There were no significant associations observed for <i>DRD2</i> rs1076560 SNP, <i>OPRM1</i> rs1799971 SNP, and combined genotypes of both SNPs in the SUD group.
Compared to controls, ADHD patients (with and without SUDs) showed significantly increased frequency of the DBH (rs2519152: OR 1.73; CI 1.15-2.59; P=0.008) and the OPRM1 risk genotypes (rs1799971: OR 1.71; CI 1.17-2.50; P=0.006).