Association of Nighttime Sleep Duration with Depressive Symptoms and Its Interaction with Regular Physical Activity among Chinese Adolescent Girls

Depression has become a major mental health concern among adolescents globally, and the relationship between depressive symptoms and nighttime sleep duration among adolescent girls remains unclear. This study aimed to examine the association between nighttime sleep duration and depressive symptoms among Chinese adolescent girls. This cross-sectional study, conducted in 2018, included 4952 girls aged 10–19 years from the eastern, central, and western regions of China. Depressive symptoms were assessed by the Patient Health Questionnaire-9, and categorized into depressive symptoms and non-depressive symptoms. Logistic regression models were used to estimate the odds ratios (ORs) of depressive symptoms. After adjustment for covariates, adolescent girls with a nighttime sleep duration of