In an effort to assess the utility of the genetic factor score, we also examined the association between DRD2/ANKK1 SNPs and the individual phenotypic measures of alcohol consumption and problems. As the inclusion of seven outcomes required a more stringent statistical test correction, no SNP passed the significance threshold put forth to correct for the multiple tests conducted. These results may suggest that we are indeed reducing genetic heterogeneity in the alcohol measures using the genetic factor scores. Additionally, we increase power to detect association in reducing the number of phenotypes examined (we correct for the analysis of two factor scores versus seven measures of alcohol consumption and problems). Thus, one can increase power to detect genetic association by (1) reducing the number of tests conducted, and (2) modeling the genetic architecture of the trait/disorder within your sample. Further, the need to refine these phenotypes to obtain adequate power to demonstrate association argues against claims of robust association between DRD2/ANKK1 and alcohol dependence. These results should be considered in light of several limitations. First, the generalizability of these results may
