Substance use treatment; Treatment for co-occurring substance use plus either serious mental health illness in adults/serious emotional disturbance in children; Outpatient; Outpatient day treatment or partial hospitalization; Intensive outpatient treatment; Regular outpatient treatment; Does not use medication assisted treatment for alcohol use disorder; Does not treat opioid use disorders; Medication for mental disorders; Anger management; Cognitive behavioral therapy; Motivational interviewing; Relapse prevention; Substance use disorder counseling; Trauma-related counseling; 12-step facilitation; Private for-profit organization; Private health insurance; Cash or self-payment; Adolescents; Clients who have experienced sexual abuse; Clients who have experienced intimate partner violence, domestic violence; Clients who have experienced trauma; Comprehensive mental health assessment; Comprehensive substance use assessment; Interim services for clients; Complete medical history/physical exam; Screening for substance use; Screening for mental disorders; Drug or alcohol urine screening; Aftercare/continuing care; Discharge Planning; Outcome follow-up after discharge; Mentoring/peer support; Employment counseling or training; Treatment for other addiction disorder; Substance use disorder education; Individual counseling; Group counseling; Family counseling; Marital/couples counseling; Vocational training or educational support (for example, high school coursework, GED preparation, etc.) ; Smoking not permitted; Children/adolescents; Female; Male; Vaping not permitted; Case management service; Mental health services; Social skills development