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; Does not treat alcohol use disorder; Does not treat opioid use disorders; Anger management; Cognitive behavioral therapy; Motivational interviewing; Private non-profit organization; State mental health department; Medicare; Medicaid; Cash or self-payment; Adolescents; Young adults; Adult men; Seniors or older adults; Lesbian, gay, bisexual, transgender, or queer/questioning (LGBTQ); Veterans; Clients with co-occurring mental and substance use disorders; Clients who have experienced trauma; Comprehensive mental health assessment; Comprehensive substance use assessment; Screening for mental disorders; Drug or alcohol urine screening; Individual counseling; Smoking not permitted; Children/adolescents; Seniors; Female; Male; Case management service; Mental health services