The psychedelic drug MDMA, also known as ecstasy or molly, has passed another key hurdle on its way to regulatory approval as a treatment for mental illness. A second large clinical trial has found that the drug in combination with psychotherapy " is effective at treating post-traumatic stress disorder (PTSD). In June, Australia became the first country to allow physicians to prescribe MDMA for treating psychiatric conditions. MDMA is illegal in the United States and other countries because of the potential for its misuse. But the Multidisciplinary Association for Psychedelic Studies (MAPS) ... has long been developing a proprietary protocol for using MDMA as a treatment for PTSD and other disorders. MAPS has been campaigning for its legalization. In 2021, researchers sponsored by MAPS reported the results of a study in which 90 people received a form of psychotherapy developed by the organization alongside either MDMA or a placebo. After three treatment sessions, 67% of those who received MDMA with therapy no longer qualified for a PTSD diagnosis, compared with 32% of those who received therapy and a placebo. The results of a second trial ... were similar: 71% of people who received MDMA alongside therapy lost their PTSD diagnosis. A MAPS spokesperson says that the organization plans to seek formal FDA approval before the end of this year, and that because the agency has already designated MDMA as a 'breakthrough therapy' ... it will be evaluated quickly.