The Long-Term, Prospective, Therapeutic Impact of Cannabis on Post-Traumatic Stress Disorder

Introduction: Given the increasing availability and use of cannabis among individuals with post-traumatic stress disorder (PTSD) and the addition of PTSD as an eligible diagnosis in several U.S. medical cannabis programs, the efficacy of dispensary-obtained cannabis needs to be thoroughly examined. Materials and Methods: This prospective study assessed PTSD symptoms and functioning every 3 months over the course of a year in two samples of participants diagnosed with PTSD: (1) those with PTSD using dispensary-obtained cannabis (cannabis users) and (2) those with PTSD, who do not use cannabis (controls). Linear mixed-effects models and generalized estimating equations tested whether trajectories of symptoms differed between the two subsamples. Results: A total of 150 participants (mean [standard deviation] age, 50.67 [15.26] years; 73% male) were enrolled in the study. Over the course of 1 year, the cannabis users reported a greater decrease in PTSD symptom severity over time compared to controls [groupxtime interaction=-0.32 (95% confidence interval [CI]=-0.59 to -0.05, R-2=0.13; t=-2.35, p=0.02). Participants who used cannabis were 2.57 times more likely to no longer meet DSM-5 criteria for PTSD at the end of the study observation period compared to participants who did not use cannabis (95% CI=1.12-6.07; p=0.03). Conclusions: This study provides evidence that the types of cannabis available in recreational and medical cannabis dispensaries might hold promise as an alternative treatment for PTSD. Randomized placebo-controlled trials are needed to assess safety and determine how different preparations of cannabis impact PTSD and functioning.

Automated summary

This study found that PTSD patients who used cannabis experienced a greater decrease in symptom severity and were more likely to no longer meet the diagnostic criteria for PTSD. It suggests that medical cannabis could serve as an alternative treatment for PTSD.