SER Familia: A Family-Based Intervention Addressing Syndemic Conditions among Latino Immigrant Families - ABSTRACT Latino immigrants experience health inequities that are heightened over time and across generations. In fact, the syndemic (conditions that cluster among marginalized groups) comprised of substance use, intimate partner violence (IPV), risk for HIV, and mental health conditions has been found to increase among Latino immigrants over time and higher levels of US acculturation. Acculturative stress, the stress associated with being a Latino immigrant and acculturating to the US, is the most robust predictor of this syndemic and the impact these stressors have on family level dynamics (e.g., marital stress, acculturation gaps) are particularly harmful. Latino immigrant families have multiple sources of resilience that allow them to resist, recover, and rebound from this stress. These include individual active coping, optimisim in the American Dream, and a positive ethnic identity; family support, parental monitoring and positive parent-child communications; and community social support and access to social and health resources. This application aims to prevent syndemic health conditions by decreasing acculturative stress and promoting resilience via SER Familia (Salud, Estrés y Resilencia en Familias/ Health, Stress, and Resilience in Families), a family-based intervention informed by our observational (SER Hispano; R01MD012249) and pilot studies. SER Familia is a six-session intervention co-developed and delivered by community health workers (CHWs) that uses strategies to reduce acculturative stress, promote resilience, improve parent-child and family level health, while simultaneously helping families maintain strong social networks and better navigate community resources to address social determinants of health (SDOH). More specifically we aim to: 1) Examine the efficacy of SER Familia to prevent or reduce the syndemic comprised of substance abuse, IPV, HIV risk, depression, and anxiety among Parents and Youth; and 2) Identify how individual, family, and community mechanisms of change related to acculturative stress and resilience mediates the effect of SER Familia. We will carry out a community-engaged, mixed-methods, randomized controlled trial with 380 Latino immigrant families to determine the impact of SER Familia compared to a delayed intervention condition. Data from surveys using culturally specific measures of acculturative stress, resilience, and syndemic outcomes collected at baseline, immediately after the intervention, and 6 and 12 month follow-up periods from Parent and Youth dyads will be integrated with interviews with a sub-set of dyads randomized to the SER Familia (n=20) to generate a comprehensive understanding of the impact and mechanisms of the intervention. Our long-term goal is to develop scalable interventions that prevent syndemics and employ multi-level approaches to address acculturative stress and resilience among Latino immigrants in the US. The findings from this study will help identify strategies to promote health for Latino families, the largest minoritized group in the US.