Heliyon
December 1, 2022
Benjamin Kelmendi, Giuliana DePalmer, Gayle Maloney et al.
34 citations
A patient with treatment-resistant obsessive-compulsive disorder received psilocybin and was followed for a year. His OCD symptoms markedly improved, with the YBOCS score dropping from 24 to between 0 and 2. Broader gains included better emotional connection, social and work functioning, and quality of life. This individual was an early participant in an ongoing controlled study. The results are preliminary but suggest that carefully monitored and supported psychedelic treatment may hold therapeutic potential for obsessions and compulsions.
Frontiers in Psychiatry
April 25, 2023
Rachael Grazioplene, Calvin Bohner, Giuliana DePalmer et al.
27 citations
A randomized, double-blind, placebo-controlled trial tests whether a single dose of psilocybin (0.25 mg/kg) is safe, tolerable, and effective for obsessive-compulsive disorder (OCD) symptoms. Thirty adults who have not responded to at least one standard treatment will receive either psilocybin or an active placebo (niacin). OCD symptoms are assessed by blinded raters at 48 hours post-dosing, with 12 weeks of follow-up. Resting-state neuroimaging explores neural mechanisms. The study aims to provide preliminary evidence for psilocybin's effects on OCD and pave the way for future research on neurobiological mechanisms.
October 5, 2022
Terence H. W. Ching, Stephen A. Kichuk, Giuliana DePalmer et al.
5 citations
preprint
A single 0.25 mg/kg dose of psilocybin, given with non-directive psychological support in a controlled clinical setting, is being tested for safety and efficacy in treating obsessive-compulsive disorder. Monitors accompany participants before, during, and after dosing to prepare them, ensure safety, and provide an unstructured context for processing the experience. Although no formal therapy is delivered, the supportive presence of monitors may be experienced as therapeutic. This manual outlines monitor activities across the three phases of the dosing session.
SSRN Electronic Journal
January 1, 2026
Ben Kelemndi, Thomas Adams, Terence H. W. Ching et al.
1 citation
A single dose of psilocybin (0.25 mg/kg) produced rapid, clinically meaningful, and sustained reductions in obsessive-compulsive disorder (OCD) symptoms among adults with treatment-resistant OCD. In a randomized, double-blind, placebo-controlled trial, the psilocybin group showed a 9.76-point decrease on the A-YBOCS at 48 hours, compared to a 0.07-point increase in the niacin group. At one week, 69.2% of psilocybin participants achieved a response (≥35% symptom reduction) versus 0% of niacin participants. Benefits persisted through 12 weeks. One serious adverse event (suicidal ideation) occurred; no treatment-related deaths were reported.
January 15, 2026
Benjamin Kelmendi, Thomas G. Adams, Terence H. W. Ching et al.
preprint
A single dose of psilocybin (0.25 mg/kg) produced rapid and sustained reductions in obsessive-compulsive disorder (OCD) symptoms among adults with treatment-resistant OCD. In a randomized, double-blind trial, 28 adults received either psilocybin or niacin (250 mg). At 48 hours, OCD severity scores dropped by about 10 points more in the psilocybin group than in the niacin group, a large effect. At one week, 69% of psilocybin participants achieved a clinically meaningful response, compared with none in the niacin group. Benefits lasted through 12 weeks. One serious adverse event occurred. Open-label psilocybin given later also reduced symptoms. The findings suggest psilocybin may offer a new treatment approach for treatment-resistant OCD, but larger confirmatory trials are needed.