FDA Approves Landmark Study on Smoked Marijuana for Treating PTSD in Veterans

The U.S. Food and Drug Administration (FDA) Division of Psychiatry Products has cleared the Multidisciplinary Association for Psychedelic Studies (MAPS)’ Phase 2 study of smoked cannabis in Veterans for the treatment of PTSD (MJP2) to proceed. Initially placed on partial clinical hold by the FDA in 2021, MJP2 is a randomized, placebo-controlled study of 320 Veterans suffering from moderate to severe PTSD who have previously used cannabis.

Funded by the Michigan Veteran Marijuana Research Grant Program, trial will investigate the effects of inhaling high-THC dried cannabis flower versus a placebo, allowing participants to self-titrate their dosage. MAPS noted the study reflects real-world consumption patterns, aiming to assess both the benefits and risks of cannabis use for PTSD treatment.

The project faced significant regulatory delays, with MAPS navigating three years of negotiations and responding to five partial clinical hold letters from the FDA. On August 23, 2024, MAPS resolved these issues through a Formal Dispute Resolution Request, addressing concerns around THC dosing, delivery methods (smoking and vaping), and the inclusion of cannabis-naïve participants.

Sue Sisley, a psychologist and the trial’s principal investigator, emphasized the importance of the research. “Millions of Americans are smoking or vaporizing cannabis to manage or treat their symptoms,” Sisley said. “In the absence of high-quality data, much of the information available to patients and regulators is rooted in prohibition and focused only on potential risks, without consideration of potential benefits.”

Allison Coker, MAPS’ director of cannabis research, explained that the FDA approved smoked cannabis with commercially available THC levels, though vaporization remains on hold pending safety evaluations of delivery devices. The study protocol now requires participants to have prior experience inhaling cannabis to address FDA concerns about potential risks associated with self-titrated dosing.

“MAPS takes pride in leading the way to open new research pathways by challenging the FDA to think differently,” Coker said. “Our cannabis work challenges FDA’s typical approach to scheduled dosing and administration of drugs.”

The FDA acknowledged the need for additional PTSD treatment options but did not elaborate on what led to the approval of Phase 2.

Funding for the trial comes from Michigan’s Veteran Marijuana Research Grant Program, which uses state cannabis tax revenue to support studies on marijuana’s efficacy in treating veterans’ medical conditions and reducing suicide rates. In 2021, Michigan allocated $13 million to MAPS’ study as part of a $20 million funding round. The remaining $7 million was granted to Wayne State University to explore cannabis treatments for PTSD, anxiety, depression, and related conditions.

This research marks a significant step in understanding the therapeutic potential of cannabis, with implications for millions of veterans and others living with PTSD.