The trajectories of adolescent anxiety and depressive symptoms over the course of a transdiagnostic treatment.

Anxiety and depressive disorders commonly co-occur during adolescence, share multiple vulnerability factors, and respond to similar psychosocial and pharmacological interventions. However, anxiety and depression may also be considered distinct constructs and differ on some underlying properties. Prior research efforts on evidence-based treatments for youth have been unable to examine the concurrent trajectories of primary anxiety and depressive concerns across the course of treatment. The advent of transdiagnostic approaches for these emotional disorders in youth allows for such examination. The present study examined the separate trajectories of adolescent anxiety and depressive symptoms over the course of a transdiagnostic intervention, the Unified Protocol for the Treatment of Emotional Disorders in Adolescence (UP-A; Ehrenreich et al., 2008), as well as up to six months following treatment. The sample included 59 adolescents ages 12-17 years old (M=15.42, SD=1.71) who completed at least eight sessions of the UP-A as part of an open trial or randomized, controlled trial across two treatment sites. Piecewise latent growth curve analyses found adolescent self-rated anxiety and depressive symptoms showed similar rates of improvement during treatment, but while anxiety symptoms continued to improve during follow-up, depressive symptoms showed non-significant improvement after treatment. Parent-rated symptoms also showed similar rates of improvement for anxiety and depression during the UP-A to those observed for adolescent self-report, but little improvement after treatment across either anxiety or depressive symptoms. To a certain degree, the results mirror those observed among other evidence-based treatments for youth with anxiety and depression, though results hold implications for future iterations of transdiagnostic treatments regarding optimization of outcomes for adolescents with depressive symptoms.