Investigators will conduct a two-arm, comparative effectiveness randomized controlled trial of two culturally adapted, empirically based programs (EBP) - Narrative Exposure Therapy (NET) vs. Motivational Interviewing with Skills Training (MIST) in terms of lowering HIV sexual-risk behaviors (HSB) for American Indian / Alaska Native (AIAN) men and women. NET addresses Posttraumatic Stress Disorder (PTSD) as a pathway to preventing substance use disorders (SUD) and HSB whereas MIST addresses substance misuse as a way of preventing SUD and HSB.