A total of 7,543 subjects were aggregated from family-based and case-control genetic studies of substance dependence (primarily cocaine and opioid dependence and, to a lesser extent, alcohol dependence). Affected subjects were recruited following telephone screening that indicated the presence of a cocaine, opioid, or alcohol dependence diagnosis. Controls were recruited after screening indicated the absence of a major psychiatric or substance use disorder diagnosis. Subjects were recruited at five sites: Yale University School of Medicine (n=3,223), the University of Connecticut Health Center (n=2,996), the University of Pennsylvania School of Medicine (n=726), the Medical University of South Carolina (n=475), and McLean Hospital (n=122). Only probands from the small nuclear families that participated in the genetic studies were included in the present analyses.
