PROJECT SUMMARY/ABSTRACT Allogeneic stem cell transplantation is a potentially curative treatment for some hematologic malignancies, and it often requires a 3-4-week hospitalization. Notwithstanding the promising nature, the transplantation process and recovery is intensive and fraught with potential life-threatening complications during acute and long-term recovery. Hence, allogeneic transplant recipients have a high burden of psychological distress, and quality of life (QOL) deficits are common. Most efforts to achieve optimal psychological well-being in this population have targeted the reduction of distress symptoms (e.g., depression and anxiety). However, positive psychological well-being (e.g., optimism, positive affect) can buffer against this distress and has been prospectively associated with improved QOL, physical functioning, and survival in allogeneic transplant patients. Positive psychological interventions (PPIs), which utilize systematic activities (e.g., recalling positive life events, using personal strengths) to promote psychological well-being, have consistently and durably enhanced psychological health and QOL in medical settings, but have never been used in allogeneic transplant patients. Given the need for new programs to promote well-being and recovery after allogeneic transplantation, the proposed project will develop and test a novel PPI in allogeneic transplant recipients, PATH (Positive psychology for Allogeneic Transplantation of Hematopoietic stem cells), to fill this unmet need. Principal Investigator Dr. Amonoo will develop the PATH intervention via a review of the literature and application of a theoretical framework and test its acceptability (via quantitative participant ratings and qualitative feedback at exit interviews) in a one-arm proof- of-concept trial (N=10; Aim 1). Next, Dr. Amonoo will test the feasibility (primary outcome) and preliminary efficacy of the PATH intervention (refined using Aim 1) on psychological, functional, and behavioral outcomes in a pilot randomized controlled trial with 70 allogeneic transplant recipients (Aim 2). Finally, in Aim 3, Dr. Amonoo will use individual semi-structured interviews with Aim 2 pilot trial participants and 20 oncology clinicians to explore the facilitators and barriers to implementing PATH in clinical settings. This project will facilitate training essential to Dr. Amonoo’s research career goals: intervention development, clinical trial design and execution, advanced biostatistics, and implementation science. Dr. Amonoo has assembled dedicated mentors who are renowned researchers with complementary expertise: PPI trials in medical populations (primary mentor: Jeff Huffman, MD), supportive oncology interventions (co-mentor: Areej El-Jawahri, MD), quantitative methods (co- mentor: William Pirl, MD), implementation science (co-mentor: Elyse Park, PhD, MPH), and biostatistics (research advisor: Brian Healy, PhD). Dr. Amonoo’s mentorship will be supplemented by str...