RESUMO
OBJECTIVE: Insufficient sleep and skipping breakfast are increasingly prevalent among children and adolescents. Both behaviors are associated with the onset of depression. This study aims to examine the independent and joint associations of these two behaviors with depressive symptoms, and investigate whether these associations varied by age or sex. METHODS: The Center for Epidemiological Studies Depression Scale (CES-D) was used to evaluate the depressive symptoms. This cross-sectional study including 11,887 students aged 11-19 years using a stratified cluster, multistage sampling method in Ningbo, China. Multiple logistic regressions were conducted to evaluate the independent and joint association between insufficient sleep, skipping breakfast and depressive symptoms. Sensitivity analyses and stratified analyses by age and sex were performed using the same modelling strategies. RESULTS: The overall prevalence of depressive symptoms was 15.27%. Skipping breakfast (Odds Ratio (OR) = 2.557, 95% Confidence Interval (CI) = 2.236-2.925) and insufficient sleep (OR = 1.547, 95%CI = 1.390-1.723) was independently associated with depressive symptoms. Compared to students with "sufficient sleep and breakfast every day", the OR was 4.385 (95%CI = 3.649-5.271) for those with "insufficient sleep and skipping breakfast". Meanwhile, the joint association was moderated by age group, with a more apparent association observed in the 11-15-year-old group compared to the 16-19-year-old group. CONCLUSIONS: These findings indicated that insufficient sleep and skipping breakfast were independently and jointly associated with depressive symptoms. Insufficient sleep and skipping breakfast could be considered as two of the predictors of depression.