Investigational psilocybin treatment for post-traumatic stress disorder: a qualitative study of participant experience, trauma engagement, and differences from standard treatment.

Psilocybin treatment for post-traumatic stress disorder, when delivered with standardized preparation and support, may allow patients to engage with trauma-related material indirectly through affective, somatic, and self-transcendent experiences, such as feelings of unity or dissolution of self, rather than requiring direct confrontation with traumatic memories as in standard therapies. This qualitative study, nested within a phase 2 trial involving 21 adults with PTSD, identified four core themes: non-pharmacological factors for psychological safety and trust, the experiential nature of psilocybin treatment, engagement with trauma-related material, and comparative reflections on prior therapies. The findings suggest psilocybin offers a meaningful therapeutic opportunity, but larger controlled studies are needed.

Study at a glance

Abstract

Post-traumatic stress disorder (PTSD) is a debilitating condition leading to significant personal and societal burden. Standard treatments frequently demonstrate limited efficacy, leading to persistent symptoms and high dropout rates. Psilocybin has shown promise in treating depression, a condition that is often comorbid with PTSD. We aimed to explore participant experiences of psilocybin treatment for PTSD, emphasising the role of monitoring and support for safety, direct and indirect engagement with trauma-related material during psilocybin treatment, and differences between psilocybin and standard treatments. This qualitative study was nested within a quantitative, open-label phase 2 trial assessing the safety and tolerability of COMP360 psilocybin in adults with PTSD. Eligible participants were adults (18 years or older) who met Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnostic criteria for PTSD secondary to a traumatic event experienced in adulthood. Recruitment was conducted at three sites across two countries: two in the United States and one in the United Kingdom. Enrolled participants underwent standardised preparation, a single psilocybin administration session, and follow-up integration sessions. Semi-structured interviews were conducted before, the day after, and 12 weeks post-treatment. Data were analysed using reflexive thematic analysis, which is a distinct and theoretically grounded approach to co-construction of recurring themes pertaining to participants' preparedness for treatment, how participants' index trauma presented during treatment, and how psilocybin compared to standard treatments. The quantitative phase 2 trial, which the present qualitative study is nested within, is registered with ClinicalTrials.gov, NCT05312151. Between June 10, 2022, and Feb 12, 2024, 21 participants were enrolled and participated in this qualitative sub-study and completed the in-person qualitative interviews. The analysis revealed four core themes: (1) non-pharmacological factors for psychological safety and trust, (2) the experiential nature of psilocybin treatment, (3) engagement with trauma-related material during psilocybin treatment, and (4) comparative reflections on prior therapies and psilocybin treatment. Emphasising safety, treatment education, and informed consent, the treatment facilitated an experience of both direct and indirect engagement with trauma-related material during psilocybin treatment. Unlike standard treatments requiring direct confrontation with trauma memories, psilocybin appears to enable a broader, indirect engagement with traumatic material via a range of affective, somatic and self-transcendent experiences (e.g., moments of perceived unity, dissolution of self, or felt connection with a larger whole). Our qualitative findings suggests that psilocybin treatment, when administered with standardised preparation and treatment support, may offer a meaningful therapeutic opportunity for Patients with PTSD. Future work should include larger controlled studies and use mixed methods to explore how symptom change, functional outcomes, and patient narratives interact. Compass Pathways, plc.