In the present study, the possible associations of the polymorphisms c.957C > T (rs6277) and c.-585A > G (rs1799978) of the DRD2 gene with the emotional/behavior problem section of the CBCL/6–18 were investigated; a significant association was detected between the polymorphism c.957C > T (rs6277) and the occurrence of oppositional defiant disorders, attention problems, and hyperactivity. Here, DRD2 is linked to Oppositional defiant disorder.