Next, since impulsiveness has been associated with alcohol problems, we also tested the association of these SNPs with the Lifetime Alcohol Problems Score (LAPS). Four SNPs, including the most strongly associated SNP mentioned above, spanning the region from intron 3 to intron 4 were associated with LAPS (Table 2). Although, none of these SNPs survive multiple testing, we consider important to report this association for the mediation analysis that follows. As expected, the association was in the same direction, i.e. alleles associated with higher scores of impulsiveness were also associated with higher scores of LAPS (Table 2). The effect size of these SNPs varies between 2.4% and 2.5%, somewhat lower than the effect size for impulsiveness. Again SNP rs279827 showed one of the strongest effects on LAPS (2.5%). Gender, age and race as covariates were not significant and were not included in the final model. However, as expected LAPS scores were significantly higher in the AUD group (12.5 ± 2.1) compared to the non AUD subjects (8.9 ± 1.9) (p < 0.00001). Figure 1 depicts the location of the four
