Research Paper: Determination of Changes in Blood Biomarker Levels in Antipsychotic Polypharmacy and Aripiprazole Monotherapy in Patients With Long-term Schizophrenia

Objectives: Schizophrenia is a chronic psychiatric disorder, which reduces the patient’s quality of life. Although a minimum dose of medications has been recommended for treating this disorder, antipsychotic polypharmacy has been used experimentally leading to an increase in drug interactions. Aripiprazole is associated with a lower risk of metabolic side effects and is recommended as a first-line treatment for schizophrenia. Biomarkers can serve as predictive of treatment response in patients with schizophrenia. The aim of this study was to compare the efficacy of antipsychotic medication polypharmacy with Aripiprazole monotherapy in patients with long-term schizophrenia, using blood biomarkers. Methods: Nineteen patients with long-term schizophrenia, who had received at least 2 types of antipsychotics with daily doses of more than 500 mg of Chlorpromazine, were included in the study. The response rates to the treatment based on the Brief Psychiatric Rating Scale (BPRS) score and the blood level of Interleukin 2 (IL-2), Interleukin 6 (IL-6), Interleukin-1 Receptor Antagonist (IL-1RA), and Brain-derived Neurotrophic Factor (BDNF) biomarkers were compared in antipsychotic polypharmacy and 6 months after monotherapy with Aripiprazole. Results: The mean concentrations of IL-6, IL-1RA, and IL-2 significantly decreased after the intervention. The mean changes in the BPRS scores and also the relationship between changes in blood biomarkers and BPRS scores after intervention were not significant. Discussion: The conversion of the antipsychotic polypharmacy state to monotherapy with Aripiprazole has been accompanied by a significant decrease in the serum levels of IL-2, IL-6, and IL-1RA. These biomarkers can be used for evaluating the response rate of schizophrenia treatments in the future.