Interrelationships among depression, anxiety, flourishing, and cannabis use in youth

The objective of the study was to examine if depression or anxiety was associated with youth cannabis use; and investigate whether flourishing, an indicator of overall wellbeing, moderates these associations.

Students (N=6550) were recruited from 10 secondary schools (grade 9-12) in Ontario and British Columbia, Canada. Self-report questionnaires were used to assess symptoms of depression [CESD-R-10], anxiety [GAD-7], flourishing [Deiner's Flourishing Scale], and cannabis use. Logistic regression and product-term interactions were used to examine the associations between mental health and youth cannabis use, and the potential moderating effect(s) of flourishing.

In our sample, 32% of participants had ever used cannabis, and 42% and 32% reported elevated depressive and anxiety symptoms, respectively. Associations between depression, anxiety, and cannabis use were no longer significant when flourishing was added to the models. In addition, there was no evidence suggesting a moderating effect of flourishing (all interactions were not statistically significant). Instead, robust associations were found between flourishing and cannabis use (ever use and frequency).

Indicators of mental wellbeing, such as flourishing, appear to be associated with a lower likelihood of cannabis use, even after controlling for depression and anxiety. Results suggest prevention strategies for youth cannabis use should aim to foster mental wellbeing among all youth, rather than exclusively targeting those experiencing mental health problems. Future longitudinal studies should test the sequential relationship between cannabis use and changes in both positive and negative mental health.