RecruitingBehavioural interventionEvaluating an Adverse Childhood Experience-Targeting Advocate Model of a Substance Use Prevention ProgramPrimary Objective: Conduct a rigorous evaluation of a prevention-based intervention designed to mitigate the harms of adverse childhood experiences (ACEs) exposure and prevent future ACEs, substance use, and overdose within 36 communities experiencing a disproportionate burden of substance use and ACEs. The study has three aims: (1) use a cluster randomized controlled trial to test effectiveness of the Strengthening Families Program (SFP) + Family Advocate (FA) intervention on substance use, overdose, and ACEs in 18 communities compared with SFP-only in 18 communities; (2) conduct a robust process evaluation informed by the Consolidated Framework for Implementation Research (CFIR) to explore implementation barriers and facilitators; and (3) conduct a cost evaluation to accurately estimate the costs required to implement SFP and SFP+FA and assess the cost-effectiveness of SFP+FA relative to SFP alone. Findings will provide a roadmap about the best ways to help disproportionately affected communities prevent substance use, overdose, and ACEs.