Developmental Comorbidity of Substance Use and Handgun Carrying Among U.S. Youth

Abstract

This study identifies the longitudinal trajectories of multiple forms of substance use and handgun carrying and examines their comorbidity over time. In a cohort study of 6,748 youth from a U.S. nationally representative sample (51% male, 49% female; 69% White, 16% Black, 14% Hispanic, and 1% other race/ethnicity; born between 1980 and 1984), individuals self-reported their substance-use status (i.e., smoking, drinking, marijuana use, and hard drug use), handgun carrying, and other covariates between 1997 and 2013. Group-based trajectory modeling was used to identify distinct patterns of substance use and handgun carrying over time. Chi-square tests were used to determine the bivariate associations between substance-use and handgun-carrying trajectories, and a multinomial logistic regression examined the associations while adjusting for covariates. Analyses were conducted in 2020. Trajectories of all the 4 forms of substance use were associated with handgun-carrying trajectories. Specifically, the risk of being in the declining trajectory of handgun carrying (compared with that of being in the very-low trajectory) was higher for participants who were in the decreasing trajectories of smoking, drinking, marijuana use, and hard drug use and lower for those who were in the increasing trajectory of drinking. Inversely, the risks of being in the low and high-increasing trajectories of handgun carrying (compared with that of being in the very-low trajectory) were higher for participants who were in the increasing trajectory of hard drug use. Both substance use and gun carrying are developmentally heterogeneous phenomena. Varied forms of substance use should be targeted to counter the distinct gun carrying patterns.