We used genome-wide complex trait analysis (GCTA) to calculate the heritability for the OUD phenotype. Common SNPs explained 0.06 of the phenotypic variance in our OUD phenotype (se 0.02, p=6.75×10−3). We then calculated pair-wise genetic correlations between OUD and two other major substance use disorders, alcohol and nicotine use disorders, which were also derived from Partners Biobank using similar diagnostic information (Table 1). For those two traits, heritability analysis showed common SNPs explained 0.12 of the phenotypic variance in alcohol use disorder (se 0.02, p=4.25×10−9) and 0.11 of the phenotypic variance in nicotine use disorder (se 0.02, p=6.64×10−8). We observed significant correlations of 0.65 (se=0.19, p=4.82×10−4) between nicotine and opioid use disorders and 0.59 (se=0.18, p=1.28×10−3) between alcohol and opioid use disorders (Table 5).
