Single-group mechanistic feasibility study (n=19) administering up to 10 mg psilocybin (COMP360) on two occasions to people with OCD to assess cognitive inflexibility, neuroplasticity, and symptom changes.
This within-subjects study administers up to 10 mg psilocybin on two dosing days separated by four weeks to participants meeting DSM-5 criteria for OCD; dosing is supervised medically with psychological support from two therapists.
Participants receive virtual preparation and integration sessions before and after each dosing day; cognitive tasks, acute EEG, and blood sampling assess neuroplasticity and inflammatory markers, with symptom ratings (Y-BOCS, MADRS) performed by a blinded external psychiatrist.
Outcomes focus on changes in cognitive flexibility, decision-making, peripheral neuroplasticity and inflammation markers, EEG measures, and OCD symptom trajectory across the dosing schedule.
All participants received 1 mg oral psilocybin first, then 10 mg oral psilocybin 4 weeks later, in fixed order.
COMP360; fixed sequence of 1 mg followed by 10 mg, separated by 4 weeks.