Phenome-wide association studies (PheWAS) are also characterizing SUD by studying genetic variants that influence use of multiple substances as well as those shared between SUD and non-SUD outcomes. PheWAS refers to a post-GWAS genotype-phenotype association study using datasets which have collected a substantial amount of phenotypic data (phenome; Roden and Denney 2016). PheWAS use a small number of previously identified variants and check their association across the full phenome or with a full completment of traits or measures that are related to the outcome (Bush, Oetjens, & Crawford, 2016). Therefore, PheWAS have the potential to deepen genomic knowledge regarding the range of phenotypic effects associated with GWAS-identified risk alleles. For example, a PheWAS of smoking and alcohol use in 26,394 women replicated prior asosciations between variants in ADH1B and alcohol use (e.g., alcohol servings per week, number of medium servings of wine per day, number of drinks of alcohol) as well as between variants in CHRNA3-CHRNA5 and smoking behaviors (e.g., cigarettes per day, age starte smoking cigarettes regularly; Polimanti, Kranzler & Gelernter, 2016). Further, the combination of PheWAS among affected
