Moving beyond perceived riskiness: Marijuana-related beliefs and marijuana use in adolescents.

Background: Perceived riskiness of marijuana in adolescents has been trending downward in the context of increasing legality and availability. Low perceived riskiness has been associated with marijuana use though evidence is lacking on associations among use and more specific claims about marijuana's safety and benefit, improved understanding of which could guide clinical interventions to reduce use. Methods: We analyzed cross-sectional survey data collected from 502 adolescents aged 14-18 years recruited from an urban adolescent primary care clinic. Self-report questionnaires were administered via tablet computer. Use of marijuana was assessed with a brief validated screening tool, and agreement with each of five statements about marijuana's riskiness and health properties were reported using a four-point Likert scale. We conducted multivariable logistic regressions to determine the association between perceived riskiness and other marijuana-related beliefs and past-year marijuana use. Results: In total, 149 adolescents reported past-year marijuana use (29.7%). High overall perceived risk was associated with lower rates of past-year use (AOR 0.27, 95%CI: 0.15-0.48). Agreement with positive health beliefs that "marijuana can help teenagers focus in school" and that "marijuana is safe because it's natural" were associated with past-year marijuana use (respectively, AOR 5.50, 95%CI: 3.06-9.88 and AOR 6.61, 95%CI: 3.59-12.19) while agreement with negative health beliefs that "marijuana can affect youth even after they don't feel high anymore" and that "marijuana can be addictive" were both associated with lower rates of use (AOR 0.56, 95%CI: 0.31-0.99, and AOR 0.30, 95%CI: 0.16-0.56, respectively), adjusting for sociodemographic factors and use of other substances. Conclusions: Marijuana use varied in association with beliefs about its beneficial and harmful health properties. Clinical interventions that target specific marijuana-related health beliefs including unfounded claims of benefit may provide robust talking points for centering provider guidance and public health messaging.