Examining the impact of the early stages of the COVID-19 pandemic period on youth cannabis use: adjusted annual changes between the pre-COVID and initial COVID-lockdown waves of the COMPASS study.

Background: Given the high rates of cannabis use among Canadian youth and that adolescence is a critical period for cannabis use trajectories, the purpose of this paper was to examine the effect of the early stages of the COVID-19 pandemic period on youth cannabis use in the context of a natural experiment. We used 3-year linked data from the COMPASS study, including 7653 Canadian (Quebec, Ontario) adolescents from which 1937 completed all 3 survey waves (pre-COVID-19 [2018, 2019] and online [2020] during the early pandemic period [May-July 2020]). Structural equation modeling (SEM) and double difference (DD) models were used to estimate pre-COVID-19 to initial COVID-19 pandemic period change (2019-2020) in cannabis use (monthly, weekly, daily) compared to 2018 to 2019 change to adjust for age-related effects.

Longitudinal associations between bullying and alcohol use and binge drinking among grade 9 and 10 students in the COMPASS study.

Objectives: Adolescents involved in bullying are at increased risk for alcohol use; however, much of this research has been cross-sectional. The aim of this work was to therefore examine the longitudinal associations between bullying and future alcohol use.

Methods: Data were drawn from the COMPASS study.