Phase 2 Pilot Safety Study of MDMA-assisted Therapy for Social Anxiety in Autistic Adults

This double-blind, randomized, placebo-controlled exploratory pilot study assessed the safety and feasibility of 3,4-methylenedioxymethamphetamine (MDMA)-assisted therapy for social anxiety in MDMA-naïve adults on the autism spectrum. Each of the 12 subjects participated in two blinded experimental sessions, assisted by either MDMA (75 mg to 125 mg) or placebo, which lasted seven hours. Before experimental sessions, participants underwent three separate hour-long preparatory sessions to learn what to expect and complete pre-treatment assignments. After each experimental session, participants underwent three separate hour-long integrative sessions to help integrate their experiences and insights from the experimental sessions. Subjects assigned to the MDMA group received two of three different doses, either 75 mg, 100 mg, or 125 mg MDMA. Overall, eight subjects were randomized to the MDMA group and four subjects were randomized to the placebo group. Observations before, during, and after experimental sessions were compared between these groups. The main objective of this study was to collect safety data to examine whether MDMA-assisted therapy was tolerated and to estimate symptom reduction in social anxiety and other psychiatric symptoms. The primary outcome measure was change in social anxiety symptoms as measured by the Liebowitz Social Anxiety Scale (LSAS) \[Heimberg et al., 1999\].