National-Local Joint Engineering Research Center of Rehabilitation Medicine Technology, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, China; Rehabilitation Industry Institute, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, China.
College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, China.
Neuroimage Clin. 2024;42:103594. doi: 10.1016/j.nicl.2024.103594. Epub 2024 Mar 18.
Hierarchy is the organizing principle of human brain network. How network hierarchy changes in subthreshold depression (StD) is unclear. The aim of this study was to investigate the altered brain network hierarchy and its clinical significance in patients with StD.
A total of 43 patients with StD and 43 healthy controls matched for age, gender and years of education participated in this study. Alterations in the hierarchy of StD brain networks were depicted by connectome gradient analysis. We assessed changes in network hierarchy by comparing gradient scores in each network in patients with StD and healthy controls. The study compared different brain subdivisions if there was a different network. Finally, we analysed the relationship between the altered gradient scores and clinical characteristics.
Patients with StD had contracted network hierarchy and suppressed cortical range gradients. In the principal gradient, the gradient scores of default mode network were significantly reduced in patients with StD compared to controls. In the default network, the subdivisions of reduced gradient scores were mainly located in the precuneus, superior temporal gyrus, and anterior and posterior cingulate gyrus. Reduced gradient scores in the default mode network, the anterior and posterior cingulate gyrus were correlated with severity of depression.
The network hierarchy of the StD changed and was significantly correlated with depressive symptoms and severity. These results provided new insights into further understanding of the neural mechanisms of StD.
层级组织是人类大脑网络的组织原则。阈下抑郁（StD）患者的网络层级如何变化尚不清楚。本研究旨在探讨 StD 患者脑网络层级改变及其临床意义。
共纳入 43 例 StD 患者和 43 例年龄、性别和受教育年限相匹配的健康对照者。采用连接组梯度分析描绘 StD 脑网络的层级改变。通过比较 StD 患者和健康对照者各网络的梯度得分，评估网络层级的改变。如果存在不同的网络，则比较不同的脑区。最后，分析了改变的梯度得分与临床特征之间的关系。
StD 患者的网络层级收缩，皮质范围梯度受到抑制。在主梯度中，与对照组相比，StD 患者的默认模式网络的梯度得分显著降低。在默认网络中，梯度得分降低的脑区主要位于楔前叶、颞上回以及扣带回的前后部。默认网络、扣带回前后部的梯度得分降低与抑郁严重程度相关。
StD 的网络层级发生改变，并与抑郁症状和严重程度显著相关。这些结果为进一步理解 StD 的神经机制提供了新的见解。
