Is problematic internet use always problematic? An experience-sampling study of compulsive and avoidance-driven internet behaviors and momentary mood

OBJECTIVE: The internet has transformed communication and entertainment. Population-level studies typically find that higher problematic internet use (PIU) is associated with lower well-being. We explored how well that average describes individuals using an idionomic (within-person-first) design. METHOD: Over 10 days, 84 young adults (Mage = 23.5) completed five daily surveys assessing four Young's (1998) PIU-related behaviors (two time control/compulsivity; two emotion dysregulation/avoidance) and six bipolar mood states. We estimated within-person associations using idiographic autoregressive integrated moving average with exogenous inputs, summarized heterogeneity with random-effects and Bayesian multilevel meta-analysis, and explored subgroups via partitioning around medoids and growing self-organizing Maps. RESULTS: At the within-person level, being above one's own PIU baseline generally linked to lower immediate mood, though effects varied: For some, higher-than-usual PIU coincided with better mood, for others, with worse mood. At the between-person level, individuals with habitually higher PIU reported lower average mood. CONCLUSIONS: Findings support measurement-based tailoring: If higher-than-usual PIU lifts mood now but carries later costs, practitioners might emphasize delay-of-gratification strategies; if it dampens mood immediately, they may use awareness/functional mapping approaches. Future studies should test whether person-specific measures improve intervention choice. (PsycInfo Database Record (c) 2026 APA, all rights reserved).