Cross-sectional and longitudinal associations of screen time with adolescent depression and anxiety

The relationship between screen time and mental health in adolescents is debated in the scientific literature, with longitudinal studies lacking. This study examined the cross-sectional and longitudinal associations between screen time and depression and anxiety and the influence of maladaptive social media use and gender on these associations.

We analysed a sample of 4058 adolescents (mean age = 13.9) recruited from 134 Australian schools as part of the Future Proofing Study, a 5-year prospective cohort study of adolescent mental health. Linear mixed models used Time 1 and Time 2 (12-month follow-up) data to examine cross-sectional and longitudinal associations of screen time with depression and anxiety and the influence of maladaptive social media use and gender.

Screen time was associated with mental health symptoms cross-sectionally, with each additional hour of screen time corresponding with a 1.25 and .79 increase in measures of depression and anxiety, respectively. Longitudinally, these associations were markedly weaker. Each additional hour of screen time corresponded with only a .15 increase in depression at 12 months and showed no association with anxiety at 12 months. Neither gender nor maladaptive social media use substantially influenced screen time-symptom associations.

Compared to cross-sectional associations, longitudinal associations were weak, indicating that high screen time is unlikely to cause depression and anxiety; instead, observed relationships may be bidirectional. Experimental studies to understand the nuances underlying the relationship between screen time and mental health are needed to support the development of targeted strategies that promote healthy screen time habits among adolescents.