Abstract
INTRODUCTION: Sleep and mental health are closely linked. In Aotearoa New Zealand, poor mental health is more prevalent for Māori and Pacific adolescents, who are disproportionately impacted by social and sleep inequities, raising the question of whether sleep contributes to adolescent mental health inequities. We aimed to (1) examine associations between sleep and mental health and (2) explore the contribution of sleep to associations between ethnicity and mental health, by conducting secondary analyses of cross-sectional Youth19 Survey data. METHODS: Multivariable logistic regression models were concurrently and sequentially adjusted for social determinants of health (e.g., housing deprivation), covariates (e.g., school year) and sleep (sleep duration; bedtime; waketime) to investigate independent associations between sleep and mental health (anxiety symptoms; depressive symptoms; attempted suicide) and the contribution of sleep to mental health inequities respectively. RESULTS: The sample comprised 7,721 12-18 year-olds. Independent associations (OR [95% CI]) were found between short sleep and anxiety (1.24 [1.06-1.46]) and depressive (1.75 [1.31-2.32]) symptoms; bedtime after midnight and attempted suicide (1.93 [1.13-3.30]); and waketime before 6am and attempted suicide (1.71 [1.12-2.62]). Māori and Pacific adolescents had increased odds of all mental health measures. Adjusting for social determinants and covariates fully attenuated these relationships for anxiety and depressive symptoms and partially for attempted suicide. Further adjustment for sleep reduced point estimates, although the inequity in attempted suicide remained for Pacific adolescents. DISCUSSION: Sleep may be a pathway linking social disadvantage to poor adolescent mental health. Sleep and social inequities must be addressed to support equitable adolescent mental health.