Psilocybin-assisted psychotherapy for treatment-resistant obsessive–compulsive disorder: protocol for an open-label pilot study
BJPsych Open December 15, 2025 Nicole Ledwos, Jenna Baer, Muhammad Ishrat Husain et al. 2 citations
Up to 60% of people with obsessive–compulsive disorder (OCD) do not respond to standard treatments such as selective serotonin reuptake inhibitors, antipsychotic augmentation, or cognitive–behavioural therapy. This open-label pilot trial will test whether a single 25 mg dose of psilocybin combined with psychological support is feasible, tolerable, and safe for ten adults with treatment-resistant OCD. Clinical improvement will be measured with the Yale–Brown Obsessive–Compulsive Scale. Exploratory brain imaging, electroencephalogram, and transcranial magnetic stimulation-electroencephalogram measures will examine changes in dynamic connectivity and brain dynamics before, during, and up to one week after dosing. Results will inform the design of larger randomized trials and help clarify neurobiological mechanisms of psilocybin-assisted therapy.