Cannabis Use, Screen Time, and Internalizing Symptoms among Canadian Youth: Testing Mediation Pathways

Background: Existing research suggests positive correlations between screen time sedentary behaviors (STSB) and substance use, including cannabis use, among youth. However, little research has examined what factors mediate these relationships.Methods: This study examined mediating pathways among STSB, internalizing symptoms (IS), and cannabis use in a linked longitudinal sample of 28 269 Canadian youth who participated in the COMPASS study over a two-year period (2017/18 to 2018/19). Structural equation modeling examined two main hypotheses cross-sectionally and over time: 1) if IS mediated associations between STSB and cannabis use frequency, and 2) if STSB mediated associations between IS and cannabis use frequency. Results: Results demonstrated significant partial mediation effects for both hypotheses. For example, indirect effects indicated that IS mediated the association between STSB and cannabis use both cross sectionally (95% CI: 0.021, 0.029) and longitudinally (95% CI: 0.006, 0.010). STSB also mediated associations between IS and cannabis use cross sectionally (95% CI: 0.015, 0.023) and longitudinally (95% CI: 0.010, 0.014). This study demonstrated that the associations between STSB, internalizing symptoms and cannabis use are complex, involving mediation in both directions.Discussion: These findings can be used to inform public health initiatives that aim to take a comprehensive approach to addressing negative health behaviors and outcomes, as it is clear that the multi-directional relationships between STSB and mental health may in-turn impact other health behaviors. Future research should continue to examine mediating factors between STSB and substance use among youth, including exploration of associations with other substances.Supplemental data for this article is available online at https://doi.org/10.1080/10826084.2021.1922455 .