Study protocol for Hastiin Bidziil (Strong Man): a randomized controlled trial of a strength-based, culturally adapted intervention for substance use reduction among American Indian men

Substance use disorder (SUD) in American Indian and Alaska AI (AI/AN, or “AI”) communities remains a persistent public health concern. AI/AN men experience high rates of substance use, along with related health conditions, mental health challenges, and premature mortality. Despite these concerns, research and public health efforts addressing AI/AN men’s health, particularly through culturally grounded approaches, remain limited. To address this gap, a culturally adapted secondary prevention intervention, Hastiin Bidziil (Strong Man), was developed for AI men to reduce substance use. The intervention is based on the Common Elements Treatment Approach (CETA), a transdiagnostic mental health intervention. The AI/AN-led study team facilitated a formative process where the evidence-based CETA model was adapted for rural AI men through the ADAPT-ITT approach, resulting in the Strong Man intervention. The randomized controlled trial will evaluate the effectiveness of the Strong Man intervention among 160 adult AI men. Participants are randomly assigned to either the Strong Man intervention or a basic vehicle maintenance control group. The intervention consists of a 6-lesson skill-building curriculum (minimum 5, maximum 8 sessions) incorporating cognitive behavioral therapy, motivational interviewing, and harm reduction components. The control group receives four workshops on basic vehicle maintenance, with the option to access the intervention as a service after study completion. Assessments occur at baseline, post-intervention, or control completion (or 6 months post-baseline, whichever comes first), and at an 8-month follow-up. The primary outcome is substance use frequency over the past 14 days. Secondary outcomes include substance use involvement, depression, anxiety, and post-traumatic stress disorder. Mixed-effects models will be used to evaluate intervention effects. This trial represents one of the first rigorous evaluations of a culturally adapted secondary prevention program for rural AI men. By intervening before substance use escalates, Strong Man has the potential to reduce substance-related harms, strengthen protective behaviors, such as culturally grounded coping strategies, community, connectedness, and mental well-being. Findings will inform scalable, community-driven strategies that reduce substance-related harm in tribal communities. ClinicalTrials.Gov NCT06559774.