Department of Psychiatry, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan; Center for Geriatrics and Gerontology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan; Non-Invasive Neuromodulation Consortium for Mental Disorders, Society of Psychophysiology, Taipei, Taiwan; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; Department of Emergency Medicine, Taoyuan Armed Forces General Hospital, Taoyuan, Taiwan; Department of Life Sciences, National Central University, Taoyuan, Taiwan.
J Affect Disord. 2025 Jan 15;369:1161-1167. doi: 10.1016/j.jad.2024.10.087. Epub 2024 Oct 22.
Compared to functional magnetic resonance imaging (fMRI), source localization of a scalp-recorded electroencephalogram (EEG) provides higher temporal resolution and frequency synchronization to better understand the potential neurophysiological origins of disrupted functional connectivity (FC) in major depressive disorder (MDD). The present study aimed to investigate EEG-sourced measures to examine the FC in drug-free patients with MDD.
Resting-state 32-channel EEG were recorded in 84 drug-free patients with MDD and 143 healthy controls, and the cortical source signals were estimated. Exact low-resolution brain electromagnetic tomography (eLORETA) was used to compute the intracortical activity from regions within the default mode network (DMN) and frontoparietal network (PFN). Lagged phase synchronization was used as a measure of functional connectivity.
Compared with control subjects, the MDD group showed greater within-DMN alpha 1 and 2 bands and within-FPN alpha 1, 2, and beta 3 bands. Furthermore, the MDD group showed hyperconnectivity between the DMN and the FPN in the alpha 1 and 2 bands. Finally, higher levels of anhedonia were associated with higher between-network DMN and FPN connectivity in the alpha-1 band.
Due to the inherent limitations of eLORETA with predefined seeds, we could not exclude connectivity between regions of interest (ROIs), which may be related to the activity from regions adjacent to the ROIs.
The present findings support the importance of phase-lagged functional dysconnectivity in the neurophysiological mechanisms underlying MDD. Exploring the potential of these patterns as surrogates for treatment responses may advance targeted interventions for depression.
与功能磁共振成像（fMRI）相比，头皮记录脑电图（EEG）的源定位提供了更高的时间分辨率和频率同步性，以更好地理解重度抑郁症（MDD）中功能连接（FC）中断的潜在神经生理起源。本研究旨在调查无药物治疗的 MDD 患者的 EEG 源测量以检查 FC。
在 84 名无药物治疗的 MDD 患者和 143 名健康对照者中记录静息状态 32 通道 EEG，并估计皮质源信号。精确低分辨率脑电磁断层扫描（eLORETA）用于计算默认模式网络（DMN）和额顶网络（PFN）内区域的皮质内活动。滞后相位同步用作功能连接的度量。
与对照组相比，MDD 组在 DMN 内的 alpha 1 和 2 波段以及 PFN 内的 alpha 1、2 和 beta 3 波段中显示出更大的内 DMN 活动。此外，MDD 组在 alpha 1 和 2 波段中显示出 DMN 和 PFN 之间的超连接。最后，快感缺失水平较高与 alpha-1 波段中网络间 DMN 和 PFN 连接性较高相关。
由于使用预定义种子的 eLORETA 的固有局限性，我们不能排除感兴趣区域（ROI）之间的连接性，这可能与 ROI 相邻区域的活动有关。
本研究结果支持相位滞后功能失连接在 MDD 神经生理机制中的重要性。探索这些模式作为治疗反应替代物的潜力可能会推进针对抑郁症的靶向干预。
