We performed polygenic risk score (PRS) analysis in order to evaluate the consistency between the deCODE and the iPSYCH CUD phenotypes. When using the iPSYCH cohort as discovery, we observed a significant association of CUD PRS in the deCODE cohort with CUD (e.g P-value=2.17x10−9; P-value threshold <0.01 in the discovery GWAS) but not with schizophrenia or bipolar disorder (Supplementary Table 4), supporting that the associations in the iPSYCH cohort primarily are driven by CUD and not the comorbid psychiatric disorders.
