In addition, and contrary to our expectation, in the AA sample children’s genetic risk for alcohol problems, as indexed with genome-wide polygenic scores, was not associated with initiation of regular drinking and AUD. Furthermore, we did not find evidence for an interaction between parental divorce/discord and PRS on either a multiplicative or additive scale in the African ancestry sample. These null findings are likely attributable to the limited predictive power of polygenic scores in individuals of African ancestry. Predictive power of polygenic scores is largely dependent on matching ancestry between the discovery sample and the independent target sample as well as the sample size of discovery GWAS (Martin et al., 2017). However, populations of non-European ancestry, particularly those of African ancestry, have been historically underrepresented in genome-wide association studies across the field (Popejoy & Fullerton, 2016) and limiting our ability to create well-powered polygenic scores in this ancestral population. Although we attempted to mitigate this issue with the PRS-CSx (Ruan et al., 2022) method, which integrates GWAS summary statistics of European ancestry and African ancestry populations to improve the performance
