Many of the reported common variant SNP or haplotype relative risks were exceptionally large: often >1.5 and >2 for DRD3, HTR2A, MTHFR, NRG1, and PRODH. Rigorous control for multiple testing of genetic markers, haplotypes, and/or phenotypes was evident in one study (ZDHHC8). None of the P-values in the primary studies were genome-wide significant 15 (P<5x10−8), and most were not notable after correction for the number of SNPs genotyped.
