Impaired antioxidant defense at the onset of psychosis.

Previous studies found peripheral activities of antioxidant enzymes to be abnormal in schizophrenic patients. It is not understood whether this is integral to the disease process or a result of long-term treatment with neuroleptics. Red blood cell activities of three antioxidant enzymes--superoxide dismutase, glutathione peroxidase, and catalase--were therefore examined in 14 drug-naive, first episode patients with a diagnosis of schizophrenia or schizophreniform disorder and 10 normal subjects. The patients had an average duration of psychosis of 4.46 days (SD 2.5). Superoxide dismutase activity was significantly lower in patients than in normal controls, with no difference between the groups in activities of the other two enzymes. Lower superoxide dismutase activity was associated with deterioration of school functioning from childhood to early adolescence and a history of poorer school functioning during early adolescence. These findings indicate a compromised antioxidant defense at the onset of psychosis, and suggest that oxidative injury might contribute to adverse developmental events in the pathogenic cascade of schizophrenia.