Relationships between sleep and internalizing problems in early adolescence: Results from Canadian National Longitudinal Survey of Children and Youth.

BACKGROUND: Both inadequate sleep and internalizing problems, such as symptoms of anxiety and depression, are prevalent among adolescents with sparse epidemiological literature outlining sex-specific relationships at this critical age. OBJECTIVE: To examine cross-sectional and prospective relationships between self-reported sleep problems, indicated by sleep duration, difficulties getting to sleep and changes in difficulties getting to sleep with internalizing problems in early adolescence. METHODS: This study was a secondary analysis of data from the Canadian National Longitudinal Survey of Children and Youth. Multivariable linear regression was used to estimate cross-sectional and longitudinal associations. Relevant family and social context variables were controlled for in multivariable analyses. Family functioning was assessed as a potential effect modifier. RESULTS: There were 993 and 736 participants [longitudinal cohort entry age of 10 or 11 years; 49% male] in longitudinal and cross-sectional analyses, respectively. Most cross-sectional multivariable analyses of sleep duration and internalizing problems revealed no statistical associations. Difficulties sleeping and concurrent internalizing problems were positively associated in 12/13 year old females (beta = 1.77 [0.94, 2.61], R(2) = 17%) and males (beta = 1.18 [0.36, 2.01], R(2) = 16%). High persistent difficulties sleeping in females aged 12/13 to 14/15 years also positively predicted internalizing problems in females age 14/15 years (beta = 1.90 [0.52, 3.29], R(2) = 21%) while controlling for initial internalizing symptoms. Family functioning was not found to be an effect modifier. CONCLUSION: Findings highlight the potential role of difficulties sleeping for adolescents' mental health. Public health initiatives to promote sleep hygiene in this population subgroup are critical to prevent the potential long-term health impact of sleep problems.