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.
Inclusion Criteria: * 16 years old or older * Native American * At least sub-threshold PTSD * Substance use in the previous 12 months * Any lifetime sexual activity Exclusion Criteria: * Suicidal ideation, plan, or attempt in the previous 30 days * Homicidal ideation in the previous 3 months * Psychiatric medication that has not been stable for at least 2 months * A DSM-5 alcohol dependence diagnosis with severe withdrawal symptoms