Pilot effectiveness trial of an ACT self-help workbook tailored specifically for prisons - PROJECT SUMMARY More than two million individuals are currently incarcerated in correctional facilities in the United States, and over half these individuals have a significant mental health problem. Despite the widespread need for mental health treatment in prisons, resources in this setting are extremely limited and most facilities are unable to provide adequate care. Hence, low-cost and scalable mental health treatment options are urgently needed for the prison population. Self-help workbooks are one such viable option. In non-incarcerated populations, self- help workbooks have shown efficacy in decreasing symptoms of depression, anxiety, and stress, as well as increasing mindfulness and acceptance skills. Moreover, our preliminary data on treatment preferences among incarcerated individuals indicate a preference for self-administered workbooks relative to other treatment formats (e.g., group or individual therapy with counselors). A self-help workbook for Acceptance and Commitment Therapy (ACT) may be particularly well suited to the prison environment. ACT aims to increase psychological flexibility, the ability to choose prosocial and value-based behavior, even if psychological barriers (e.g., anger, shame, maladaptive beliefs, etc.) are present. ACT self-help workbooks have been proven efficacious in reducing mental health burden in non-incarcerated populations. Moreover, studies of ACT group therapy in correctional settings have demonstrated feasibility as well as a variety of positive mental health outcomes. Hence, an ACT self-help workbook may be highly feasible, acceptable, and efficacious format for mental health treatment in the prison setting. The overall goal of this project is to conduct a pilot test of an ACT self-help workbook tailored specifically for the prison setting. Based on feedback from key stakeholders (incarcerated people and prison officials), we will make two main adaptations to the most widely used and empirically supported ACT workbook, in order to make it more acceptable and effective for the prison population: 1) reduce the reading level and 2) increase the personal relevance of the content (e.g., examples and exercises that are relevant to the prison setting). This project features a unique partnership between stakeholders (incarcerated individuals and corrections staff) and academic experts in forensic psychology and ACT. Our proposed research is directly responsive to Funding Opportunity Announcement (FOA) PAR-21-131, as it will adapt and test an intervention with demonstrated efficacy in a broader (and severely underserved) target population. As per the FOA, our study will include a pilot randomized controlled trial (RCT) to test the feasibility and acceptability of the intervention to inform a future larger-scale study. This study is novel in its use of stakeholder input to tailor a self-help intervention specifically for the prison setting. Successful completion of this pilot project will support a future larger-scale RCT evaluating the effectiveness of the workbook in prison. If proven clinically effective, widespread dissemination of the workbook could dramatically increase access to mental healthcare for a severely underserved population.