中文摘要：

对周围的情境有正常的认知及产生相应的情绪对于人类社会交往有重要意义.与健康人群相比,抑郁个体却对情境有着减弱的认知加工及过强的情绪加工,这反映了大脑中认知及情绪网络功能上存在异常.以脑功能磁共振成像为研究手段,近年来对抑郁症脑机制的研究逐渐增多.这些研究在认知、情绪以及二者交互作用3个方面集中显示了额叶-边缘系统的功能改变.其中,情绪网络异常主要体现在杏仁核和脑岛,并涉及5-羟色胺转运体基因型与抑郁症之间的关系;认知网络异常主要体现在执行控制和默认网络;而抑郁症对二者交互作用的影响则主要体现在杏仁核和背外侧前额叶.了解归纳与抑郁症相关的认知和情绪脑网络异常能够为将来进一步揭示抑郁症发生的神经机制奠定基础,同时为更加深入的研究提供线索.

英文摘要：

It is essential for social interactions if one can process the perceived external world with appropriate cognitive control and well-regulated emotion. However, compared with healthy individuals, patients with major depression disorder （MDD） usually exhibit compromised cognitive and enhanced emotional processes, respectively; and these behavioral changes have been shown to be associated with alterations in functional brain networks. Recent advances of MDD research have been increasingly involving functional magnetic resonance imaging （fMRI） and focusing on brain networks of cognition and emotion, as well as the interaction of these two networks. While inconsistencies and debates noted, the present paper attempts to review and provide a summarized finding for these recent fMRI studies. Converging results have shown that MDD is associated with significant alterations in the fronto-limbic system. Specifically, compared with healthy controls, individuals with MDD usually show hyperactivation to negative facial stimuli in the amygdala, reflecting increased withdrawal, the core syndrome of depression. Some studies have also attempted to use hyperactivities of amygdala as the biomarker and reported its predictive value for MDD. Besides amygdala, increased insula response to disgusting faces was also reported in literature, emphasizing the role of disgust in emotional dysregulation. Cognitive abnormalities in depression mainly concern the default mode and executive control networks. In addition to alterations of regional activation in task state, individuals with MDD exhibit increased functional connectivity of the default mode network in resting state, suggesting enhanced self-referential processes. In particular, higher functional connectivity in the anterior default mode network corresponds with higher level of rumination. In the executive control network, many previous studies observed a decreased activation of dorsolateral prefrontal cortex in depression, indicating impaired ability of cognitive control. At t