Antioxidant Status in Paranoid Schizophrenia and Alzheimer’s Disease

Objective. To study measures of the plasma antioxidant profile in patients with paranoid schizophrenia and Alzheimer’s disease (AD). Materials and methods. The study included 33 patients with paranoid schizophrenia and 18 patients with AD. Groups of patients with treatment-resistant schizophrenia and responding positively to treatment were identified. Measures of the antioxidant profile were determined by chemiluminometry and spectrofluorimetry. Results and discussion. Systemic oxidative stress due to lack of plasma low molecular weight antioxidants was not seen in AD though “thiol” protein oxidative stress was detected, providing indirect evidence of insufficiency of the glutathione system. Systemic oxidative stress was also not typical of patients with treatment-resistant paranoid schizophrenia while “thiol” oxidative stress was marked. Patients with paranoid schizophrenia and responding to therapy showed the opposite picture – systemic oxidative stress was more intense and “thiol” oxidative stress was less so. Of the neuroleptics studied, haloperidol, zuclopenthixol, risperidone, and ziprasidone had no antioxidant properties, while pericyazine, clozapine, and especially chlorpromazine had marked antioxidant properties, though they were unlikely have effects on plasma antioxidant potential. These results led to the conclusion that the glutathione component of the antioxidant system is most impaired in treatment-resistant paranoid schizophrenia and AD, while systemic antioxidant stress is minor. Oxidative impairments were less pronounced in successfully treated paranoid schizophrenia.