Association of cognitive function and serum BDNF levels in euthymic bipolar disorder patients treated with rTMS

We hypothesized that rTMS could improve the cognitive function and increase the serum BDNF levels in the active group as compared to the sham group. We also examined the correlation between serum BDNF levels and cognitive function.The document included general data from the subjects, Hamilton Depression Rating Scale (HDRS), the Young Mania Rating Scale (YMRS), the MATRICS Consensus Cognitive Battery (MCCB), and the brain-derived neurotrophic factor (BDNF).
T test and χ2-squared test were performed to investigate demographic, baseline clinical variables and 2-weeks follow-up clinical variables between the rTMS group and the control group. Repeated measures ANOVA (RMANOVA) was used to test the significance of cognitive tests and serum BDNF levels. Pearson correlation analyses were performed to examine the relationship of serum levels of BDNF and cognitive variables, HDRS and YMRS scores. The threshold for significance was set at p<0.05. All statistical analyses were conducted using SPSS 21.0.

These findings indicated that rTMS could improve working memory and reasoning and problem solving in patients with BD. Moreover, the cognitive benefits may be positively associated with the changes of BDNF levels in euthymic BD patients after rTMS.

本研究假设，相较于假刺激组，重复经颅磁刺激（repetitive Transcranial Magnetic Stimulation，rTMS）可改善活跃治疗组受试者的认知功能，并升高其血清脑源性神经营养因子（brain-derived neurotrophic factor，BDNF）水平。本研究同时探讨了血清BDNF水平与认知功能之间的相关性。本研究收集了受试者的一般资料、汉密尔顿抑郁量表（Hamilton Depression Rating Scale，HDRS）评分、杨氏躁狂评定量表（Young Mania Rating Scale，YMRS）评分、MATRICS共识认知成套测验（MATRICS Consensus Cognitive Battery，MCCB）结果以及血清BDNF水平数据。

采用t检验与卡方检验，比较重复经颅磁刺激组与对照组的人口学资料、基线临床变量及2周随访临床变量。采用重复测量方差分析（Repeated Measures ANOVA，RMANOVA）检验认知测验结果与血清BDNF水平的组间差异显著性。采用Pearson相关分析探讨血清BDNF水平与认知变量、HDRS及YMRS评分之间的关联。本研究设定显著性阈值为p<0.05。所有统计分析均采用SPSS 21.0软件完成。

本研究结果显示，重复经颅磁刺激可改善双相情感障碍（Bipolar Disorder，BD）患者的工作记忆、推理及问题解决能力。此外，在接受重复经颅磁刺激后的心境稳定双相情感障碍患者中，其认知获益可能与BDNF水平的变化呈正相关。