State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China; School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing, 100049, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
Department of Neurology, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China; Anhui Province Key Laboratory of Cognition and Neuropsychiatric Disorders, Hefei, 230032, China; Collaborative Innovation Center of Neuropsychiatric Disorders and Mental Health, Hefei, 230032, China.
Brain Stimul. 2022 Jan-Feb;15(1):214-225. doi: 10.1016/j.brs.2021.12.008. Epub 2021 Dec 22.
Electroconvulsive therapy (ECT) is widely considered as an effective and fast-acting option for treating patients with major depressive disorder (MDD). However, the neural basis underlying this powerful therapy remains uncertain. Recent studies have suggested that the healthy brain may operate near a critical state, which may reflect a balance between neuronal excitation and inhibition.
In the present study, we investigated whether there are any changes regarding criticality in MDD and, if so, whether ECT can reverse them. Critical dynamics analyses were performed on resting-state functional magnetic resonance imaging (rs-fMRI) data collected from 39 MDD patients and 38 healthy controls (HCs).
We found that compared with HCs, MDD patients, especially those who responded positively to ECT, tended to have smaller average avalanch sizes and lower branching ratios, suggesting a sub-critical state, at both the whole-brain and functional network levels. Importantly, ECT effectively corrected such anomalies, accompanied by enhanced degree centrality and functional connectivity of high-degree nodes located in the networks including the default-mode and the frontoparietal networks.
These results indicate that ECT can modulate large-scale brain dynamics of MDD patients to be closer to criticality. Our study sheds new light on the pathology of MDD and the network mechanism by which ECT influences treatment.
电休克疗法（ECT）被广泛认为是治疗重度抑郁症（MDD）患者的有效且起效迅速的选择。然而，这种强大疗法的神经基础仍不确定。最近的研究表明，健康的大脑可能处于临界状态，这可能反映了神经元兴奋和抑制之间的平衡。
在本研究中，我们调查了 MDD 是否存在临界性变化，如果存在，ECT 是否可以逆转这些变化。对从 39 名 MDD 患者和 38 名健康对照者（HCs）收集的静息态功能磁共振成像（rs-fMRI）数据进行了临界动力学分析。
我们发现，与 HCs 相比，MDD 患者，尤其是那些对 ECT 反应良好的患者，在全脑和功能网络水平上，平均雪崩大小和分支比均较小，表明处于亚临界状态。重要的是，ECT 有效地纠正了这些异常，同时增强了位于默认模式和额顶叶网络等网络中高节点的度中心性和功能连接性。
这些结果表明，ECT 可以调节 MDD 患者的大脑大范围动力学，使其更接近临界状态。我们的研究为 MDD 的病理学和 ECT 影响治疗的网络机制提供了新的视角。
