Specific Aim 1: The primary aim of the present research was to adapt and test OPTION-A for use in outpatient settings to treat youth diagnosed with a substance use disorder and comorbid internalizing disorder. We hypothesized that youth receiving OPTION-A would exhibit significantly less drug use (e.g., youth self-reports and urine screens) than control youth who received usual services, and that youth receiving OPTION-A would exhibit significant improvement on indices of mental health (e.g., combined youth and caregiver reports on diagnostic interviews and youth, caregiver, and teacher reports of internalizing symptoms) compared to control youth Specific Aim 2: In addition to improved symptomatology, the current research aimed to test the effectiveness of OPTION-A to improve youth functioning in other domains pertinent to successful adolescent development. We hypothesized that youth receiving OPTION-A would evidence improved behavioral (e.g., youth, caregiver, and teacher reports of externalizing), school (e.g., school attendance), and family functioning (e.g., youth and caregiver reports of family adaptability and cohesion) compared to control youth who received usual services.