Study: Long-Term Cannabis Use May Reduce PTSD Symptoms

A Colorado Department of Public Health and Environment-funded study found over the course of one year, post-traumatic stress disorder sufferers who used cannabis reported a greater decrease in symptom severity than a control group and were 2.57 times more likely to no longer meet the DSM-5 criteria for the condition.

The study, published ahead of print in the journal Cannabis and Cannabinoid Research, concluded that cannabis “might hold promise as an alternative treatment for PTSD” but that “randomized placebo-controlled trials are needed to assess safety and determine how different preparations of cannabis impact PTSD and functioning.”

For the study, researchers followed two groups of PTSD patients throughout the year-long period and one group used legal medical cannabis, while the other group did not use cannabis at all, according to a Forbes report outlining the study. The 150 participants – with an average age of 50.67 and 73% male – met the DSM criteria for PTSD. At the beginning of the study, participants were assessed for the condition and their symptom severity, and again every three months thereafter. Cannabis use was confirmed by urine tests. Most of the 75 cannabis users used flower high in THC content, the report says.

The study – conducted by researchers at the University of Pennsylvania, University of California, San Diego, Johns Hopkins School of Medicine, and University of Colorado – adds to the growing body of scientific literature to support cannabis’ role as a therapeutic for PTSD and its inclusion as a qualifying condition in medical cannabis programs throughout the U.S.

A study published in June by Washington State University researchers included data from more than 400 PTSD patients and found cannabis reduced the immediate symptoms of PTSD, including irritability by 67 percent, returning thoughts of a traumatic event by about 62 percent, anxiety by 57 percent, and flashbacks by 51 percent.

A study published in November 2019 using research from the 2012 Canadian Community Health Survey on Mental Health concluded that “cannabis use may contribute to reducing the association between post-traumatic stress disorder and severe depressive and suicidal states.”

A Minnesota Department of Health study from 2019 found more than 70 percent of medical cannabis patients enrolled in the state program for PTSD reported a reduction in their symptoms.

In all, 23 states include PTSD as a qualifying condition for medical cannabis access.