Intolerance of uncertainty as a prospective predictor of generalized anxiety and depression in adolescents: evidence from a three-wave, 12-month study.

AIMS: Intolerance of uncertainty (IU) - a dispositional inability to react effectively to uncertain situations - has been increasingly conceptualized as a transdiagnostic risk factor for internalizing problems such as generalized anxiety and depression. However, evidence for its temporal role in the development of these conditions remains limited, particularly in adolescents, a group at heightened risk for psychopathology.

METHODS: A total of 5,291 adolescents (46.2% boys; M age = 14.40 ± 1.56, range = 10-18 years) completed self-report measures of IU, generalized anxiety and depressive symptoms at baseline, 6 months and 12 months. Linear and logistic regression analyses examined whether baseline IU predicted subsequent symptom severity and elevated (above-cut-off) symptom levels over time.

RESULTS: Higher baseline IU significantly predicted increases in generalized anxiety and depressive symptoms, as well as higher odds of elevated generalized anxiety and depressive symptom levels at both 6- and 12-month follow-ups, even after adjusting for baseline symptom severity or baseline elevated symptom status. Baseline IU also predicted the new-onset and persistence of elevated symptoms across both intervals. Stratified analyses revealed developmental and sex differences: IU's predictive effects were strongest in early adolescence for girls and in middle-to-late adolescence for boys.

CONCLUSIONS: IU emerged as a transdiagnostic longitudinal predictor of generalized anxiety and depressive symptoms in adolescents, supporting its value as an early screening marker of vulnerability. Interventions targeting IU may offer an effective strategy for reducing broad internalizing risk during this critical developmental period.