Predictors of Weekday and Weekend Screen Time in a Clinical Child and Adolescent Psychiatric Sample (Aged 12–18 Years)

Background/Objectives: Screen time in children and adolescents has become a prominent public health concern, yet most research has focused on community samples, leaving clinically referred youth underrepresented. This study examined predictors of weekday (WD-ST) and weekend screen time (WE-ST) in a clinical child and adolescent psychiatric sample, with a particular focus on problematic use of the internet (PUI), externalizing symptoms, and fear of missing out (FoMO). Methods: A retrospective secondary analysis of pooled datasets from multiple clinical studies was conducted with 173 adolescents (66.5% female; age range 12–18 years) receiving child and adolescent psychiatric treatment at the University Hospital of Salzburg, Austria. Multivariate linear regression analyses examined self-esteem, adaptive and maladaptive emotion regulation strategies, internalizing and externalizing symptoms, FoMO, and PUI as predictors of WD-ST and WE-ST separately. p-values were adjusted for multiple comparisons using the Benjamini–Hochberg False Discovery Rate correction. Results: In the follow-up hierarchical regression models, PUI was the strongest and most consistent predictor across both models, independently explaining 15.0% of variance in WD-ST time and remaining the only significant predictor in the final WE-ST. Externalizing symptoms significantly predicted WD-ST (β = 0.219, p = 0.021) but not WE-ST. FoMO showed a consistent positive association with WD-ST across both regression models, though this did not reach statistical significance. Self-esteem, emotion regulation strategies, and internalizing symptoms were not significantly associated with screen time in either model. Conclusions: Screen time in clinical adolescent populations cannot be adequately captured by duration alone. PUI reflects a compulsive quality of digital engagement independent of broader psychopathological burden, and the observed difference in weekday versus weekend predictors is consistent with a potential role of daily structure, though this was not formally tested in the present study. Routine clinical assessment should prioritize PUI-focused evaluation over aggregate screen time as a more sensitive indicator of clinically relevant digital engagement.