Anticipated Impacts on Veterans Healthcare: Findings have the potential to increase the number of Veterans who benefit from one of the most effective treatments for posttraumatic stress disorder (PTSD), Cognitive Processing Therapy (CPT). In addition to reductions in PTSD symptomology, successful completion of CPT results in improvement in functional impairment, decreases in comorbid symptoms, and enhanced quality of life. This project tackles an important question for our colleagues within the Office of Mental Health and Suicide Prevention, who have expressed a need for strategies that enable flexibility while maintaining fidelity to the demonstrably efficacious CPT protocol. This proposal addresses RR&D’s priority area of conducting research on cognitive behavioral therapy for Veterans with psychological health conditions. Project Background: CPT has been widely disseminated throughout VHA with over 4000 VHA providers certified to provide CPT through the Mental Health Dissemination Initiative to date. However, as CPT has been implemented several factors have limited its impact on Veterans’ health. Veteran engagement in CPT is suboptimal, outcomes achieved in Veteran populations are more modest than those obtained with civilians, and improvements in functioning and quality of life are more modest than those observed in the core symptoms of PTSD. Strategies for improving patient engagement, enhancing treatment outcomes, and expanding the success of the intervention to functional impairments are needed for Veterans to fully benefit from the CPT dissemination initiative. Expanding and enhancing the CPT protocol is a promising strategy for achieving these goals. Integrating a case formulation (CF) approach into the existing CPT protocol may enable providers to increase treatment flexibility while maintaining fidelity to effective CPT principles. CF is a collaborative process between providers and patients that enables providers to tailor cognitive-behavioral treatments to specific clients’ needs within clear parameters of what justifies deviation from the standard protocol. Our study team has preliminarily demonstrated that CF-integrated CPT (CF-CPT) yields lower levels of dropout and a higher proportion of patients losing their PTSD diagnoses than published accounts of CPT. Project Objectives: Our long-term objective is to build on the success of the CPT Dissemination Initiative on Veterans’ health by directly targeting functional impairments and enhancing patient outcomes. We propose the following aims: 1) Compare the relative effectiveness of CF-CPT to CPT in improving Veterans’ psychosocial functioning quality of life and well-being as well as core PTSD and depression symptoms; 2.) Determine the effectiveness of CF-CPT as compared to CPT in improving Veterans’ treatment engagement; 3.) Evaluate CF- CPT’s indirect impact on Veterans’ psychosocial functioning, quality of life, well-being and PTSD/depression as influenced by improvement in the idio...