 Cognitive behavioral therapy CBT is a brief, efficient, and effective psychotherapy for individuals with depressive and anxiety disorders. However, CBT is largely underutilized within Veteran Affairs Medical Centers VAMCs due to the cost and burden of trainings necessary to deliver the large number of CBT protocols. Transdiagnostic CBT, in contrast, is specifically designed to address numerous distinct disorders within a single protocol. This transdiagnostic approach has the potential to dramatically improve the accessibility of CBT within VAMCs and therefore improve clinical outcomes of Veterans. The proposed research seeks to evaluate the efficacy of a transdiagnostic CBT by assessing clinical outcomes and quality of life in VAMC patients with depressive and anxiety disorders throughout the course of treatment and in comparison to an existing evidence-based psychotherapy, behavioral activation treatment. 