E-Cigarette and Cigarette Use Among US Adolescents: Longitudinal Associations With Marijuana Use and Perceptions

Introduction: Researchers have shown a connection between e-cigarette use and subsequent cigarette use. This study prospectively examines the connection between e-cigarette use and marijuana use. Methods: This study used data from the Monitoring the Future panel study of 12th graders in 2014 who were followed up 1 year later (n=305). Past-30-day marijuana use and perceived riskiness of marijuana use for 12th graders who used neither e-cigarettes nor cigarettes (78.6%), only e-cigarettes (10.3%), and cigarettes (with or without e-cigarettes; 11.1%) were compared. Data was analyzed in 2019. Results: At baseline, 40.1% of e-cigarette only users, 48.8% of cigarette users, and 13.2% of nonusers reported past-30-day marijuana use at baseline. E-cigarette only users were less likely to perceive any marijuana as risky at follow-up than nonusers (AOR=0.15, 95% CI=0.04, 0.65). Similarly, e-cigarette only users were more likely to report past-30-day marijuana use at follow-up than nonusers (AOR=3.82, 95% CI=1.45, 10.04), as were those who used cigarettes (AOR=7.63, 95% CI=2.65, 21.97). Conclusions: E-cigarette use, even when not in conjunction with cigarette use, may be a marker of marijuana use risk during the transition from adolescence to young adulthood. The e-cigarette and marijuana use link may strengthen in the future with the increasing trend of adolescents vaping marijuana. (C) 2020 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.