Researchers Announce Completion of First Clinical Trial of Marijuana for PTSD in Veterans

PRESS RELEASE: Researchers Announce Completion of First Clinical Trial of Marijuana for PTSD in Veterans

Brad Burge, Director of Strategic Communications, MAPS
Media Requests:
Press Resources:

Today, researchers announced that the first randomized controlled trial of whole plant (botanical) marijuana as a treatment for posttraumatic stress disorder (PTSD) symptoms has been formally completed, with all 76 veterans having been enrolled and treated. The data from the study are now being analyzed and prepared for publication later this year in a peer-reviewed biomedical journal.

Sponsored by the non-profit Multidisciplinary Association for Psychedelic Studies (MAPS), the study is evaluating the safety and effectiveness of smoked marijuana to treat symptoms of PTSD in 76 U.S. veterans. Despite initial challenges with recruitment, the trial was nevertheless completed on time.

“We are thrilled to finally be at the finish line of this nearly 10-year saga trying to get this crucial clinical trial completed,” said Site Principal Investigator Sue Sisley, M.D. “We are immensely grateful to all of the study’s supporters, especially the veteran service organizations who helped us with patient recruitment. We are proud to have persevered through these regulatory hurdles independently of hospitals, universities, or the VA system.”

The results will provide physicians, patients, scientists, and regulators with critical knowledge regarding whether marijuana benefits individuals with PTSD, whether adverse consequences occur, and the impact of the chemical composition of marijuana, specifically ∆-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), on clinical outcomes.

The study has been funded by a $2.156 million grant to MAPS from the Colorado Department of Public Health and Environment, and conducted with approval and oversight from the U.S. Food and Drug Administration (FDA), Drug Enforcement Administration (DEA), and the National Institute on Drug Abuse (NIDA). Marcel Bonn-Miller, Ph.D., served as Coordinating Principal Investigator for the trial, and Paula Riggs, M.D., served as Co-Investigator.

About MAPS

Founded in 1986, MAPS is a 501(c)(3) non-profit research and educational organization that develops medical, legal, and cultural contexts for people to benefit from the careful uses of psychedelics and marijuana. Since its founding, MAPS has raised over $70 million for psychedelic therapy and medical marijuana research and education. For more information, visit

MAPS-sponsored clinical trials are conducted by the MAPS Public Benefit Corporation (MPBC), a wholly owned subsidiary of MAPS formed in 2014 for the special purpose of balancing social benefits with income from legal sales of MDMA, other psychedelics, and marijuana. For more information, visit