Legal recreational cannabis tied to more claims of self-harm in younger men

(HealthDay)—Legalization of recreational cannabis appears to be associated with increases in rates of claims for self-harm among men younger than 40 years, according to a study published online March 18 in JAMA Network Open.

Ellicott C. Matthay, Ph.D., from the University of California, San Francisco, and colleagues used comprehensive claims data on 75,395,344 commercial and Medicare Advantage health plan beneficiaries (2003 through 2017) to evaluate the association of state medical and recreational cannabis laws with self-harm and assault. The analysis included overall changes and changes by age and sex based on within-state changes in claims for self-harm and assault injuries before and after changes in cannabis laws in all 50 U.S. states and the District of Columbia (29 states permitted use of medical cannabis and 11 permitted recreational cannabis).

The researchers found that point estimates for population-wide rates of self-harm and assault injuries were higher in states legalizing recreational cannabis versus states with no cannabis laws, although results were not statistically significant (assault: recreational dispensaries adjusted rate ratio [aRR], 1.27 [95 percent confidence interval (CI), 0.79 to 2.03]; self-harm: recreational dispensaries aRR, 1.15 [95 percent CI, 0.89 to 1.50]). There were differences observed by age and sex, but the only significant associations involved self-harm among men younger than 40 years in states with recreational policies (<21 years: recreational without dispensaries aRR, 1.70 [95 percent CI, 1.11 to 2.61]; 21 to 39 years: recreational dispensaries aRR, 1.46 [95 percent CI, 1.01 to 2.12]).

"States with recreational cannabis may benefit from monitoring levels of self-harm as a potential consequence of legalization," the authors write.