Multi-factorial Etiology of Bipolar Disorder and Schizophrenia in Iran: No Evidence of Borna Disease Virus Genome

ABSTRACT &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Background and Objectives: Psychiatric disorders such as schizophrenia and bipolar disorder pose a high burden among the general population. Etiological factor(s) of such disorders remain unknown. Borna disease virus (BDV) is a neurotropic virus that has been suggested as an etiological agent for psychiatric disorders. Therefore, we aimed to investigate the prevalence of BDV among patients with schizophrenia and bipolar disorder. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Methods: Peripheral blood mononuclear cells (PBMCs) of schizophrenic (n=75) and bipolar (n=55) patients and healthy blood donors (n=125) were extracted form whole blood samples. RNA was extracted from PBMCs and the presence of BDV P40 RNA was assessed by reverse transcription-polymerase chain reaction. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Results: The BDV genome was not detected in any of the subjects. Positive family history of disease was significantly more frequent among patients (P=0.0001). There was a significant association between contact with animals and psychiatric illnesses (P<0.05). Moreover, education level differed significantly between the two groups (P<0.05). &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Conclusion: The results indicate no evidence of BDV genome among patients with psychiatric disorders. Serological examination for BDV antigens or antibodies could provide further information in this regard. In addition, contact with cats is significantly more prevalent among patients with mental illnesses, which might be due to infection with Toxoplasma gondii. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Keywords: Borna disease virus, Psychiatric disorder, Schizophrenia, Bipolar disorder, Risk factors.