Table 2 presents SNP-heritability and correlation estimates from the bivariate analyses. As expected, the three phenotypes had high phenotypic correlations, ranging from 0.84 to 0.86. A strong significant SNP-correlation was observed from bivariate analyses between DD and DV (rSNP = 0.97, SE = 0.08) and strong SNP-correlations were found between DD and PU (rSNP = 0.92, SE = 0.08) and between PU and DV (rG = 0.96, SE = 0.07). This suggested that the different ways of scoring substance dependence or vulnerability to substance dependence are associated with largely overlapping SNPs.
