Univariate GCTA-GREML analyses were performed to estimate the SNP-based heritability of alcohol consumption in the whole UKB sample and then for males and females separately. A genetic relationship matrix was created for an unrelated subsample using a cutoff of 0.025 (N=89 175) and used to estimate heritability.31, 32, 33 The genetic correlation between male and female alcohol consumption was estimated using LD score regression following the pipeline designed by Bulik-Sullivan et al.34 This method exploits the correlational structure of SNPs across the genome and uses test statistics provided from GWAS summary estimates to calculate the genetic correlations between traits.35 False discovery rate was used to correct P-values for multiple testing. We supplied the GWAS summary statistics from the GWAS of male and female alcohol consumption. Using our GWAS summary statistics, the genetic overlap between alcohol consumption and over 200 other disease traits was assessed using LD score regression34 implemented in the online software LD Hub (http://ldsc.broadinstitute.org/).36
