negative correlation between serum s100b and leptin levels in schizophrenic patients during treatment with clozapine and risperidone: preliminary evidence

recently, extensive efforts have been made to understand the rate of energy expenditure and the weight gain associated with atypical antipsychotic treatment, including identification of markers of obesity risk. in recent years, leptin, an adipocyte hormone, has gained significant interest in psychiatric disorders. s100b has been considered as a surrogate marker for astrocyte-specific damage in neurologic disorders. also, s100b has been detected in adipose with concentration as high as nervous tissue as a second release source. in this study we evaluated the relationship between s100b and leptin in schizophrenic patients under treatment with clozapine and risperidone.this study included 19 patients meeting the dsm-iv-tr criteria for schizophrenia, having body mass index (bmi) of 16- 25 kg/m2 and suffering schizophrenia for more than 3 years and from this study. twenty five healthy controls were group matched for age and gender whose bmi was 16-25 kg/m2. serum s100b and leptin levels and positive and negative symptom scale (panss) were assessed at admission and after six weeks. during the study, s100b showed a strong and negative correlation with leptin (r = -0.5, p = 0.01). also, there were negative correlation between serum s100b level and panss negative subscale after 6 weeks of treatment (r  = -0.048, p = 0.8). positive correlation between leptin level and panss suggested a potential role for leptin which can mediate the link between antipsychotic induced weight gain and therapeutic response in schizophrenia.