Substance use treatment; Treatment for co-occurring substance use plus either serious mental health illness in adults/serious emotional disturbance in children; Outpatient; Regular outpatient treatment; No formal relationship with prescribing entity; Does not use medication assisted treatment for alcohol use disorder; Accepts clients using MAT but prescribed elsewhere; Brief intervention; Cognitive behavioral therapy; Dialectical behavior therapy; Motivational interviewing; Relapse prevention; Substance use disorder counseling; Trauma-related counseling; Private for-profit organization; State mental health department; Federal, or any government funding for substance use treatment programs; Cash or self-payment; Adolescents; Young adults; Adult women; Adult men; Veterans; Criminal justice (other than DUI/DWI)/Forensic clients; Clients with co-occurring mental and substance use disorders; Clients who have experienced intimate partner violence, domestic violence; Clients who have experienced trauma; Comprehensive substance use assessment; Screening for substance use; Screening for mental disorders; Aftercare/continuing care; Discharge Planning; Outcome follow-up after discharge; Substance use disorder education; Individual counseling; Family counseling; Marital/couples counseling; Smoking not permitted; Female; Male; Case management service; Domestic violence services, including family or partner; Mental health services; Social skills development