Du Lian, Zeng Jinkun, Liu Huan, Tang Dejian, Meng Huaqing, Li Yongmei, Fu Yixiao
Department of Psychiatry, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, PR China.
Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, PR China.
J Affect Disord. 2017 Jun;215:213-217. doi: 10.1016/j.jad.2017.02.027. Epub 2017 Feb 21.
Suicidal ideation (SI) is highly prevalent and a known symptom of Major Depressive Disorder (MDD), but its underlying biological mechanisms are relatively unknown. Several studies linked suicidal ideation to dysfunctional brain circuits, specifically fronto-limbic connections. The purpose of this work was to investigate fronto-limbic disconnection in MDD patients with or without SI.
MDD patients with SI (SI, n=28) or without SI (NSI, n=20), identified by the Scale for Suicide Ideation and healthy controls (HCs, n=30) underwent resting-state functional MRI scanning. The functional properties of correlations in neural activity (intrinsic functional connectivity, iFC) of the rostral anterior cingulate cortex (rACC) were analyzed among the three groups. Furthermore, correlation analyses between iFC, SI severity and depression severity were performed.
We found that the SI group exhibited decreased iFC between the rACC, the orbitomedial prefrontal cortex and the right middle temporal pole compared to HCs and NSI groups. The NSI group showed decreased iFC between the rACC and the orbitomedial prefrontal cortex compared to HCs. In the SI group, iFC strength between the right rACC and the middle temporal pole positively correlated with SI severity.
Transdiagnostic and diagnosis-specific alterations of fronto-limbic iFC were found in MDD patients with or without SI. Disrupted fronto-limbic circuits may impact decision-making and emotional processing in SI. These results provide useful information about the pathophysiological mechanisms of MDD patients with SI.
自杀观念（SI）非常普遍，是重度抑郁症（MDD）的一种已知症状，但其潜在的生物学机制相对尚不明确。多项研究将自杀观念与功能失调的脑回路联系起来，特别是前额叶 - 边缘叶连接。这项研究的目的是调查有或无自杀观念的MDD患者的前额叶 - 边缘叶连接中断情况。
通过自杀观念量表确定的有自杀观念的MDD患者（SI组，n = 28）或无自杀观念的MDD患者（NSI组，n = 20）以及健康对照者（HC组，n = 30）接受静息态功能磁共振成像扫描。分析了三组之间喙突前扣带回皮质（rACC）神经活动相关性的功能特性（内在功能连接性，iFC）。此外，还进行了iFC、SI严重程度和抑郁严重程度之间的相关性分析。
我们发现，与HC组和NSI组相比，SI组在rACC、眶额内侧前额叶皮质和右侧颞中极之间的iFC降低。与HC组相比，NSI组在rACC和眶额内侧前额叶皮质之间的iFC降低。在SI组中，右侧rACC与颞中极之间的iFC强度与SI严重程度呈正相关。
在有或无自杀观念的MDD患者中发现了前额叶 - 边缘叶iFC的跨诊断和诊断特异性改变。前额叶 - 边缘叶回路中断可能会影响自杀观念中的决策和情绪处理。这些结果为有自杀观念的MDD患者的病理生理机制提供了有用信息。
