Project Summary There is a fundamental gap in delivery of evidence-based interventions to improve the promotion of physical activity in individuals with depression. Despite its proven efficacy in randomized control trials, exercise (i.e., increasing physical activity) is rarely used as a treatment for depressive disorders in real-world clinical settings. Our proposed intervention addresses shortcomings in previous research by developing a briefer intervention and delivering the intervention via teletherapy, both of which aim to reduce barriers to intervention adherence. The long-term goal is to improve treatment outcomes and physical health of persons with depression through increasing physical activity. The overall objective of this project is to conduct a pilot study of an adapted Behavioral Activation intervention that aims to improve depression treatment outcomes by specifically targeting physical activity. The central hypothesis is that such an intervention can be developed for depressed individuals and is feasible to deliver through teletherapy. In order to fill the gap in knowledge and unmet need, we will pursue the following two specific aims: 1) Refine and evaluate an existing, manualized behavioral activation intervention that specifically targets physical activity-based activities by gathering focus group and semi-structured interviews and exit surveys from participants, partial-completers and non-initiators and 2) Determine the feasibility and acceptability of intervention delivery and conduct a preliminary analysis of intervention efficacy by measuring recruitment and retention, intervention adherence, and evaluating changes in depressive symptoms and physical activity as distal and proximal intervention outcomes, respectively. We also evaluate the intervention’s mechanism of action using RDoC-based criteria and include an exploratory aim, analyzing minimum number of completed therapy sessions needed to achieve depression remission. Successful completion of the proposed study aims move the field forward by providing empirical evidence for shortening established Behavioral Activation interventions and demonstrating feasibility of recruitment from and intervention delivery to patients referred from real-world clinical practice, thus expanding the intervention’s reach and impact and informing scalability. This project also informs subsequent R01 grants to (a) conduct a randomized control trial with the refined intervention against a control group and (b) a subsequent project testing implementation science principles – i.e. multiple kinds of interventionists (unlicensed versus licensed master’s level), settings (interventionist at home versus embedded in primary care) and delivery platforms (video versus telephone) – so as to create a scalable and sustainable intervention embedded in existing reimbursable service delivery mechanisms. The current project has the potential to increase care access for patients, especially those with low SES...