Developed scoring routines were applied to independent GWAS data for EA (n = 1,573) and AA (n = 841) case-control subjects from the Study of Addiction: Genetics and Environment (SAGE) (Bierut et al. 2010). For this data set, AD cases and non-dependent controls were selected from three large, complementary studies: COGA, Family Study of Cocaine Dependence (FSCD), and Collaborative Genetic Study of Nicotine Dependence (COGEND). All COGA subjects were excluded to ensure independence between the discovery and target samples (although it should be noted that not all of the cases from the COGA case-control study were a part of SAGE). Cases (n = 958) were identified as having a lifetime history of AD using DSM-IV criteria. Control subjects (n = 1,456) were required to report a history of drinking and have no significant AD symptoms or any other substance dependencies. The Institutional Review Board at each contributing institution approved the protocols, and all subjects provided written informed consent for genetic studies.
