More Social Media Time Was Linked to Cannabis Experimentation in Early Teens

Daily social media time at Year 2 (around age 12) was significantly associated with cannabis experimentation at Year 4 (around age 14). Positive cannabis expectancies mediated 19.8% and negative expectancies mediated 13.6% of the social media-cannabis use association, even after adjusting for friends' cannabis use.

Longitudinal analysis of ABCD Study data (n=7,691, mean age 12 at Year 2), examining associations between daily social media time and cannabis use outcomes two years later, with mediation analysis testing whether cannabis expectancies at Year 3 explained the relationship.

With early adolescents spending increasing time on social media, understanding how digital media exposure shapes substance use attitudes and behaviors is critical for prevention. The mediation finding suggests that social media may influence cannabis initiation partly by shaping beliefs about its effects.

This study connects two major public health concerns: youth social media use and early substance initiation. The mediation through expectancies suggests that cannabis content on social media platforms may shape adolescent beliefs before direct experimentation occurs.

Observational design cannot prove social media causes cannabis use. Self-reported social media time may be inaccurate. Cannot identify what specific social media content drives the association (cannabis-specific content, peer influence, or general risk-taking culture). Residual confounding from unmeasured family and peer factors.