A newly published systematic review titled on psilocybin’s effects on obsessive‑compulsive behaviours provides an up-to-date synthesis of research into the compound’s potential for treating OCD and related disorders.
The study integrates findings from both animal models and early human trials, drawing attention to a consistent signal: reductions in obsessive or compulsive behaviours following psilocybin administration.
The review shows that in preclinical models (for example mice with altered grooming behaviours) psilocybin (or its active metabolite) produced marked reductions in compulsive-like behaviours, sometimes lasting beyond the immediate administration period.
Clinically, although data remain limited, participants in early trials or case reports experienced rapid reductions in symptom severity (for example within hours or days) after single doses. The authors emphasise that while the mood-disorder applications of psilocybin are more advanced, this compulsive-behaviour indication is an important frontier.
In humans, single doses of psilocybin led to rapid symptom reductions. For example, in an open‑label study of nine treatment‑resistant OCD patients, reductions of 23 % to 100 % on the Y‑BOCS scale were recorded between 4 and 24 hours after dosing. A pilot trial in body dysmorphic disorder (a related OCRD) using a 25 mg psilocybin dose reported sustained improvements over 12 weeks in 58.3 % of participants.
Mechanistically, the review highlights that psilocybin’s effects on compulsivity may not map exactly onto its classic psychedelic mechanism (5-HT₂A receptor activation). Some animal data suggest alternate or additional pathways (for instance 5-HT₇ receptor involvement, synaptic protein modulation) may underpin the anti-compulsive outcomes. The authors call for more robust, placebo-controlled human trials, ideally with neuroimaging and circuit-level biomarkers, to validate these early signals and clarify therapeutic protocols.
The authors of the review emphasise that while the findings are promising, the evidence remains early stage. Key limitations include small clinical sample sizes, lack of placebo‑controls, short follow‑up intervals and heterogeneity in doses and models. They call for larger, double‑blind, placebo‑controlled trials incorporating neuroimaging of fronto‑striatal circuits, to more precisely map psilocybin’s effect in OCRDs.
The authors propose that psilocybin may one day serve as a treatment for disorders characterised by repetitive, intrusive behaviours, not just mood disorders.
Are companies developing psilocybin-based treatments for OCD?
Several biotechnology companies are advancing psilocybin-based therapies for obsessive-compulsive disorder (OCD), signalling growing clinical interest in this area.
Ceruvia Lifesciences has received U.S. FDA approval for an Investigational New Drug application to begin a Phase 2 trial using its synthetic psilocybin compound, SYNP-101, for OCD. The multicentre, randomised, double-blind, placebo-controlled study will administer a single oral dose and monitor participants for 12 weeks to assess symptom reduction, making it one of the most advanced OCD-focused psilocybin programmes.
Filament Health is developing PEX010, a botanical psilocybin drug exported to Israel for a trial investigating treatment-resistant OCD and PTSD.
MycoMedica Life Sciences lists OCD among its target indications, though its programmes remain early stage, while Compass Pathways is exploring broader psychiatric uses for COMP360, including potential applications in OCD.
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