Psilocybin Intervention for Veterans Overcoming Treatment-Resistant Depression

Treatment-resistant depression (TRD) is a serious mental health problem in Veterans, frequently comorbid with post-traumatic stress disorder (PTSD), and in need of novel and effective treatments. Clinical studies have revealed antidepressant effects of psilocybin for depression in civilians, but less is known about its efficacy and safety in Veterans. Very limited data is available on the effects of psilocybin in the treatment of PTSD. Thus, it is important to evaluate the safety and efficacy of psilocybin in the treatment of TRD with and without PTSD among Veterans. The purpose of this multi-site, double-blind, randomized controlled trial is to evaluate the efficacy and risks of psilocybin for the treatment of TRD in U.S. military Veterans with and without (±) concurrent PTSD. Eligible and consenting Veterans will two psilocybin dosing sessions along with preparation, administration, and integration psychological support provided by a facilitator. For the 1st psilocybin administration, participants will be randomized to one of two doses under blinded conditions. One month later, all participants will receive the same dose at their 2nd psilocybin visit. Outcomes will be measured by an independent evaluator masked from all treatments at 2 and 4 weeks after each dosing session. Longer-term follow-up will be conducted over 6 months. Both expected and unanticipated adverse events will be collected by type, severity and relatedness to the study drug.