DRD2 and schizophrenia: The present exploratory study has investigated four SNPs in the DRD2/ANKK1 locus (rs6275, rs6277, rs2242592 and rs1800497) and two SNPs in the COMT gene (rs4680 and rs165599) in order to analyze their association with attention and executive function, in patients with schizophrenia as compared to healthy volunteers.