Digital technology use, physical activity, and internalizing symptoms in adolescence: replication and extension in a post-pandemic cohort

Adolescent social media use is increasing, raising concerns about its impact on mental health. This study aimed to (1) examine differences in adolescent digital technology interactions pre- and post-COVID−19, (2) assess associations between technology use and internalizing symptoms (depression and anxiety) by gender and age, and (3)evaluate physical activity as a potential mediator of these associations. We analyzed two cross-sectional, quota-sampled U.S. adolescent cohorts (2019: N = 4,592; 2021: N = 2,487) using the Adolescent Digital Technology Interactions (ADTI) and measures of anxiety, depression, and physical activity. Bivariate associations, regressions, and mediation analyses were conducted. Technology use increased significantly from 2019 to 2021 across all gender and age groups (p < .001), although effect sizes were small. Higher digital technology use was associated with increased symptoms of depression and anxiety, with the strength of association varying by gender. Male adolescents showed stronger associations between technology use and internalizing symptoms. Findings highlight the importance of individualized approaches to understanding adolescent mental health.