Problematic media use, but not device time, tracks mental health issues: A four-wave cohort study in adolescents

Background. Adolescent screen use has been linked to mental health issues, yet there remains confusion as to the respective role of time spent on media versus that of self-reported problematic use of media. Moreover, this work mainly focuses on average differences across adolescents, but rarely asks whether deviation in personal use actually impacts mental health down the line. Methods. We followed 550 German-speaking Swiss adolescents (median age 13 years, 295 girls) across four waves six months apart. At each wave they reported time spent on five device categories (mobile phone, computer, tablet, video game console, and television), problematic use on three different media (mobile phone - PMPU, social media - PSMU and video games — PVGU), as well as mental health issues spanning anxiety, depression, well-being and ADHD symptoms. For every variable pair, we fitted a cross-lagged panel model (CLPM) and a random-intercept version (RI-CLPM), adjusting for age, gender and socioeconomic status. Paths were interpreted when the mean standardized coefficient reached the medium benchmark (|β| ≥ .07). Results. Cross-lagged panel models describe trends between adolescents. Here, as expected from the literature, on average smartphone time and PMPU predicted each other, as did console time and PVGU. Of note, problematic use, especially PSMU, showed strong reciprocal ties with mental health issues, whereas screen time was only weakly associated with mental health when considering mobile phones. Within adolescents, RI-CLPM models showed the same pattern, with mental health issues being only related to problematic use, especially PSMU, but none of the media time. Rising depressive symptoms and falling well-being each preceded higher PVGU without a reverse path. Interestingly, anxiety showed no within-person coupling. Conclusions. Time spent on devices indicated which adolescents reported problematic use but not whether a given adolescent’s mental health deteriorated. Problematic use in contrast closely tracked mental health issues, particularly for depressive and ADHD symptoms. Screening that counts hours is at risk of missing mental health issues; rather, signs of impaired control over social media use, as well as mobile phone use are a more robust target.