The U.S. Food and Drug Administration (FDA) rejected on Sunday a request by a pharmaceutical company to approve MDMA (commonly known as Ecstasy) as a treatment for post-traumatic stress disorder (PTSD).

The decision follows recommendations by the agency's advisory committee held in June, which concluded there wasn't enough evidence to prove that the treatment was safe or effective. Lykos Therapeutics, the company behind the treatment, announced last Friday the FDA had decided not to approve their therapy. However, various experts believe the future of using psychedelic substances to treat certain mental health conditions remains promising.

3 View gallery ( Photo: Shutterstock ) NBC reported that the FDA faced intense political pressure to approve the drug. Had it been approved; it would’ve marked the first new treatment for PTSD in over two decades. Lykos Therapeutics had sought FDA approval for the drug as part of a therapy protocol that included counseling sessions.

The approval would have made MDMA the first psychedelic substance regulated by U.S. authorities.

The decision is a disappointment for many researchers and patients who were hopeful for advancements in PTSD treatment. The FDA advisory committee highlighted several concerns, including allegations of inappropriate sexual behavior during a clinical trial and the potential for severe health risks after taking the drug, such as heart problems and dangers of misuse. An FDA scientific review, published before the advi.