Psilocybin-assisted Therapy for Post-Traumatic Stress Disorder in Survivors of Intimate Partner Violence

The goal of this randomized controlled trial is to evaluate the efficacy of psilocybin administered with Acceptance and Commitment Therapy (ACT) as an intervention to reduce post-traumatic stress disorder (PTSD) symptom burden in adult (aged 18-65) survivors of intimate partner violence (IPV). This trail will test the following 2 aims: AIM 1 : To compare the efficacy of a therapeutic psilocybin dose at improving outcomes on the PCL-5 and CAPS-5 as compared to an active control psilocybin dose in IPV survivors with chronic PTSD. AIM 2: To evaluate the efficacy of psilocybin on quality of life, cognitive function, motor ability, depression, anxiety, and cognitive flexibility. Participants will be asked to: * Complete a 2 part screening process * Attend a baseline assessment * Complete a psychoeducation preparation session(s) * Attend psilocybin administration session (receive high dose \[25mg\] or low dose psilocybin \[1mg\]) * Complete 5-6 weekly sessions of ACT * Repeat outcome measures at 1-week, 4 weeks, 3 months (online questionnaires only), and 6 months post-psilocybin administration.