功能专业化是人类大脑的特征,用于了解重度抑郁症(MDD)的病理生理学。人类专业化的程度是指半球内部和跨半球的相互作用。然而,以前的大多数研究只关注MDD的半球间连通性,结果因研究而异。因此,MDD中的脑功能连接不对称应进一步研究。
REST-meta-MDD项目提供了753例MDD患者和451例健康对照的静息状态fMRI数据。25个项目捐助者使用数据处理助理国家功能磁共振成像软件在当地对数据进行了预处理,并共享了最终索引。不对称参数(PAS),一种新的基于体素的全脑定量测量,反映了半球间和半球内的不对称性,已报告。我们还研究了年龄的影响,性别和临床变量(包括症状严重程度,疾病持续时间和三种抑郁表型)。
与健康对照相比,MDD患者在默认模式网络的大多数区域显示PAS评分增加(半球专业化减少),控制网络,注意网络以及小脑和视觉皮层中的一些区域。人口统计学特征和临床变量对这些异常有重大影响。
虽然大样本量可以提高统计能力,需要未来的独立努力来确认我们的结果。
我们的研究结果突出表明,许多大脑网络有助于MDD的广泛临床病理生理学,并表明一个横向的,在MDD中,高效和经济的大脑信息处理系统被破坏。这些发现可能有助于从新的半球专业化角度全面阐明MDD的病理生理学。
Functional specialization is a feature of human brain for understanding the pathophysiology of major depressive disorder (MDD). The degree of human specialization refers to within and cross hemispheric interactions. However, most previous studies only focused on interhemispheric connectivity in MDD, and the results varied across studies. Hence, brain functional connectivity asymmetry in MDD should be further studied.
Resting-state fMRI data of 753 patients with MDD and 451 healthy controls were provided by REST-meta-MDD Project. Twenty-five project contributors preprocessed their data locally with the Data Processing Assistant State fMRI software and shared final indices. The parameter of asymmetry (PAS), a novel voxel-based whole-brain quantitative measure that reflects inter- and intrahemispheric asymmetry, was reported. We also examined the effects of age, sex and clinical variables (including symptom severity, illness duration and three depressive phenotypes).
Compared with healthy controls, patients with MDD showed increased PAS scores (decreased hemispheric specialization) in most of the areas of default mode network, control network, attention network and some regions in the cerebellum and visual cortex. Demographic characteristics and clinical variables have significant effects on these abnormalities.
Although a large sample size could improve statistical power, future independent efforts are needed to confirm our results.
Our results highlight the idea that many brain networks contribute to broad clinical pathophysiology of MDD, and indicate that a lateralized, efficient and economical brain information processing system is disrupted in MDD. These findings may help comprehensively clarify the pathophysiology of MDD in a new hemispheric specialization perspective.