PROJECT SUMMARY/ABSTRACT Despite consistently high rates of Post-Traumatic Stress Disorder (PTSD) in persons living with HIV (PLWH) and the alarmingly poor HIV-related health outcomes associated with PTSD, an effective evidence-based treatment for reduction of PTSD symptoms in PLWH does not exist. Negative reinforcement conceptual models posit that avoidant behavior (a hallmark symptom of PTSD) demonstrated by PLWH with co-occurring PTSD can contribute to poor antiretroviral therapy (ART) adherence. However, research evaluating the impact of evidence-based treatment for PTSD among HIV infected populations on HIV outcomes is scarce. The Cognitive Processing Therapy (CPT) protocol is an evidence-based PTSD treatment that may also address HIV-related intersectional stigma with targeted modifications and improve ART adherence and subsequent viral suppression through reduction of avoidant coping. The proposed 3 year study will leverage infrastructure through the Ryan White network and be the first pilot RCT to test feasibility of an integrated evidence based PTSD treatment (CPT) with an adherence intervention (Lifesteps) delivered in a Ryan White clinic to improve PTSD symptoms, adherence to ART, and retention in HIV care. The specific aims are: 1) To deliver un- adapted CPT and Lifesteps with 12 PLWH with co-occurring PTSD and collect qualitative feedback to maximize acceptability and relevance of the integrated CPT-L protocol; 2) To determine feasibility of the modified CPT protocol using a randomized controlled 2 (treatment type) x 3 (time points) trial design in 60 PLWH with comorbid PTSD exploring impact of CPT-L on PTSD symptoms, avoidant coping (posited mechanism of action), substance use, depression, ART adherence, CD4 count, viral load, and engagement in care compared to a Lifesteps +Standard of Care condition. In Aim 1, qualitative data from theater testing and exit interviews collected after 12 cases of beta testing and feedback from the Community Advisory Board and topical experts will inform refinement of the research protocol. In Aim 2, CPT-L will then be piloted with 60 PLWH meeting PTSD diagnostic criteria. Participants will be randomized to the control condition (Lifesteps+ SOC; N=30) or the intervention condition (CPT-L; N=30) and will complete assessments at baseline, post- intervention (6 weeks), and 3 months post-randomization. Specific feasibility benchmarks (e.g., retention, fidelity, satisfaction) will be examined and variability of estimates will be obtained. This data are critical to informing an R01 application for rigorous evaluation of CPT-L as a vehicle for improving ART adherence and retention in care. If successful, this research extends PTSD treatment approaches as a paradigm to reduce barriers to ART adherence, which is an innovative use of established behavioral interventions and significant because results support the U=U campaign and can help prevent the transmission of HIV infection through increased viral suppres...