After three years and lots of back-and-forth, the FDA finally greenlit the Multidisciplinary Association for Psychedelic Studies’ (MAPS) Phase 2 study of smoked cannabis in veterans for the treatment of PTSD (MJP2). This study will test the safety and efficacy of inhaled cannabis (high THC) versus a placebo to manage PTSD symptoms and pain in about 320 veterans across Michigan and three other states. The study is backed by a $12.9 million grant from the Michigan Veteran Marijuana Research Grant Program, funded by state cannabis tax revenue.

Many doctors recognize marijuana's potential to treat physical conditions like chronic pain or epilepsy but are hesitant to consider it for psychological conditions. In August 2019, the American Psychiatric Association (APA) released two statements, “Position Statement In Opposition to Cannabis as Medicine” and “Position Statement Against the Use of Cannabis for PTSD,” opposing the use of cannabis to treat any psychiatric disorder, and specifically PTSD, citing a lack of credible studies showing its effectiveness. They concluded that no high-quality evidence supports using cannabis to treat PTSD and called for more research.

MJP2 aims to address that lack of research, and the initial study protocol challenged several of the conventional limitations placed on marijuana research: 1) the proposed THC dose, 2) smoking as a delivery method, 3) vaping as a delivery method, and 4) including participants who have never used cannabis. MJP2 is designed to reflect real-world marijuana use among veterans by using the most common delivery methods in the US, smoking and vaping, and using high-THC cannabis similar to what's available in states with legal cannabis. Participants can self-titrate, meaning they can adjust their dose up to a daily limit.

However, several of these protocols met FDA pushback. While the FDA approved high-THC self-titration and smoking, it gave only preliminary approval for vaping, pending more information on the specific vaporization device(s) that will be used. The FDA also did not allow marijuana-naïve participants, so MAPS updated the protocol to require that all participants have prior experience inhaling cannabis.

MAPS’s success in navigating research hurdles and the FDA’s willingness to compromise may signal that US regulatory agencies are starting to catch up with the public’s changing attitudes toward marijuana. On May 21, 2024, the DEA proposed moving marijuana from Schedule I to Schedule III of the CSA, aligning with the Department of Health and Human Services' view that marijuana has accepted medical use and a lower potential for abuse and dependence. On December 2, 2024, the DEA held a preliminary hearing that addressed legal and logistical issues and set future dates for an evidentiary hearing. If this change happens, it could significantly impact marijuana research and potentially open doors for studying other restricted substances like MDMA and LSD.

This article was authored by Laura Kiser, Research Analyst.