A prospective study of screen time in adolescence and depression symptoms in young adulthood

Objectives: The purpose of this study was to examine the association between screen time in adolescence and depressive symptoms in young adulthood in a population-based cohort study of Danish adolescents.

Methods: Data were from a cohort of adolescents who were followed-up in young adulthood for a period of up to 12 years (1997-2010, mean 8.8 years, n=435). Information on television viewing, computer use, total screen time and other determinants of depression were obtained in adolescence. Depressive symptoms were obtained in young adulthood using the Major Depression Inventory (MDI) and classified as mild, moderate or severe depression. Mixed regression models were used to examine the associations, with adjustment for major confounders.

Results: In multivariable adjusted analyses, each additional hour/day spent watching television or screen viewing in adolescence was associated with 1.36 (95% CI 0.73-1.98) and 1.05 (95% CI 0.50-1.60), respectively, greater MDI depression summary score in young adulthood (p<0.001). In logistic regression models, each additional hour/day spent watching television or screen viewing was associated with 1.64 (95% CI 1.18-2.27) and 1.58 (95% CI 1.18-2.12), respectively, greater odds of prevalent depression in young adulthood, and dose-response relationships were indicated. Additional adjustment for either cardiorespiratory fitness or BMI did not materially change the results. No significant associations were observed between adolescent computer use and depressive symptoms in young adulthood.

Conclusions: Limiting screen time, particularly television viewing, during adolescence may be important for preventing depression in young adulthood.