The Interplay Between Cannabis-Specific Risk Factors and Cannabis Use over the Course of Adolescence: Who, What, and When Matters?

Introduction: Over the past two decades, several states in the US modified their laws regarding adult use of medical and recreational cannabis. The associated public health concerns include possible increases in cannabis-specific risk factors (RFs) including permissive norms and attitudes about cannabis use, and the consequent increases in adolescent cannabis use. This study examines the relationship between cannabis-specific RFs and cannabis use over the course of adolescence. Understanding the interplay between RFs and cannabis use can guide development of preventive interventions to reduce unintended consequences of cannabis legalization for adolescents.

Methods and Results: We used the longitudinal panel data from The Community Youth Development Study, a randomized controlled trial of the Communities That Care (CTC) prevention system in 24 small and rural communities. Analyses used 6 waves of data from gender balanced, primarily non-Hispanic White sample of youth (n=2002) followed from grades 5-12 in the 12 control condition communities. The outcomes in this study were prevalence and frequency of past month cannabis use, and pro-cannabis use norms and attitudes of youth, as well as their perceived attitudes of their peers, parents and adults in their communities.  On a bivariate level, results indicate significant positive associations between cannabis-specific RFs and cannabis use at each grade. Markov models examined 1-year cross-lagged effects from grades 5 to 12 between cannabis-specific RFs and cannabis use. These models controlled for gender, age, ethnicity, parent education and rebelliousness at baseline and accounted for nesting in communities. Results point to reciprocal predictive associations between RFs and cannabis use. Youths who perceived their parents to hold permissive attitudes towards their children’s cannabis use and youths who reported that their close friends use marijuana were more likely to use cannabis in the subsequent year, adjusting for prior cannabis use.  These effects were particularly salient in mid-adolescence (Grades 8-10). Adolescent cannabis use also predicted perceptions of peers’, parents’ and community members’ attitudes about cannabis one year later, adjusting for prior levels of these variables.

Conclusions: This study expands the understanding of etiology of adolescent cannabis use, a key focus of prevention efforts in the context of cannabis legalization. Furthermore, it constitutes a building block for future examination of the potential CTC intervention effects on the relationship between RFs and cannabis use to understand the mechanisms through which community-based intervention can impact etiology of substance use. Implications for prevention and intervention programs and public policy will be discussed.