BACKGROUND: Psilocybin has demonstrated promise for improving depressive symptoms in treatment-resistant depression, but its effects on anxiety, quality of life, functioning, and posttraumatic stress symptoms are less well studied. This study reports exploratory findings from an open-label trial in Veterans with TRD.
METHODS: Participants received a single 25-mg dose of psilocybin administered with psychological support. The primary endpoint was assessed 3 weeks post-dose, with follow-up extending to 12 months. Outcomes included anxiety severity (GAD-7), quality of life (Q-LES-Q-SF), functional impairment (WSAS), and posttraumatic stress disorder symptoms (PCL-5). Experiential outcomes were measured with the Mystical Experience Questionnaire (MEQ), Challenging Experiences Questionnaire (CEQ-30), and Emotional Breakthrough Inventory (EBI). Mixed-effects models were used to evaluate longitudinal changes, and correlation analyses examined associations between measures and changes in depressive symptoms on the Montgomery-Åsberg Depression Rating Scale.
RESULTS: Fifteen participants were included, with ten completing long-term follow-up. GAD-7 scores demonstrated sustained improvements through 12 months, with a 59% reduction from baseline at Week 3. Q-LES-Q-SF gains were significant through Week 12, with a 24% increase at Week 3, and WSAS improvements persisted through Month 6 before declining, with a 46% reduction at Week 3. These effects were no longer statistically significant after accounting for improvements in depression. Unadjusted PCL-5 reductions were observed at all timepoints. Exploratory analyses of acute subjective experiences did not correlate to treatment response.
LIMITATIONS: This study is limited by its small sample size and open-label design.
CONCLUSIONS: Psilocybin with psychological support was associated with improvements in anxiety, quality of life, functioning, and PTSD symptoms which largely correlated to concurrent improvements in depressive symptoms.
CLINICAL TRIAL: NCT04433858.
Psychedelic Science