Longitudinal Relationships between Academic Stress, Depressive Symptoms, and Problematic Internet Use in Early and Late Adolescence.

Although academic stress, depressive symptoms, and problematic internet use are prevalent during adolescence, how these experiences dynamically interact and develop over time—particularly across early and late adolescence—remains insufficiently understood. This study addresses this gap by examining the reciprocal relationships and developmental trajectories of these constructs using Random Intercept Cross-Lagged Panel Models (RI-CLPM) and Latent Growth Models (LGM), focusing on differences between early and late adolescence. The study surveyed 1,531 early adolescents (Mage = 12.30, SDage = 0.55, 50.95% girls) and 1,620 late adolescents (Mage = 15.18, SDage = 0.51, 50.43% girls) over one year, with three waves of data collection. The RI-CLPM results showed that academic stress, depressive symptoms, and problematic internet use were positively correlated at the between-person level in both developmental stages. At the within-person level, early adolescents exhibited only autoregressive stability, whereas late adolescents showed that fluctuations in depressive symptoms predicted increases in academic stress, which in turn led to higher depressive symptoms and problematic internet use. The LGM results indicated that early adolescents exhibited parallel increases across all three constructs, while late adolescents showed divergent patterns: academic stress increased, depressive symptoms remained stable, and problematic internet use decreased. These findings indicate that the reciprocal relationships and developmental trajectories among academic stress, depressive symptoms, and problematic internet use differ between early and late adolescence, with early adolescence emerging as a critical period for enhancing emotion regulation and environmental support to prevent the development of maladaptive feedback cycles in later stages.