Given the frequent comorbidity of anxiety and depression, it is important to study the effects of depression interventions on anxiety and the impact of comorbid anxiety on depression outcomes. This article reports on pooled anxiety and depression data from two randomized trials of Interpersonal Psychotherapy-Adolescent Skills Training (IPT-AST), a depression prevention program. Ninety-eight adolescents were randomized to receive IPT-AST or school counseling (SC). Outcome and predictor analyses were performed utilizing hierarchical linear models. IPT-AST adolescents had significantly greater reductions in anxiety and depressive symptoms than SC adolescents during the intervention. Baseline anxiety symptoms predicted change in depressive symptoms for adolescents in both intervention conditions, with adolescents low in baseline anxiety demonstrating more rapid change in depressive symptoms than adolescents high in baseline anxiety. These findings indicate that IPT-AST is effective at decreasing both depressive and anxiety symptoms. For adolescents with comorbid symptoms of anxiety, there may be slower rates of change in depressive symptoms following prevention programs.