From Orygen, The National Centre of Excellence in Youth Mental Health, Melbourne, Australia; the Centre for Youth Mental Health and the Melbourne Neuropsychiatry Centre, Department of Psychiatry, University of Melbourne, Melbourne; QIMR Berghofer Medical Research Institute, Brisbane, Australia; Metro North Mental Health Service, Brisbane; and the MRI Research Unit, Department of Radiology, Hospital del Mar, CIBERSAM G21, Barcelona, Spain.
Am J Psychiatry. 2017 Sep 1;174(9):895-903. doi: 10.1176/appi.ajp.2017.16080883. Epub 2017 Jun 9.
A disturbed sense of self is a core feature of depression. The medial prefrontal cortex, which has a central role in self-appraisal processes, is often implicated in the illness, although it remains unclear how functional alterations of the region contribute to the observed disturbances. The aim of this study was to clarify the role of the medial prefrontal cortex in self-appraisal processes in depression.
The authors applied a recently developed dynamic network model of self-directed cognition to functional MRI data from 71 adolescents and young adults with moderate to severe major depressive disorder, none of whom were being treated with medication, and 88 healthy control participants. Bayesian model averaging was used to determine parameter estimates for the dynamic causal models, which were compared between groups.
While self-directed cognitive processes in the depression group were shown to rely on the same dynamic network as in the healthy control group, the medial prefrontal cortex had a "hyperregulatory" effect on the posterior cingulate cortex in the depressed group, with self-appraisal causing significantly more negative modulation of connectivity between the medial prefrontal cortex and the posterior cingulate cortex than in the control group (odds ratio=0.54, 95% CI=0.38, 0.77). This parameter was significantly inversely related with a depression factor related to poor concentration and inner tension (r=-0.32; 95% CI=-0.51, -0.08).
The exaggerated influence of the medial prefrontal cortex on the posterior cingulate cortex in depression is a neural correlate of the disturbed self-appraisal that is characteristic of the illness.
自我意识障碍是抑郁症的核心特征。内侧前额叶皮层在自我评价过程中起着核心作用，它常与该疾病相关，尽管其区域功能改变如何导致观察到的紊乱仍不清楚。本研究旨在阐明内侧前额叶皮层在抑郁症自我评价过程中的作用。
作者应用了一种新的自我指向认知的动态网络模型，对 71 名患有中度至重度重度抑郁症的青少年和年轻成年人以及 88 名健康对照组参与者的功能磁共振成像数据进行了分析。贝叶斯模型平均法用于确定动态因果模型的参数估计值，并对组间模型进行了比较。
虽然抑郁组的自我导向认知过程被证明依赖于与健康对照组相同的动态网络，但内侧前额叶皮层对抑郁组后扣带回皮层有“超调节”作用，自我评估导致内侧前额叶皮层和后扣带回皮层之间的连接的负调制显著高于对照组（优势比=0.54，95%置信区间=0.38，0.77）。该参数与与注意力不集中和内心紧张有关的抑郁因子呈显著负相关（r=-0.32；95%置信区间=-0.51，-0.08）。
抑郁症中内侧前额叶皮层对后扣带回皮层的过度影响是该疾病特征性的自我评估障碍的神经相关性。
