Investigation of DRD2 and HTR2A mRNA Expression in Two Therapeutic States of Antipsychotic Polypharmacy and Aripiprazole Monotherapy in the Peripheral Blood of Patients With Schizophrenia

Objectives: Schizophrenia is a severe psychiatric disorder that has profound effects on both individuals and the community. Notwithstanding the suggestion for treating schizophrenia with a minimum dose of drugs, antipsychotic polypharmacy increases the patient’s care costs and drug interactions. Aripiprazole reduces the metabolic side effects of antipsychotic polypharmacy treatment. DRD2 and HTR2A can serve as predictors for response to treatment in schizophrenic patients. The purpose of this survey was to measure the DRD2 and HTR2A genes expression in the peripheral blood samples using Real-Time Quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR). Methods: A total of 19 patients with a long history of schizophrenia who received at least two types of antipsychotics with daily doses of more than 500 mg of chlorpromazine were entered into the study. The response rates to the treatment based on scores in the Brief Psychiatric Rating Scale (BPRS) questionnaire and DRD2 and HTR2A expression were compared between antipsychotic polypharmacy status and 6 months after monotherapy with aripiprazole. Results: The levels of DRD2 expression decreased significantly after the intervention. The mean changes in HTR2A expression and the BPRS questionnaire and also the relationship between changes in DRD2 and HTR2A expression and changes in BPRS score after the intervention were not significant. Discussion: The conversion of the antipsychotic polypharmacy state to monotherapy with aripiprazole has been accompanied by a significant decrease in DRD2A expression. These genes can be used for evaluating the response rate of schizophrenia treatments in the future.