The Relationships Between Brain-derived Neurotrophic Factor, Cognition And Clinical Status In Patients With Schizophrenia

Objective:Our study attempted to examine the serum brain-derived neurophic factor(BDNF) concentrations and cognitive functions in schizophrenic patients and their changes after treatment.It also explored the relationships between serum BDNF, cognition and the clinical status in patients with schizophrenia.Methods:Totally 111 patients with schizophrenia who were successively admitted into the psychiatric hospital were enrolled into the study.The serum BDNF concentrations were assessed at baseline in these patients and were compared with healthy controls(control group 1).Eligible patients entered into the 4-week treatment study and the serum BDNF,the Wisconsin Card Sorting Test(WCST),the Personal and Social Performance Scale(PSP),the Positive And Negative Syndrome Scale (PANSS) and the Clinical Global Impression(CGI) were assessed before and after treatment.For the WCST comparison,another normal sample(control group 2) was enrolled and WCST was assessed.Antipsychotic medications and their dosage were chose by treating pshysicians.A well-trained researcher blind to the treatments evaluated the rating scales and cognitive measures.The serum BDN concentrations were measured by enzyme linked immunosorbent assay(ELISA).All the data were analyzed with t test,rank sum test, correlation analysis and analysis of variance(ANOVA).The significance level was set at 0.05.Results:1.The serum BDNF levels was significantly lower in patients with schizophrenia compared to normal controls(20.67±5.78ng/ml vs.23.72±5.61ng/ml,t=4.310, p＜0.01).2.The serum BNDF levels were significantly increased in schizophrenic patients after 4-week treatment(22.51±6.05,t=-2.027,p=0.046),close to normal level.3.The patients had significantly poor performance in the numbers of categories, correct responses,perseverative errors and non-perseverative errors of WCST compared with healthy controls(p＜0.01).4.The mean PSP score in patients with schizophrenia was 46.05 at baseline, indicating a remarkable impairments in social cognition,and was significantly increased to 71.95 after treatment(t=12.733,p＜0.01).5.Correlation analysis revealed no association between the increase levels of BDNF and improvement in cognition and symptoms of schizophrenia patients.Conclusion:1.The serum BDNF is downregulated in schizophrenia patients compared to healthy controls and is significantly increased after 4-week antipsychotic treatment.The results support the view that BDNF might have an important role in schizophrenia.2.Schizophrenic patients demonstrate impairments in neural and social cognition, which could be improved with short-term treatment of antipsychotics.3.The parallel improvement of cognitive functions to the BDNF increase after treatment suggest that antipsychotic medication may upgrlate BDNF functioning.