The Food and Drug Administration (FDA) has approved the use of MDMA in large-scale trials as a treatment for post-traumatic stress disorder (PTSD).
Small scale studies have previously used the drug, also known as the party-drug ecstasy, to alleviate some of the symptoms of PTSD.
As reported by the New York Times, the FDA green lit a Phase 3 clinical trial, which is significant as it marks the final stage of testing before it can be submitted for approval as a prescription drug.
Dr Charles R. Marmar, the head of psychiatry at New York University's Langone School of Medicine and a leading PTSD researcher, told the Times that he was "cautious but hopeful".
Study participants have previously reported significant improvements in their condition following a course of MDMA therapy, and researchers have been optimistic about the future of the drug as a form of treatment.
"If they can keep getting good results, it will be of great use," Marmar said. However, he also voiced some caution, which was echoed by other reactions to the FDA's approval. "It's a feel-good drug, and we know people are prone to abuse it," he said.
According to the Times, the Multidisciplinary Association for Psychedelic Studies, a small nonprofit created in 1985 to advocate the legal medical use of MDMA, LSD, marijuana and other banned drugs, sponsored six Phase 2 studies treating a total of 130 PTSD patients with the stimulant. It will also fund the Phase 3 research, which will include at least 230 patients.
Two trials in Charleston focused on treating combat veterans, sexual assault victims, and police and firefighters with PTSD who had not responded to traditional prescription drugs or psychotherapy. Patients had, on average, struggled with symptoms for 17 years.
After three doses of MDMA administered under a psychiatrist's guidance, the patients reported a 56 percent decrease of severity of symptoms on average, one study found. By the end of the study, two-thirds no longer met the criteria for having PTSD. Follow-up examinations found that improvements lasted more than a year after therapy, the Times reported.
"We can sometimes see this kind of remarkable improvement in traditional psychotherapy, but it can take years, if it happens at all," said Dr Michael C Mithoefer, the psychiatrist who conducted the trials here. "We think it works as a catalyst that speeds the natural healing process."
The researchers are so optimistic that they have applied for so-called breakthrough therapy status with the Food and Drug Administration, which would speed the approval process. If approved, the drug could be available by 2021.