SUBSTANCE ABUSE (1,000) illicit drugsprescription drugmental illnesssubstance use problemsalcohol abusesubstance use disordersunited statessubstance abuse problemssubstance abuse and mental health services administrationwashington dcdepartment of health and human servicesnational institute on drug abusehealth problemsmillion peopleabused drugssubstance abuse treatmentillegal drugslong termpublic healthhealth care