Effects of Repeated Psilocybin Dosing in OCD

This study aims to investigate the effects of repeated dosing of oral psilocybin on obsessive-compulsive disorder (OCD) symptomatology in a randomized, waitlist-controlled design with blinded independent ratings, and assess psychological mechanisms that may mediate psilocybin’s therapeutic effects on OCD.

The treatment protocol for this study can be found here.

Topic Obsessive-Compulsive Disorder
Compound Psilocybin
Country United States of America
Visit trial
Status Not yet recruiting
Results Published No
Start date 01 November 2022
End date 01 November 2026
Chance of happening 89%
Phase Phase I
Design Blinded
Type Interventional
Generation First
Participants 30
Sex All
Age 21- 65
Therapy No

Trial Details

Aim 1: To examine the effects of two doses of psilocybin on OCD symptoms among participants in the immediate treatment condition, compared to participants in the waitlist control/delayed treatment condition. The investigators hypothesize that participants in the immediate treatment group will report statistically significantly greater symptom improvement from baseline 4 days post-second dose, compared to participants in the waitlist control/delayed treatment group at the same interval during their waitlist phase. Aim 2: To examine the effects of two doses of psilocybin on OCD symptoms, compared to one dose. The investigators hypothesize that two doses of oral psilocybin will reduce OCD symptoms to a statistically significantly greater extent than one dose. This study aims to investigate the effects of repeated dosing of oral psilocybin on OCD symptomatology and assess psychological mechanisms that may mediate psilocybin's therapeutic effects on OCD. This study will employ a randomized, waitlist-controlled design with blinded independent ratings, with participants randomized to receive either immediate treatment (two doses oral psilocybin separated by one week) or delayed treatment (7 weeks post-randomization). An adaptive dose selection strategy will be implemented, with the first dose being standardized at 25 mg of psilocybin, and the second dose being either the same or a higher dosage (i.e., 30 mg) on the basis of a clinically significant response from baseline or not, respectively, 4 days post-first dose. This study is conducted entirely on an outpatient basis with the possibility of remote/virtual follow-up visits after each dosing session. The dosing sessions last the entire day, and participants will be medically cleared prior to being permitted to return home with assistance (e.g., driven by a family member or friend, or ride share).

NCT Number NCT05370911

Sponsors & Collaborators

Yale University
The Yale Psychedelic Science Group was established in 2016.

Measures Used

Yale-Brown Obsessive Compulsive Scale
The Yale Brown Obsessive-Compulsive Scale (Y-BOSC) is considered the gold-standard to assess OCD severity. The scale consists of ten items and measures the severity and type of symptoms in people with OCD over the previous seven days. The scale is used at initial diagnosis as well as during follow up sessions after treatment. The scores range from 0 to 4, with higher scores indicating greater symptoms of OCD severity.

Data attribution

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