Symptoms include reliving traumatic experiences and difficulty sleeping.
Michael Mithoefer is recruiting participants for a clinical trial, which combines psychotherapy and MDMA.
According to ClinicalTrials.gov the study should be completed by February of 2017.
In total, Mithoefer is conducting four studies.
Although the FDA cannot disclose information on drugs being developed a spokeswoman says "Some studies have been permitted to proceed.
They are held to the same standards as other drugs considered for FDA approval."
According to the New York Times, researchers are so optimistic about the new study they applied for breakthrough therapy status, which could speed up the approval process.
If approved, the drug could be available by 2021.
The Multidisciplinary Association for Psychedelic Studies is sponsoring the study.
They also advocated for the legal medical use of LSD, marijuana and other restricted drugs.
Right now MDMA is classified as a Schedule 1 Drug, meaning it has no therapeutic use and a large risk of abuse.