A budding problem: Marijuana use in pediatric trauma patients before and after legalization.

Abstract

Marijuana legalization may influence adolescent substance use patterns and injury mechanisms, but pediatric data remain limited. Michigan's 2018 legalization of recreational marijuana created a natural setting to evaluate these trends. This study examined changes in marijuana detection and associated clinical outcomes among adolescent trauma patients before and after legalization. We conducted a retrospective cohort study of patients aged 12 to 18 years treated at a Level I pediatric trauma center from 2015 to 2024. Demographics, injury characteristics, toxicology results, and outcomes were compared between prelegalization and postlegalization eras. Urine drug screening and blood alcohol concentration results were reviewed. Multivariable logistic regression identified independent predictors of tetrahydrocannabinol (THC) positivity. Among 2,386 adolescents (1,123 prelegalization; 1,263 postlegalization), THC positivity increased from 19.5% to 34.4% among screened patients (p < 0.001) and from 4.6% to 8.7% across all trauma patients (p < 0.001). Violent mechanisms rose from 27.0% to 36.0% (p < 0.001). Independent predictors of THC positivity included postlegalization era [adjusted odds ratio (aOR) 2.39, 95% CI: 1.47-3.91], violent mechanism (aOR: 2.38, 95% CI: 1.45-3.91), older age (aOR: 1.21 per year, p = 0.002), and alcohol co-positivity (aOR: 10.19, 95% CI: 2.70-39.57). THC-positive adolescents were more often discharged to justice or psychiatric facilities (7.0% vs. 3.2%, p = 0.04), while length of stay, operative intervention, and mortality were similar. Following recreational marijuana legalization, THC detection among adolescent trauma patients increased alongside a higher proportion of violent injuries. Physiologic outcomes remained unchanged, but psychosocial sequelae were more common. Implementing standardized toxicology screening and early substance use counseling within pediatric trauma systems may enhance identification and prevention. (J Trauma Acute Care Surg. 2026;00: 00-00. Copyright © 2026 Wolters Kluwer Health, Inc. All rights reserved.). Prognostic/Epidemiologic; Level III. Retrospective cohort study.