Schizophrenia is a major mental disorder that have a multifactorial ethiology, but genetic and hyperactivity of dopamine receptors also have an important role.Free radicals such as super oxide, nitric oxide cause cell injury when they are generated in excess or when the antioxidant defenses are impaired. Both of these processes seem to be affect schizophrenia. This study was designed to determine a correlation between schizophrenia and stress oxidative factors.

This study was carried out 60 schizophrenic patients and 180 normal subjects as a control group based on DSM-IV-T.R. criteria. The two groups were paired match based on age, sex, and counfunder factors such as smoking.

For determination of stress oxidative indexes we used three methods such as Saths (for lipid peroxidation) Hu (for thiol groups) and FRAP (for antioxidant capacity).Analysis was done by statistical tests, also correlation severity by odds ratio analysis.

The mean value of thiol groups in schizophrenic group was significantly lower than control group (P=0.0001),and also the mean value of FRAP(Ferric Reducing Ability of Plasma) index was significantly lower than control group (P=0.0001),but the mean value of TBA was more than control group with P= 0.103 was not significant .

There was significantly negative correlation between schizophrenia and thiol groups. This data revealed that antioxidant defense mechanisms might be impaired in schizophrenia,these findings also provided theoretical bases for the development of new strategy in the treatment of schizophrenia, such as antioxidant supplement.