Tardive dyskinesia (TD) is a motor adverse effect of chronic antipsychotic medication. It has been suggested to involve dopamine neurotransmission system changes. AKT1 acts downstream of the D(2) receptor that is blocked by all antipsychotics to some degree. The AKT1 gene has not been investigated in TD. We examined eight polymorphisms spanning the AKT1 gene and their association with TD in our schizophrenia sample of 193 Caucasians, 76 of which with TD. AKT1 polymorphisms and haplotypes were not significantly associated with TD. However, we detected a significant interaction between rs6275 of DRD2 and rs3730358 of AKT1 (p<1 x 10(-5)).