The use of cannabis for medicinal purposes is widespread in the US, yet little evidence is available on the effects of medical cannabis card acquisition. This study sought to evaluate the short-term effects of obtaining a medical cannabis card among adults seeking relief from chronic pain, insomnia, anxiety, or depression symptoms. In a single-site trial, participants randomized to wait 12 weeks before acquiring a medical cannabis card (n=81, 84% of those randomized) were compared with the subset of participants randomized to immediate card acquisition who successfully obtained a card (n=105, 61% of those randomized).
- Compared with the delayed card acquisition group, the immediate card acquisition group had more cannabis use disorder (CUD) symptoms (mean difference [MD], 0.28); fewer insomnia symptoms (MD, -2.90); and reported no significant changes in pain severity or symptoms of anxiety or depression.
- More participants in the immediate card acquisition group developed (mostly mild) CUD (17%), compared with those in the delayed card acquisition group (9%; adjusted odds ratio, 2.88), particularly among participants with a chief concern of anxiety or depressive symptoms.
- Multiple sensitivity analyses, including those attempting to control for the lack of an intention-to-treat analysis, documented similar results.
Comments: This study provides some of the best, if limited, evidence of the effects of medical cannabis card acquisition on a range of commonly targeted symptoms. While generally mild, the increased incidence of CUD among those acquiring cards—especially among those with anxiety or depression—is potentially concerning, while possible improvements in sleep begs further investigation. These findings are relevant to discussions with patients interested in using cannabis for its potential medicinal benefits.
Joseph Merrill, MD, MPH
Reference: Gilman JM, Schuster RM, Potter KW, et al. Effect of medical marijuana card ownership on pain, insomnia, and affective disorder symptoms in adults: a randomized clinical trial. JAMA Netw Open. 2022;5(3):e222106.