DNA samples were acquired through the NIDA Center for Genetic Studies in conjunction with Washington University and Rutgers University Cell & DNA Repository. Samples from opioid-dependent subjects were acquired from the NIDA Repository Studies 1 (PI: J. Gelernter et al.)[N=313], 5 (PI: M.J. Kreek)[N=491], 17 (PI: W.H. Berrettini)[N=47] and 24(PI: W.H. Berrettini)[N=668] and samples from cocaine dependent subjects were acquired from Studies 7 (PI: L. Bierut)[N=541] and 13 (PI: J. Cubells)[N=133]. Opioid addicted (EA: n=1008; male 66.1%; AA: n=336 male 68%) and cocaine addicted subjects (EA: n=336; male 50.3%; AA: n=681; male 62%) of EA and AA descent met DSM-IV criteria for dependence and were genotyped for this study.
