Data from a national sample of patients with a primary diagnosis of a substance use disorder were analyzed to examine whether having a comorbid psychiatric diagnosis-a dual diagnosis-was associated with increased costs of health services over a six-year period and whether dually diagnosed patients used particular types of services more frequently.
Veterans Affairs Connecticut-Massachusetts Mental Illness Research, Education, and Clinical Care Center in West Haven and Yale University School of Medicine in New Haven, West Haven 06516, USA. hoff@biomed.med.yale.edu
