National Clinical Research Center for Mental Disorders, and Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, China.
National Clinical Research Center for Mental Disorders, and Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, China.
J Psychiatr Res. 2021 Dec;144:234-240. doi: 10.1016/j.jpsychires.2021.10.016. Epub 2021 Oct 21.
The severity of major depressive disorder (MDD) can be aggravated by gastrointestinal (GI) symptoms, but the neuroimaging mechanism underlying GI symptoms still remains unclear. In this study, we recruited 52 medication-free and first-episode MDD patients (35 with GI symptoms and 17 without GI symptoms) and 28 age-, sex-, and education-matched healthy controls to explore the inter-group differences in neuroimaging findings. All the participants underwent resting-state functional magnetic resonance imaging (fMRI) scan, and the functional connectivities that were reported to be abnormal in MDD were our focus of exploration. Voxel-mirrored homotopic connectivity (VMHC) method was used to explore the interhemispheric homotopic functional connectivity of all the subjects. Patients with MDD showed significantly different VMHC in brain regions in the default mode network (DMN), including the middle frontal gyrus, precuneus, inferior parietal lobule, and posterior cingulate cortex. Patients with GI symptoms exhibited significantly decreased interhemispheric homotopic functional connectivity in the middle frontal gyrus and superior frontal gyrus, compared with patients without GI symptoms. These results suggested that the DMN is involved in the neuropathology of MDD. Interhemispheric homotopic connectivity in specific regions could be applied as a biomarker to distinguish MDD patients with GI symptoms from those without GI symptoms.
重度抑郁症（MDD）的严重程度可能会因胃肠道（GI）症状而加重，但胃肠道症状的神经影像学机制仍不清楚。在这项研究中，我们招募了 52 名未服用药物且首次发作的 MDD 患者（35 名有胃肠道症状，17 名无胃肠道症状）和 28 名年龄、性别和教育程度相匹配的健康对照者，以探讨影像学组间差异。所有参与者均接受静息态功能磁共振成像（fMRI）扫描，我们重点探讨了报道中与 MDD 异常相关的功能连接。使用镜像同伦连接（VMHC）方法来探索所有被试者大脑半球间的同伦功能连接。MDD 患者在默认模式网络（DMN）的脑区中显示出明显不同的 VMHC，包括额中回、楔前叶、顶下小叶和后扣带回皮质。与无胃肠道症状的 MDD 患者相比，有胃肠道症状的 MDD 患者在额中回和额上回的大脑半球间同伦功能连接明显减少。这些结果表明，DMN 参与了 MDD 的神经病理学。特定区域的大脑半球间同伦连接可作为一种生物标志物，将有胃肠道症状的 MDD 患者与无胃肠道症状的 MDD 患者区分开来。
