A new study shows that MDMA — a chemical compound with psychedelic properties, otherwise known as Ecstasy or Molly — helped those suffering from severe post-traumatic stress disorder when paired with talk therapy, The New York Times reports.

The study — which was led by researchers at the University of California, San Francisco and will be published in Nature Medicine this month — boasts a pretty small sample size of just 90 people (the participants included military combat veterans, first responders, and victims of sexual assault, mass shootings, domestic violence, and childhood trauma). But it found that those who took MDMA during therapy saw a greater reduction in their symptoms compared with those who took a placebo. Two months after treatment, 67 percent of the MDMA group no longer qualified for a PTSD diagnosis, while only 32 percent of the placebo group did.

“This is a wonderful, fruitful time for discovery, because people are suddenly willing to consider these substances as therapeutics again, which hasn’t happened in 50 years,” said Jennifer Mitchell, a UCSF neuroscientist and the study’s lead author.

The study, which was sponsored by the Multidisciplinary Association of Psychedelic Studies (MAPS), was the first Phase 3 trial conducted using psychedelic-assisted therapy, and could further boost efforts to explore the therapeutic benefits of other psychedelics like psilocybin, LSD, and mescaline. Additional research needs to be done on MDMA, however, before it can be approved for therapeutic use by the Food and Drug Administration. A second Phase 3 trial is currently underway with 100 participants, and it’s possible approval could come by 2023.

The study does not say that taking MDMA on its own has any particular therapeutic benefit. But Mitchell said the combination of MDMA and therapy appears to allow the brain to better process painful memories and heal itself. Meanwhile, traditional pharmaceuticals tend to just target and dampen symptoms of PTSD.

The medical possibilities of MDMA first emerged in the late-Seventies and early-Eighties, but that work was cut short when the Drug Enforcement Administration criminalized it in 1985. Some underground work quietly continued in the following decades, but only recently were proper studies allowed to start up again.

While this new study highlights the therapeutic possibilities of MDMA, researchers are still trying to figure out the exact science behind it. As is widely known, MDMA boosts serotonin, oxytocin, and dopamine to create feelings of euphoria, empathy, trust, and compassion; in a therapeutic context, it also seems capable of re-opening what neuroscientists call the “critical period” — a moment in childhood where the brain is capable of making and storing new memories.

For instance, one subject in the UCSF study was Scott Ostrom, who had suffered from PTSD since returning from his second deployment in Iraq in 2007. Over the course of his sessions with MDMA, Ostrom said he encountered a spinning black ball with layers that slowly fell away, and at the center was the moment he “became the person I needed to be to serve that combat deployment.” Ostorm said he was able to engage with his PTSD alter ego and eventually grant his actual self permission to return.

“The reason I like calling this medicine is it stimulated my own consciousness’s ability for self-healing,” Ostrom said. “You understand why it’s OK to experience unconditional love for yourself.”