Although brief interventions have been found to be effective in other populations, their efficacy in an ADHD population with emerging risk for substance use problems remains uninvestigated. This study aims to understand why some adolescents with ADHD and elevated risk for SUD respond to (BEI) and others do not. The investigators will test whether situational and individual characteristics predict substance use development and response to treatment. Further, this study will assess which types of additional treatment are most effective for youth who do not respond to the initial BEI. It is hypothesized that rates of adolescent substance use will be lower among adolescents who participate in study treatments.