Polygenic risk scores (PRS) of related traits in discovery datasets can be used to test the polygenic effect between those traits and the study trait in the target sample. To our knowledge, there have been few large-cohort GWAS on psychiatric diseases done in East Asian populations. The CONVERGE (China, Oxford and Virginia Commonwealth University Experimental Research on Genetic Epidemiology) consortium performed the largest GWAS so far for major depressive disorder (MDD) in more than 10,000 Chinese women (Converge_Consortium, 2015). We obtained the relevant summary statistics from this study from the Psychiatric Genomics Consortium (PGC) website (http://www.med.unc.edu/pgc/results-and-downloads). Common SNPs between CONVERGE and our Thai sample were selected for downstream analysis. The summary data of the common SNPs were clumped by LD with r2 < 0.2, using a 200 kb window. As described previously (International Schizophrenia et al., 2009), MDD PRS was calculated as the sum of the risk alleles with P values less than a threshold (PT), weighted by the effect sizes. The associations between the constructed MDD PRS and alcohol-related phenotypes in our Thai cohorts were tested by linear (AD
