Evaluation of a transdiagnostic treatment for adolescents with comorbid anxiety and depression

Abstract Background Evidence suggests that adolescents with comorbid anxiety and depression are a high-risk group in terms of symptom severity, life quality and prognosis, with unique treatment needs compared to their peers who meet criteria for a single diagnosis. The current study evaluated the efficacy of a transdiagnostic treatment designed specifically to target shared mechanisms underlying comorbid anxiety and depression in adolescents. Method Eighty-two adolescents (12-17 years) with a concurrent diagnosis of an anxiety and a mood disorder were randomly allocated to either active treatment or wait-list. Effects on diagnoses, symptoms and life interference were assessed at post-treatment, 6- and 12-month follow-up based on reports from both the young person and parents. Results Compared to waitlist, treatment was associated with a significantly greater reduction in total number of diagnoses and clinician rated severity of diagnoses over time. Life interference also showed significantly greater improvement in active treatment compared to wait-list, however other self and parent-reported indicators improved significantly but similarly over time in both groups. Effects were maintained at 6- and 12-month follow up. Conclusions The transdiagnostic package targeting common underlying mechanisms demonstrated reductions in anxiety and depression in adolescents on key measures, including diagnostic criteria and life interference and shows promise as an efficacious treatment for comorbid anxiety and depression in adolescents. The outcomes point to a valuable initial program for clinical use, although further development will be needed to strengthen effects.