Psilocybin-Assisted Massed Cognitive Processing Therapy for Chronic Posttraumatic Stress Disorder: An Open-label Trial

This is an open-label trial evaluating feasibility, tolerability, safety and efficacy of psilocybin assisted cognitive processing therapy for chronic Posttraumatic Stress Disorder (PTSD). Current front-line treatments for Posttraumatic stress disorder (PTSD) are ineffective for up to half of patients, with serious medical and societal consequences. It is imperative to improve the efficacy of front-line treatment options, such as cognitive processing therapy (CPT). CPT is an effective treatment for PTSD, including when delivered intensively (i.e., multiple sessions over 7 days). However, a substantial proportion of patients continue to meet criteria for PTSD or have residual PTSD symptoms post-treatment. Psilocybin-assisted CPT may be a potential solution, as preliminary evidence supports the potential of psilocybin to alleviate symptoms of PTSD. Fifteen participants will receive a single dose of psilocybin 25mg combined with 12 sessions of massed CPT, and 2 psychotherapy sessions related to psilocybin over 7 days. Participants will complete clinician-administered scales, self-reported mental health questionnaires, and use a wearable device. After the 1-week interventional period, participants will enter a 12-weeks follow-up period.