Funding outcome

More than 1 million, or every fourth, young people live with mental disorders in Canada, and three-quarters of all mental disorders emerge before age 25. A healthy lifestyle is a proven determinant of youth's physical health, but emerging studies suggest that those who meet lifestyle recommendations for diet, physical activity, sedentary behaviour, and sleep are also doing better in terms of their mental health. These studies, however, have several limitations: most focused on a single lifestyle factor, such as sleep. No study accounted for substance use (tobacco smoking, vaping, cannabis use, binge drinking) that are known to negatively affect mental health. Also, most studies were conducted at one point in time whereas it is better to follow people over time. Adolescence is a critical time for the development of healthy lifestyle behaviours, but we know little about how much the lifestyle behaviours may contribute to the mental health burden. We propose to study whether adolescents are meeting established recommendations for diet, physical activity, sedentary behaviour, sleep as well as substance use (tobacco smoking, vaping, cannabis use, binge drinking) and examine their link with common mental disorders (depression and anxiety). We will examine this for girls and boys separately. We will use available longitudinal data on 28,577 grade 9-12 youth that are followed prospectively and that were recruited from 120+ secondary schools in AB, BC, ON, QC and Nunavut. Results will generate important knowledge to help reduce the mental health burden by informing primary prevention efforts that consider lifestyle approaches for promoting mental health throughout adolescence.