Subjective norms as a mediator between exposure to online alcohol and marijuana content and offline use among adolescents

Introduction: While adolescent substance use (SU) may be viewed as normative, SU can quickly escalate leading to consequences. Social media use may increase SU risk. Despite using social media to connect with others, adolescents also view depictions of glamorised SU by both peers and influential figures. Exposure to online alcohol and marijuana content may impact subjective norms (i.e., injunctive and descriptive) ultimately leading to increased offline SU. Data from a multi-wave project was collected to assess whether subjective norms-mediated associations between exposure to alcohol and marijuana content by peers and influential figures on Instagram and Snapchat and offline SU.Methods: At Wave 1, participants were 264 adolescents (M-age = 14.91, 51% female, 86% White, 85% Hispanic/Latino/a/x).Results: Injunctive norms significantly mediated associations between exposure to alcohol content posted by peers and influential figures on Instagram and Snapchat and offline alcohol use. Injunctive norms significantly mediated associations between exposure to marijuana content posted by peers and influential figures on Instagram, and peers on Snapchat and offline marijuana use. Descriptive norms significantly mediated associations between exposure to alcohol content posted by peers on Instagram, as well as peers and influential figures on Snapchat and offline alcohol use.Discussion and Conclusion: Increased exposure to online SU content was more consistently associated with injunctive norms rather than descriptive norms. Future research should examine which social media features (e.g., the like button) contribute to increased subjective norms. Overall, findings suggest that social media may strongly convey approval of SU behaviours rather than actual use.