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.

自我感受到困扰是抑郁症的核心特征。尽管尚不清楚该区域的功能改变如何导致观察到的疾病，但在自我评估过程中起着核心作用的内侧前额叶皮层通常与疾病有关。这项研究的目的是阐明在抑郁自我评估过程中内侧前额叶皮层的作用。

作者将最近开发的自我导向的认知动态网络模型应用于来自71名中度至重度严重抑郁障碍（未接受药物治疗）的青少年和88名健康对照者的功能性MRI数据。贝叶斯模型平均用于确定动态因果模型的参数估计值，并在组之间进行比较。

抑郁组的自我指导认知过程显示出与健康对照组相同的动态网络，而前额内侧皮层对抑郁组的后扣带回皮质具有“过度调节”作用，并进行自我评估导致内侧前额叶皮层和后扣带回皮层之间的连通性的消极调节比对照组显着更多（优势比= 0.54、95％CI = 0.38、0.77）。此参数与与不良浓度和内部张力有关的抑郁因素成反比（r = -0.32； 95％CI = -0.51，-0.08）。

抑郁症中前额叶皮质对后扣带回皮质的夸大影响是疾病自我表征的神经干扰。