A recent study randomly assigned 90 people with severe Post Traumatic Stress Disorder (PTSD) to treatment with either MDMA or placebo, under clinical supervision.
Researchers from the University of California found the group that took MDMA (ecstasy) had a greater reduction in PTSD symptoms over the course of 18 weeks.
The group of people were long-term suffers of PTSD, a type of anxiety disorder triggered by traumatic events such as an assault or an accident.
PTSD symptoms can include flashbacks to the traumatic event and nightmares.
Standard treatments for PTSD include medications and various psychotherapies, however University of Otago professor, Paul Glue, said up to 70 percent of patients may not respond.
The research was sponsored by Multidisciplinary Association for Psychedelic Studies (MAPS), a US-based non-profit organisation which sponsors development of MDMA for PTSD.
Researchers also found the experiment to be safe and well-tolerated.
The subjects were given three doses of MDMA or placebo, paired with three sessions of talk therapy.
Researchers saw a robust reduction in symptoms, even in people who had conditions that make PTSD harder to treat - like childhood trauma and depression.
According to the phase 3 clinical trial published in Nature Medicine, MDMA may return the brain to a place which is usually inaccessible after being young, allowing patients to process difficult and fear-related memories.
Glue said the results were encouraging as they indicated a possible new way to treat PTSD.
However he stressed if it were to become available in New Zealand, the country lacked large numbers of clinical psychologists and/or psychotherapists to allow wide access to treatment.