Experiential Avoidance Predicts Persistence of Major Depressive Disorder and Generalized Anxiety Disorder in Late Adolescence

OBJECTIVE: Experiential avoidance (EA) is a transdiagnostic construct that may underlie the high comorbidity between major depressive disorder (MDD) and generalized anxiety disorder (GAD). This analysis used data from a longitudinal study (conducted September 2010-April 2016) to examine whether adolescent EA varies by MDD and GAD symptomatology trajectory and predicts said trajectories. Longitudinal associations between EA, anxiety, and depression symptoms were also examined. METHODS: Adolescents aged 15 to 20 years (N = 183) were followed for 2 years using a comprehensive assessment battery. Symptom trajectory modeling, using weekly symptom ratings, identified 4 MDD and 4 GAD trajectories that were collapsed to form combined MDD/GAD trajectory groups: Persistent (n = 81), High-Decreasing (n = 44), Normal-Increasing (n = 37), and Minimal (n = 21). Group-based trajectory modeling, analyses of covariance, structural equation modeling, and linear regression analyses were performed. DSM-IV-TR criteria were used for MDD and GAD diagnoses. RESULTS: The Persistent adolescents had higher EA than other groups (P values ≤ .001), with greater EA stability versus High-Decreasing adolescents (P = .008). EA predicted anxiety and depressive symptoms alike (P values ≤ .005), which in turn did not predict EA (P values ≥ .188). EA, at both time points, predicted combined MDD/GAD trajectories after adjustment for depressive and anxiety symptoms and other confounders (P values < .001). CONCLUSIONS: EA appears to be an important predictor of MDD and GAD symptomatology in older adolescents, potentially serving as a treatment target. Findings suggest a possible trait-like nature for EA, perhaps increasing risk for the emergence and persistence of MDD and/or GAD. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02147184​.