disease (COPD) or severe sleep apnea
- Psychiatric comorbidity that may represent an acute risk to their own or others' safety.
- Subjects may not be using antidepressant medication for OCD for at least two weeks before receiving study drug, and they cannot require any sedative, narcotic, or neuroleptic medications on a regular basis. Any of these medications they have taken should have been stopped long enough in the past to allow for their elimination and safe withdrawal prior to starting administration of the study drug. The specific time required will be dependent on the medication the patient was previously receiving.
- Women who are pregnant, breastfeeding, or unwilling/unable to practice medically acceptable birth control during the study.
- Allergy to lorazepam.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03300947
United States, Arizona | |
University of Arizona | |
Tucson, Arizona, United States, 85724 |
Principal Investigator: | Francisco A. Moreno, MD | Professor of Psychiatry and Associate Vice President, Diversity and Inclusion |
Publications of Results:
Responsible Party: | Francisco A Moreno, Associate Vice President, Diversity and Inclusion; Professor, Psychiatry, University of Arizona |
ClinicalTrials.gov Identifier: | NCT03300947 |
Other Study ID Numbers: |
1707613822 |
First Posted: | October 4, 2017 Key Record Dates |
Last Update Posted: | February 8, 2023 |
Last Verified: | February 2023 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Compulsive Personality Disorder Obsessive-Compulsive Disorder Personality Disorders Mental Disorders Anxiety Disorders Lorazepam Psilocybin Hallucinogens Physiological Effects of Drugs Psychotropic Drugs Anticonvulsants Antiemetics |
Autonomic Agents Peripheral Nervous System Agents Gastrointestinal Agents Hypnotics and Sedatives Central Nervous System Depressants Anti-Anxiety Agents Tranquilizing Agents GABA Modulators GABA Agents Neurotransmitter Agents Molecular Mechanisms of Pharmacological Action |