We collected a set of small nuclear pedigrees suitable for linkage analyses of cocaine dependence and opioid dependence (23, 24). Families were selected on the basis of containing at least two siblings each affected with either cocaine or opioid dependence (or both); recruitment was not conditioned on AD. We have also published results from this sample for nicotine dependence (25). We evaluated these subjects with the SSADDA (Semi-Structured Assessment for Drug Dependence and Alcoholism (23, 26, 27), a polydiagnostic instrument that assesses a range of psychiatric diagnoses, including DSM-IV AD. We describe here the results of a genomewide linkage analysis for AD in the AA families in this clinical sample.
