Psilocybin-assisted Treatment for Cannabis Use Disorder

This pilot study will evaluate the therapeutic potential of psilocybin to produce significant reduction in cannabis use compared to pre-treatment in a sample of 12 treatment-seeking patients with Cannabis Use Disorder (CUD). Upon enrollment, participants will complete a 12-week course of study treatment including two psilocybin sessions, with follow-up assessment 3 and 6 months after the first psilocybin session. After 4 weekly preparatory meetings including a targeted cognitive behavioral therapy (CBT) intervention for CUD, participants will receive a moderately high dose (25mg) of psilocybin in week 5 of the 12-week counseling, and either another moderately high dose (25mg) or a high dose (35mg) in week 7. After each psilocybin session, participants will complete a follow-up meeting within 3 days (i.e. integration meeting), as well as continued weekly meetings through week 12. Participants will complete post-session assessments in approximately weeks 12 (End of Treatment), 17 (3 months after 1st psilocybin session, and 29 (6 months after 1st psilocybin session). Some study meetings may be held virtually via a secure web-based video conference platform (e.g., Zoom). Self-reported cannabis use and biomarkers of recent use will be assessed at baseline (screening), weekly throughout the 12-week intervention, and at approximately weeks 17 (3 months after 1st psilocybin session), and 29 (6 months after 1st psilocybin session).