Substance use treatment; Treatment for co-occurring substance use plus either serious mental health illness in adults/serious emotional disturbance in children; Outpatient; Intensive outpatient treatment; Regular outpatient treatment; Does not use medication assisted treatment for alcohol use disorder; Does not treat opioid use disorders; Anger management; Cognitive behavioral therapy; Relapse prevention; Substance use disorder counseling; Private for-profit organization; State Substance use treatment agency; Private health insurance; Cash or self-payment; Clients with co-occurring mental and substance use disorders; Comprehensive mental health assessment; Comprehensive substance use assessment; Discharge Planning; Individual counseling; Smoking not permitted; Children/adolescents; Female; Male; Specially designed program for DUI/DWI clients; Mental health services