A total of 9,965 identically evaluated subjects were aggregated from family-based and case–control genetic studies of DSM-IV CD, opioid dependence (OD), and alcohol dependence (AD). Subjects were recruited at five sites: Yale University School of Medicine (N = 4,450, 44.7%), University of Connecticut Health Center (N = 3,698, 37.1%), University of Pennsylvania Perelman School of Medicine (N = 968,9.7%), Medical University of South Carolina (N = 596, 6.0%), and McLean Hospital (N = 253, 2.5%). Subjects with a clinical diagnosis of schizophrenia, bipolar disorder, or gross cognitive impairment were excluded. The institutional review board at each site approved the study protocol and informed consent forms. The National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism each provided a Certificate of Confidentiality to protect participants. Subjects were paid for their participation.
