Schizoaffective disorder is a disease with both affective and psychotic symptoms. In this study, we aimed to compare oxidative metabolism markers of schizoaffective disorder, bipolar disorder and schizophrenic patients. Furthermore, we also aimed to investigate whether schizoaffective disorder could be differentiated from schizophrenia and bipolar disorder in terms of oxidative metabolism.

Total oxidant status (TOS) and total antioxidant status (TAS) were measured in the blood samples that were collected from schizoaffective patients (n = 30), bipolar disorder patients (n = 30) and schizophrenic patients (n = 30). Oxidative stress index (OSI) was calculated by dividing TOS by TAS.

TOS and OSI were found to be higher in patients with schizoaffective disorder compared with those in schizophrenia and bipolar disorder patients. TAS was not significantly different between the groups.

Schizoaffective disorder was found to be different from bipolar disorder and schizophrenia in terms of oxidative parameters. This result may indicate that schizoaffective disorder could differ from bipolar disorder and schizophrenia in terms of biochemical parameters. Increased TOS levels observed in schizoaffective disorder may suggest poor clinical course and may be an indicator of poor prognosis.