低场强磁刺激抗抑郁作用的神经影像机制研究

The delayed effect onset and adverse effects are significant clinical problems in the treatment of major depressive disorder (MDD). Clinical studies demonstrate that low field magnetic stimulation (LFMS) has rapid mood-enhancing effects in the treatment of MDD. The rapid antidepressant characteristics of LFMS have attracted more and more attention. Our previous studies have also confirmed the antidepressant effect of LFMS for refractory depression. However, the neuroimaging mechanism of this technique is not clear. It has been found that the structure and function of limbic system-cortex-striatum-globus pallidus-thalamus (LCSPT) are abnormal in MDD patients, and the existing antidepressants and transcranial magnetic stimulation has therapeutic effect by regulating LCSPT neural circuit. Therefore, this project focuses on the changes of LCSPT neural circuit. We will conduct case-control study to explore the association of depressive symptoms with resting-state brain activity and functional connections, and we will also carry out the randomized, double-blind, sham controlled study of LFMS in the treatment of depressed patients. All patients will have resting-state fMRI test before and after LFMS or sham treatment. By comparing the differences of brain activation and functional connection before and after LFMS with sham stimulation as reference, we aims to explore the brain network regulation mechanism of its antidepressant effect. This project has not only clinical importance, but also scientific significance.

当前抗抑郁治疗面临起效滞后、不良反应等问题，而低场强磁刺激（LFMS）具有快速抗抑郁特点越来越受到关注，我们前期研究也证实了LFMS在难治性抑郁中的抗抑郁作用，然而该技术的神经影像机制尚不清楚。研究发现抑郁症患者存在边缘系统-皮层-纹状体-苍白球-丘脑（limbic-cortical-striatal-pallidal-thalamic, LCSPT）神经环路的结构和功能异常，而现有的抗抑郁药物和经颅磁刺激治疗可通过调节LCSPT环路发挥治疗作用。因此，本项目重点关注LFMS对LCSPT神经环路的影响，通过病例对照研究首先明确静息状态脑区活动及功能连接与抑郁症状的关系，并通过开展LFMS抗抑郁的随机双盲伪刺激对照临床研究，治疗前后采集静息态fMRI数据，对比分析LFMS和伪刺激干预前后的静息态脑区活动与功能连接的差异，探索其抗抑郁作用的脑网络调节机制。本项目具有重要的临床意义和科学意义。

抑郁症的神经影像机制是当前研究的热点，影像学研究表明，抗抑郁治疗可对抑郁症患者的异常的脑区活动及脑功能连接产生影响。本项目开展了抑郁症的静息态功能影像研究，发现部分脑区功能连接异常可能与抑郁易感性相关，通过LFMS抗抑郁的临床研究，对比分析治疗前后的静息态脑功能影像的差异，发现默认网络（DMN）子网络内功能连接的异常可能预测抗抑郁疗效。本研究揭示了抑郁症的病理生理机制及抗抑郁治疗的脑网络调节机制，具有重要的临床意义和科学意义。