To determine whether mQTL variants associated with the top-ranked DMPs (for both ADHD and the ADHD PRS) were also implicated in GWAS for ADHD (i.e., pleiotropic for methylation and ADHD), we examined the results from the PGC ADHD GWAS meta-analysis3 in the regions of SLC7A8, MARK2, GART, SON, USP31, and LOC100130015 (Table 2 and Table S7). Here, USP31 is linked to attention deficit-hyperactivity disorder.