Adolescence is associated with high risk for suicidal thoughts and behaviors (STBs). In recent years, racial disparities in risk for STBs have become increasingly evident, with African American and other Black-identifying adolescents (herein, Black) experiencing higher rates of suicidal behavior than any other racial group of youth in the U.S. Thus, there is a need for culturally appropriate interventions that target risk factors for STBs among a growing population of racially diverse youth. Anhedonia, defined as the loss of interest or pleasure in enjoyable or valued activities, is a core feature of depression and an independent risk factor for STBs in youth. Behavioral Activation (BA) therapy is a cognitive behavioral intervention that directly targets anhedonia, by decreasing avoidance and isolation behaviors, using positive reinforcement to increase engagement in valued activities and the experience of reward. Growing evidence supports the effectiveness of BA for adolescents in the traditional face-to-face psychotherapy format, and BA has shown promise in the few preliminary investigations that included racially diverse youth. A key advantage of the BA model is that the focus on behavioral strategies is well suited for adaptation to digital platforms that incorporate mobile sensing and can generate objective data on activity. As the digital BA approach allows for real-time feedback to both users and providers on treatment goals and behavioral targets, it offers a significant advantage over traditional face-to-face intervention. To date, no studies have tested digital BA in a diverse study population that includes Black youth. The goal of this study, therefore, is to tailor and test a health coach supported, digital BA intervention to target anhedonia in a diverse sample of youth, using leading implementation science frameworks. The initial BA platform was developed by the investigators to collect mobile accelerometer and geospatial activity data using smartphone technology that is shared with a health coach or clinician to provide feedback and push BA intervention content via a smartphone app. We will first use the Consolidated Framework for Implementation Research (CFIR) to collect and analyze qualitative data from focus groups with racially diverse adolescents, caregivers, providers, and administrators on their perspectives of intervention needs and barriers and facilitators to BA intervention and implementation strategies. Next, using human-centered design methods, we will iteratively develop and adapt the BA intervention to the needs of racially diverse, at-risk adolescents. We will then conduct a pilot randomized trial comparing the digitally delivered BA intervention to passive, smartphone-based activity monitoring alone. A group of 75 adolescents (35% Black), ages 12-18, with moderate depression and elevated anhedonia symptoms will be recruited from the Signature R01. We will examine feasibility, acceptability, and impact on anhedonia ...