Objective: We aimed to evaluate the role of oxidative stress in individuals with schizoaffective disorder. In this context, serum total antioxidant level (TAS), total oxidant level (TOS), and peroxiredoxin-1 (PRDX1) levels were measured in patients; The findings were compared with those of a healthy control group and their relationship with clinical variables was examined, with the aim of contributing to the understanding of oxidative stress mechanisms in the pathogenesis of the disorder.

Materials and Methods: The study included 80 participants, consisting of 40 patients diagnosed with schizoaffective disorder and 40 healthy controls. The patients were evaluated using the Clinical Global Impression Scale, the Positive and Negative Syndrome Scale, the Hamilton Depression Rating Scale, and the Young Mania Rating Scale. TOS and TAS were determined by automatic measurement, while serum peroxiredoxin levels were measured using the ELISA method; OSI was calculated using the TOS/TAS ratio.

Results: When comparing the TAS, TOS, OSI, and PRDX1 levels between patients with schizoaffective disorder and the control group, no significant difference was found in TAS levels (p=0.088). However, the patient group had significantly higher TOS and OSI levels (p=0.002 and p=0.001, respectively) and significantly lower PRDX1 levels (p=0.001). No significant correlations were observed between continuous clinical characteristics and TAS, TOS, PRDX1, or OSI levels. Additionally, no significant correlation was observed between PRDX1 levels and TAS or TOS levels (r=0.123, p=0.443 and r=-0.145, p=0.372, respectively).

Conclusion: Our findings support increased oxidative stress and decreased PRDX1 levels in patients with schizoaffective disorder, and show no significant relationship between TAS and PRDX1; this indicates the role of PRDX1 in the oxidative stress response in patients.