Income inequality modified adolescent substance use trajectories from 2018-19 to 2020-21: Findings from the COMPASS...

Little is known about the structural determinants of adolescent substance use during times of crises. This study examined whether income inequality modified trends in adolescent substance use during the COVID-19 pandemic.

Adolescent (12-19 years) data (n = 22007) from the Cannabis, Obesity, Mental health, Physical activity, Alcohol use, Smoking, and Sedentary behaviour (COMPASS) study were linked with census division (CD) data (n = 42) from the 2016 Canadian Census. Adolescents self-reported on their alcohol (including binge drinking), cigarettes, e-cigarettes, and cannabis use via questionnaire in 2018-19, and again in either 2019-20, or 2020-21. Income inequality was calculated at the CD-level of the school. Multilevel logistic regression models were used to examine whether income inequality modified trends in adolescent substance use through the inclusion of a cross-level interaction term (income inequality∗time).

The interaction term (income inequality∗time) was significant for monthly use of cigarettes, e-cigarettes, and alcohol, indicating heterogenous trajectories based on CD income inequality. Students attending schools in less equal areas had higher odds of monthly cannabis use at baseline (OR = 1.49, 95 % CI: 1.24, 1.80), but the interaction term was not significant indicating homogenous trajectories. Income inequality was not associated with monthly binge drinking at baseline and did not modify trajectories over time. Gender stratified models revealed similar results for males and females except for e-cigarette use.

Income inequality may have modified adolescent substance use trajectories during the COVID-19 pandemic, with both increased and decreased likelihoods observed. More research investigating potential mechanisms is needed.