When the Food and Drug Administration (FDA) declined to approve MDMA-assisted psychotherapy as a treatment for post-traumatic stress disorder (PTSD) last year, the details of its objections were not publicly known. Last week, more than a year after that decision, the FDA clarified its reasoning by publishing the full text of its "complete response letter" to Lykos Therapeutics, the company that submitted the drug application.
The research that the FDA considered was spearheaded by the Multidisciplinary Association for Psychedelic Studies (MAPS), which created Lykos to market MDMA as an FDA-approved medication. On their face, the results from the two Phase 3 clinical trials were impressive.
The first study, published by Nature Medicine in 2021, involved 90 subjects with "severe PTSD," as measured by the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5). That questionnaire is designed to assess problems such as "intrusive distressing memories," hypervigilance, an exaggerated startle response, sleeplessness, difficulty in concentrating, avoidance of cues associated with a traumatic event, and "feelings of detachment or estrangement from others." The second study, reported in the same journal two years later, involved 104 subjects with "moderate to severe PTSD."
