Stress and Internalizing Problems in Adolescents: A Dynamic Longitudinal Analysis.

Background/Objectives: Internalizing problems commonly increase during adolescence, yet the precise nature of their reciprocal relationship with stress remains unclear. The present study aimed to clarify the directionality of this association by disentangling stable dispositional influences from dynamic, within-person processes. Specifically, we examined whether stress and internalizing symptoms exhibit bidirectional effects over time or are primarily shaped by enduring individual differences. Methods: A large, representative sample of 1618 secondary school students (671 males, 947 females; M = 16.3 years) completed measures of subjective stress, emotional problems, and peer problems across three time points spaced six months apart. Data were analyzed using the Random Intercept Cross-Lagged Panel Model (RI-CLPM), which separates stable between-person variance from within-person fluctuations. Model fit was assessed using established criteria (CFI, TLI, RMSEA). Results: Subjective stress and emotional problems were strongly associated, whereas the relationship between stress and peer problems was weaker. In both domains, associations were largely explained by stable, trait-like individual differences. All cross-lagged effects at the within-person level were non-significant, indicating no dynamic, time-ordered influence between constructs. These findings provide no empirical support for the stress sensitization or stress generation hypotheses but are consistent with diathesis-stress models emphasizing enduring dispositional vulnerability. Conclusions: The results suggest that the link between stress and internalizing symptoms during adolescence primarily reflects stable personality-based factors, such as neuroticism or emotional instability, rather than reciprocal causal processes. Preventive interventions should target emotional regulation and resilience to mitigate the impact of dispositional vulnerabilities on adolescent mental health.