Longitudinal trajectories and psychosocial predictors of problematic smartphone use in Polish adolescents

Problematic smartphone use (PSU) is an increasing concern for adolescent mental health. This three-wave longitudinal study examined PSU trajectories and psychosocial predictors in 416 Polish adolescents (ages 11–18) across one academic year. Latent class growth analysis compared one- to four-class models; a three-class solution provided the best fit: High-Stable (persistently elevated Smartphone Application-Based Addiction Scale [SABAS] scores; n = 97), Mid-Stable (moderate, stable; n = 235), and Low-Decreasing (elevated baseline with decline; n = 84). Across waves, 20–22% met the SABAS cutoff, with higher prevalence among girls. Between-class comparisons showed clear psychosocial differentiation: the Low-Decreasing group reported the poorest adjustment (greater emotion regulation difficulties, higher anxiety, lower well-being), whereas the High-Stable group showed the most adaptive profile. In multinomial logistic regression, emotion regulation difficulties uniquely predicted higher odds of belonging to Mid-Stable (RRR = 1.07, 95% CI [1.04, 1.10]) and Low-Decreasing (RRR = 1.10, 95% CI [1.06, 1.13]) relative to High-Stable, while other predictors were nonsignificant. Sensitivity analyses with posterior-probability weighting yielded the same inferences. Findings indicate heterogeneous PSU courses in adolescence and highlight emotion regulation as a key differentiator of risk profiles. Results support integrating emotion-focused strategies into prevention and demonstrate the value of person-centered, longitudinal designs.