Evaluation of Psilocybin-assisted Psychotherapy (PaP) for the Treatment of Post-traumatic Stress Disorder (PTSD) in Military Veterans

Recent studies have shown that Psilocybin-Assisted Psychotherapy (PaP) for individuals with treatment-resistant depression can result in outcomes that exceed routine psychotherapy. Psilocybin may have a catalytic effect on the psychotherapeutic process, enhancing introspection and interoception. PaP may similarly benefit the treatment of posttraumatic stress disorder (PTSD). Research indicates high treatment drop-out rates (approximately 30%) among PTSD patients, and moderate remission rates (approximately 44%) 40 months after completing treatment. Furthermore, some veterans with PTSD have poorer treatment responses than members of the general public. This suggests that alternative treatment approaches may be required to support veterans who do not benefit from standard evidence-based approaches. This study aims to explore the acceptability, feasibility, safety and efficacy of PaP for veterans with PTSD. A total of eight military veterans will be recruited. The study involves two non-directive preparatory sessions, two dosing sessions of psilocybin, followed by 12 sessions of Cognitive Processing Therapy. It is hypothesised that PaP will result in a significant reduction in PTSD symptoms, as indicated by PTSD Checklist for Diagnostic and Statistical Manual of Mental Disorders (DSM-5; PCL-5) scores from baseline to one-month follow-up.