Screen time, physical activity and mental health among urban adolescents in China.

OBJECTIVE: To test the association between screen time (ST), physical activity (PA) and self-reported psychological problems among urban adolescents aged 11 to 16 years.

METHODS: In 2010, total 5003 boys and girls were analyzed from 4 junior high schools in Bengbu city of China. The Depression Self-rating Scale for Children, Screen for Child Anxiety Related Emotional Disorders and School Life Satisfaction Rating Questionnaire were administered to obtain information on current mental health. Self-reported ST, PA and dietary intake were also assessed. Logistic regression analyses were used to explore the effects of ST and PA on psychological problems.

RESULTS: Approximately 26.1% of adolescents were exposed to ST for more than 2h/day. High ST was a risk factor for depressive symptoms (odds ratio (OR)=1.52, 95% confidence interval (CI): 1.31-1.76), anxiety symptoms (OR=1.36, 95%CI: 1.18-1.57) and school life dissatisfaction (OR=2.07, 95%CI: 1.79-2.38). Sufficient vigorous PA (VPA) was a protective factor for depressive symptoms (OR=0.78, 95%CI: 0.67-0.91) and school life dissatisfaction (OR=0.73, 95%CI: 0.62-0.85). The combination of high ST and insufficient VPA was associated with the highest prevalence of various psychological problems.

CONCLUSIONS: High ST and insufficient VPA interact to increase depressive, anxiety symptoms and school life dissatisfaction among Chinese adolescents.