Modes of Marijuana Consumption Among Colorado High School Students

Introduction:  Colorado has been an early adopter with regard to liberal marijuana policy. The state passed a medical marijuana amendment in 2000, and – along with Washington – was the first to permit a legal market for recreational marijuana in 2012. One specific consequence of retail marijuana in Colorado may be an increase in the availability of alternative modes of marijuana consumption, such as vaporizers and edibles. The purpose of this presentation is to assess the prevalence of modes of marijuana consumption among Colorado youth, and explore variation by demographics, substance use, and risk perceptions.

Methods: Data are from a 2013 survey of Colorado high school students (n=25,197). The outcome variable was usual mode of marijuana consumption (i.e., smoking, vaporizing, ingesting edibles, or “other”), among youth who reported past 30-day marijuana use. Covariates included: sex, grade, race/ethnicity, sexual orientation, current use of alcohol and cigarettes, frequent marijuana use, early marijuana use (<14 years), perceived harmfulness, and perceived wrongfulness. We calculated prevalence estimates overall and by the variables listed above, and also ran multinomial logistic regression models.

Results: The most commonly reported usual mode of marijuana consumption was smoking (85.0%), followed distantly by vaporizing (6.2%), ingesting edibles (5.2%), or some other way (3.6%). Smoking marijuana was more commonly cited as the usual mode of use among girls vs. boys (89.2% vs. 81.7%) and among those reporting low vs. high perceived harmfulness (87.2% vs. 74.5%). The prevalence of smoking as the usual mode of marijuana consumption varied by race/ethnicity, with Asians having the lowest prevalence (74.8%) and Hispanics having the highest (90%).

Conclusions: A minority of Colorado youth who use marijuana usually use a mode of consumption other than smoking. Youth may be using vaporizers and ingesting edibles as a way to reduce the perceived harm associated with inhaling combusted smoke. Continued research on this topic will shed light on whether patterns of marijuana use among adolescents, who are by definition excluded from the legal marketplace, are impacted by retail marijuana.