Assessment of Effects of the OPRD1 and OPRM1 Genes Encoding Opioid Receptors on Apathy in Schizophrenia

Abstract

Because of the involvement in motivational processes, opioid receptors are potential targets for apathy treatment in schizophrenia. We therefore searched for associations between the opioid receptor gene polymorphisms (OPRM1 (rs1799971) and OPRD1 (rs1042114, rs533123)) and apathy measured with the Apathy Evaluation Scale-S in a group of 284 schizophrenia patients. We analyzed individual genotypes, haplotypes, and the digenic interaction and observed nominally significant associations of rs1042114 genotypes and the rs1042114*rs1799971 interaction with behavioral apathy scores. The associations, however, did not withstand correction for multiple comparisons. Thus, the results did not provide enough evidence for the opioid receptor gene effects on apathy in schizophrenia patients.