age 35.0 ± 11.0 yr) and 91 controls (77 females (mean age 35.1 ± 11.4 yr) / 14 males (mean age 42.5 ± 12.3 yr)]. All subjects were of substantial African descent and all provided written informed consent as approved by the institutional review board at each institution. The race of all subjects was defined according to self-identification and confirmed by Bayesian model-based clustering using genetic marker information (Gelernter et al., 2005). Psychiatric diagnosis was based on responses obtained using the Semi-Structured Assessment for Drug Dependence and Alcoholism (SSADDA) (Pierucci-Lagha et al., 2005) or the Structured Clinical Interview for DSM-IV disorders (SCID) (Spitzer et al., 1992; Williams et al., 1992).
