SOD1 and schizophrenia: The level of MDA, an indicator of oxidative stress and an end product of lipid peroxidation, measured as thiobarbituric acid-reactive substance (TBARS), was significantly (P < 0.001) higher in schizophrenics, indicating increase in level of oxidative stress due to schizophrenia.[9] The SOD and GSHPx activities in red cells, which act as sinks for O2.- and H2 O2 produced in plasma, decreased significantly (P < 0.001) in schizophrenics as compared to controls [Table 2].