PROJECT SUMMARY/ABSTRACT Background: Nearly two-thirds of adolescents and young adults living with HIV (AYALHIV) in Zambia have virologic failure. To date, limited research has assessed the role of developmental factors in achieving positive HIV self-management behaviors and favorable health outcomes among AYALHIV. A comprehensive understanding of these factors is essential to respond to the HIV epidemic among this high-priority population. Study Goal and Aims: Leveraging a parent study that tests the AYALHIV-caregiver Family Connections intervention in Zambia, the proposed research will validate and assess a measure of adolescent development – emotion regulation – in relation to virologic failure, ART adherence, and family and social factors. Specific aims are: 1) Validate the Difficulties in Emotion Regulation Scale (DERS-SF) among AYALHIV in Zambia; 2) Examine associations between emotion dysregulation and a) virologic failure and b) incomplete ART adherence, assessing moderation and mediation by family and social factors; and 3) Use dyadic in-depth interviews with AYALHIV and caregivers to explore relationships identified in Aim 2 between emotion regulation and HIV self-management, and experiences with the Family Connections intervention, comparing AYALHIV with and without emotion regulation difficulties. Approach: Aims 1 and 2 of the proposed research will use secondary questionnaire data collected at baseline by the parent study; Aim 2 also uses measures of virologic status (blood draw) and ART adherence (urine point of care test). In Aim 1, a hierarchical confirmatory factor analysis will be used to validate the DERS-SF. Aim 2 will use structural equation modeling (SEM) to assess relationships between the DERS-SF, virologic status, and moderation and mediation by family and social factors; secondarily, a similar SEM be used to assess relationships with ART adherence. Aim 3 involves primary qualitative data collection with AYALHIV/ caregiver dyads, and will use an inductive approach to gain a nuanced understanding of Aim 2 relationships and AYALHIV's intervention experiences, comparing youth with and without emotion regulation difficulties. Fellowship Information: The proposed research is the doctoral dissertation of Ms. Kathleen Ridgeway, a PhD student at the Johns Hopkins Bloomberg School of Public Health. Ms. Ridgeway's research and training will be supported by experts in adolescent HIV research, qualitative methods, and advanced statistical analysis and includes one Sponsor, two co-Sponsors, and two Scientific Advisors. A combination of didactic coursework, mentorship, independent study, and practical experience will further Ms. Ridgeway's career goal to become a leading independent researcher in adolescent health and HIV. This proposal directly responds to the NIH Program Announcement (PA-18-651) and Notice of Special Interest (NOT-MH-20-035) for developmentally tailored HIV prevention and care research for adolescents and young adult...