The predictive power and accuracy of PRS depends largely on the statistical power of the discovery GWAS and the genetic ancestral similarities between the discovery and target samples (Duncan et al., 2019; Martin et al., 2019; Peterson et al., 2019). We calculated alc-PRS for EAs using estimates from a GWAS of alcohol use (drinks per week) in nearly 1 million individuals of European ancestry from the GWAS and Sequencing Consortium of Alcohol and Nicotine Use (Liu et al., 2019), one of the largest GWAS on alcohol-related phenotypes among EAs to date. We constructed alc-PRS for EAs using the PRS-CS method, a Bayesian regression and continuous shrinkage prior method shown to improved predictive power above traditional methods of PRS construction (Ge et al., 2019). An average of 2,069,117 SNPs was included in the construction of alc-PRS for EAs. For AAs, we used estimates from the GWAS of alcohol consumption (AUDIT-C) in the Million Veterans Project (MVP) sample (Kranzler et al., 2019), the largest published GWAS of alcohol phenotypes with a multiancestry sample including 209,020 EAs and 57,340 AAs. We calculated alc-PRS
