The interaction between superoxide dismutase and prolactin is involved in response to haloperidol and risperidone treatment in schizophrenia: a double-blind and randomized study.

Objective The aim of this study was to investigate the inter-relationships among prolactin(PRL),superoxide dismutase(SOD)and symptoms in schizophrenia during treatment with typical and atypical antipsychotics.Methods Seventy-eight inpatients with schizophrenia were randomly assigned to 12-week treatment with 20 mg/day of haloperidol or 6 mg/day of risperidone using a double-blind design. Clinical efficacy was assessed with the Positive and Negative Syndrome Scale.Blood SOD and serum PRL levels were assayed with radioimmunometric assay before and after treatment,and compared to 30 sex-and age-matched normal subjects.Results SOD levels were significantly elevated,but PRL levels were significantly decreased in patients at baseline in comparison with controls(both P<0.05).There was negative relationship between SOD and PRL levels in schizophrenia patients at baseline(P<0.05).Blood SOD decreased and PRL level increased after treatment in both haloperidol and risperidone group(both P< 0.01).There were no significant differences in SOD and PRL levels both at baseline and after treatment between haloperidol and risperidone groups(all P>0.05).The improvement of negative symptoms was related to the change in SOD levels before and after treatment(P<0.05),and the improvement of positive symptoms to the change in PRL(P<0.01).Conclusions These findings suggest that the dysregulation of the neuroendocrine system and antioxidant enzyme interactions may exist in schizophrenia,which may be implicated in the responses to antipsychotic treatments.