Study: Marijuana Legalization Not Linked to Rise in Adolescent Cannabis Use Disorder Hospitalizations

A study being published in the May issue of International Journal of Drug Policy and released online ahead of print today finds that state marijuana legalization was not associated with a statistically significant increase in adolescents being hospitalized for cannabis use disorder. The research was conducted by a team from Penn State College of Nursing in University Park, Pennsylvania. Researchers examined whether legalizing marijuana for adult use was linked to changes in hospital discharge data involving adolescents ages 10 to 17.

To do so, they analyzed more than 2.86 million inpatient discharge records from 13 U.S. states between 2008 and 2020, using a quasi-experimental model designed to compare outcomes across states with different legalization timelines. The focus was on discharge records that included a diagnosis of cannabis use disorder (CUD) in any position.

According to the findings, legalization was not tied to a statistically significant overall change in adolescent cannabis use disorder-related inpatient discharges. Researchers reported an average treatment effect equivalent to a 0.51 percentage point increase, but the confidence interval indicated the change was not statistically significant.

The study also found no significant changes during the first six years after legalization. Additional analyses based on dispensary opening dates and demographic subgroups, including sex, age, race, ethnicity and urbanicity, also found no statistically significant associations.

Researchers concluded by stating “Findings did not detect a statistically significant overall association between state nonmedical cannabis legalization and adolescent CUD-coded inpatient discharges. Estimates from the observed follow-up were consistent with no statistically detectable association, though potential delayed or cohort-specific effects cannot be ruled out.”