Second Xiangya Hospital, National Clinical Research Center for Mental Disorders, and Department of Psychiatry, Changsha, Hunan, China.
Robarts Research Institution, University of Western Ontario, London, Ontario, Canada.
Cereb Cortex. 2022 Jul 21;32(15):3127-3136. doi: 10.1093/cercor/bhab405.
The default mode network (DMN) is related to brain functions and its abnormalities were associated with mental disorders' pathophysiology. To further understand the common and distinct DMN alterations across disorders, we capitalized on the probability tracing method and graph theory to analyze the role of DMN across three major mental disorders. A total of 399 participants (156 schizophrenia [SCZ], 90 bipolar disorder [BP], 58 major depression disorder [MDD], and 95 healthy controls [HC]) completed magnetic resonance imaging (MRI)-scanning, clinical, and cognitive assessment. The MRI preprocessing of diffusion-tensor-imaging was conducted in FMRIB Software Library and probabilistic fiber tracking was applied by PANDA. This study had three main findings. First, patient groups showed significantly lower cluster coefficient in whole-brain compared with HC. SCZ showed significantly longer characteristic path compared with HC. Second, patient groups showed inter-group specificity in abnormalities of DMN connections. Third, SCZ was sensitive to left_medial_superior_frontal_gyrus (L_SFGmed)-right_anterior_cingulate_gyrus (R_ACG) connection relating to positive symptoms; left_ACG-right_ACG connection was the mania's antagonistic factor in BP. This trans-diagnostic study found disorder-specific structural abnormalities in the fiber connection of R_SFGmed-L_SFGmed-R_ACG_L_ACG within DMN, where SCZ showed more disconnections compared with other disorders. And these connections are diagnosis-specifically correlated to phenotypes. The current study may provide further evidence of shared and distinct endo-phenotypes across psychopathology.
默认模式网络（DMN）与大脑功能有关，其异常与精神障碍的病理生理学有关。为了进一步了解跨障碍的 DMN 改变的共同和独特之处，我们利用概率追踪方法和图论分析了 DMN 在三种主要精神障碍中的作用。共有 399 名参与者（156 名精神分裂症 [SCZ]、90 名双相情感障碍 [BP]、58 名重度抑郁症 [MDD]和 95 名健康对照组 [HC]）完成了磁共振成像（MRI）扫描、临床和认知评估。弥散张量成像的 MRI 预处理在 FMRIB 软件库中进行，概率纤维跟踪由 PANDA 应用。本研究有三个主要发现。首先，与 HC 相比，患者组全脑的簇系数显著降低。与 HC 相比，SCZ 的特征路径明显更长。其次，患者组在 DMN 连接的异常方面表现出组间特异性。第三，SCZ 对与阳性症状相关的左额上回（L_SFGmed）-右前扣带回（R_ACG）连接敏感；BP 中的躁狂拮抗因素是左前扣带回-右前扣带回的连接。这项跨诊断研究发现，DMN 内 R_SFGmed-L_SFGmed-R_ACG_L_ACG 的纤维连接存在特定于障碍的结构异常，与其他障碍相比，SCZ 显示出更多的连接中断。并且这些连接与表型具有诊断特异性相关。本研究可能为精神病理学中的共享和独特内表型提供进一步的证据。
