Trajectories of intolerance of uncertainty in adolescents: Associations with anxiety and depression.

Intolerance of uncertainty (IU), a psychological vulnerability reflecting difficulty tolerating uncertain situations, is particularly salient during adolescence, a period marked by rapid neurocognitive development, increasing social and academic demands, and heightened exposure to uncertainty. IU has recently been regarded as a transdiagnostic risk factor for anxiety and depression, yet most existing studies rely on cross-sectional, variable-centered designs. This study aimed to identify distinct developmental trajectories of IU and examine their associations with anxiety and depression using a longitudinal, person-centered approach. A total of 2076 adolescents (mean age = 14.20 years, SD = 1.95; 57.6% girls) participated in a three-wave study, completing self-report measures of IU, anxiety, and depression. Latent class growth analysis identified three IU trajectories: stable (59.7%), decreasing (30.3%), and increasing (10.0%). Logistic regression analyses, adjusting for sociodemographic factors, baseline IU, and baseline anxiety and depressive symptom severity, showed that adolescents with increasing IU had significantly higher odds of anxiety (OR = 3.75, 95% CI = 2.47-5.67) and depression (OR = 3.10, 95% CI = 2.11-4.55), while those in the decreasing group had lower odds of anxiety (OR = 0.30, 95% CI = 0.16-0.57) and depression (OR = 0.31, 95% CI = 0.18-0.52). These findings highlight meaningful heterogeneity in IU development during adolescence and its implications for mental health. Regular monitoring of IU may support early identification of adolescents at risk, while interventions targeting IU reduction may help decrease the risk of developing anxiety and depression. Findings should be interpreted cautiously, as all constructs were assessed via adolescent self-report.