Medical marijuana card ownership linked to cannabis use disorder

Immediate acquisition of a medical marijuana card led to an increase of cannabis use disorder and improved sleep, but saw no significant improvement in pain, anxiety or depressive symptoms, experts reported in JAMA Network Open.

“Given the increasing prevalence of cannabis use for medical concerns, well-designed studies are needed to assess the effect of cannabis product use on target symptoms and associated adverse medical and psychiatric events,” Jodi M. Gilman, PhD, department of psychiatry at Massachusetts General Hospital, and colleagues wrote.

Researchers sought to evaluate the outcomes on adults who obtained a medical marijuana card for cannabis use disorder (CUD) symptoms, while also considering symptoms of chronic pain, insomnia, anxiety or depression.

The study was conducted as a single-site, single-blind randomized clinical trial in the Greater Boston area, featuring 186 adults aged 18 to 65 years, from July 1, 2017, to July 31, 2020. Researchers placed participants in either an immediate card acquisition group (n=105) or a delayed card acquisition group (n=81) on a 2:1 basis organized by chief symptomatic concern, age and sex. Statistical analysis followed an evaluable population approach.

Those from the immediate acquisition group could acquire their card following randomization, while the delayed group had to wait 12 weeks. All trial participants could choose cannabis products from a dispensary, their dose and how frequently they used cannabis, while also being permitted to continue any medical or psychiatric care.

Results showed that the immediate card acquisition group demonstrated more CUD symptoms (MD, 0.28; 95% CI, 0.15-0.40; P < .001) and fewer issues with insomnia (MD, –2.9; 95% CI, –4.31 to –1.51; P < .001), while also reporting no significant changes in severity of pain or anxiety or depressive symptoms compared with the delayed card group.

“Although the development of CUD may suggest the likelihood of future medical marijuana card ownership, participants in this study did not have evidence of problematic cannabis use at baseline, and yet some participants developed CUD over the first 12 weeks of card ownership,” Gilman and colleagues wrote.