Abstract
Based on Chinese Students' Fitness Health Examination, this study sought to investigate the relationships between depressive symptoms and family environment, physical activity, dietary habits, sleep and sedentary behavior among children and adolescents. A cross-sectional study was carried out to estimate the prevalence of depressive symptoms in 32,389 participants (grades 4-12) using the CES-D. Logistic regression was used to evaluate the relationships between lifestyle determinants and depressive symptoms, and a random forest model was used to rank the importance of those determinants. The overall prevalence of depressive symptoms was 39.93%. Students with depressive symptoms had higher grades, lower parental educational levels and unhealthy lifestyles (P < 0.05). The top ten most important determinants of depressive symptoms were grade, egg intake, milk/soy product intake, frequency of muscle strength training, screen time, sleep duration, parental educational level, sugar beverage intake and total physical activity. Socioeconomic status, physical activity, sleep and screen time, and diet habits are determinants of depressive symptoms, and surveillance of lifestyles may be an effective way to detect students with depressive symptoms early.