Background

Previous studies have suggested that individuals with generalized anxiety disorder (GAD) would show inefficient whole-brain communication and dysconnectivity in the fronto-parietal-subcortical sub-networks in the white matter (WM) structural network. However, these hypotheses have yet to be tested.

Methods

Individual WM structural networks were constructed based on diffusion MRI data and deterministic tractography in 34 first-episode, medication-naïve adolescents with GAD and 27 healthy controls (HCs). Graph theory was applied to investigate the topological organization alterations of the structural network.

Results

GAD patients showed disrupted small-world configurations (i.e., increased path length and decreased clustering coefficient) and hub organization (i.e., less connection strength in the feeder and local connections). A decreased connection strength was found in a GAD-related sub-network (mainly involving the frontal-subcortical circuits), which was able to distinguish GAD patients from HCs with higher accuracy (area under the curve of 0.96, sensitivity of 94%, specificity of 89%) than clinical scores and other topological alternations.

Limitations

The current study just compared GAD patients with HCs based on a small sample, leaving whether the alternations found here are specific to GAD still an open question. Future studies are recommended to recruit patients with other anxiety disorders (e.g., social anxiety disorder) and/or comorbid mood disorders to identify the GAD-specific WM alterations using a larger sample.

Conclusions

Our findings highlight the disruption of the topological organization of the whole-brain WM structural network (especially the frontal-subcortical circuits) in GAD, and suggest the potential of using structural connectivity of the GAD-related sub-network as a biomarker for GAD patients.

中文翻译：

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初发，未曾使用过药物的青少年患有广泛性焦虑症的白质结构网络障碍。

背景

先前的研究表明，患有广泛性焦虑症（GAD）的人在白质（WM）结构网络的额顶叶下皮层子网络中将显示低效的全脑沟通和不连通。但是，这些假设尚待检验。

方法

基于扩散MRI数据和确定性束线图，在34名具有GAD的首次发作，未接受药物治疗的青少年和27名健康对照（HCs）中构建了单独的WM结构网络。应用图论研究结构网络的拓扑组织变化。

结果

GAD患者显示出小世界配置受到干扰（即，路径长度增加和聚类系数降低）和集线器组织（即，馈线和本地连接中的连接强度降低）。在与GAD相关的子网（主要涉及额下皮层回路）中发现连接强度降低，从而能够以较高的准确度（曲线下面积为0.96，灵敏度为94％，特异性）区分GAD患者和HCs。占89％），而不是临床评分和其他拓扑变化。

局限性

当前的研究只是根据少量样本比较了GAD患者和HCs，因此这里发现的替代是否特定于GAD仍然是一个未解决的问题。建议进行进一步的研究以招募患有其他焦虑症（例如社交焦虑症）和/或合并症的情绪障碍患者，以使用更大的样本来识别GAD特异性WM改变。

结论

我们的发现突出显示了GAD中全脑WM结构网络（尤其是额下皮层回路）的拓扑结构的破坏，并暗示了将GAD相关子网络的结构连通性用作GAD患者生物标志物的潜力。