Altered functional connectivity in emotional subregions of the anterior cingulate cortex in young and middle-aged patients with major depressive disorder: A resting-state fMRI study

It has been demonstrated that the anterior cingulate cortex (ACC) has three subregions, involved in behavior, cognition, and emotion. However, the intrinsic connectivity of the ACC subregions in patients with major depressive disorder (MDD) is still unclear. In this study, functional magnetic resonance imaging (fMRI) data was used to detect the functional connectivity (FC) of ACC subregions and the correlation with the disease severity in young and middle-aged patients with MDD.A total of 36 young and middle-aged patients with first-episode MDD and 36 healthy controls (HCs) were enrolled in this study. FC was applied to investigate altered connectivity of the ACC subregion in MDD patients compared to HCs. Correlation analysis was then used to assess possible relationship between the neuroimaging findings and clinical symptoms in the patient group.Compared to HCs, young and middle-aged patients had significantly decreased FC between the emotional subregion of the ACC and the hippocampus, thalamus, insula, angular gyrus, and posterior cingulate cortex. The FC between the ACC emotional subregion and the insula, the AG, the RPHG was negatively correlated with depression index. The FC between the ACC emotional subregion and the putamen was positively correlated with depression index.The present findings indicate that abnormal ACC subregions-seeded FC may be implicated in the MDD-related abnormalities of emotion regulation and information processing. And there is a correlation between the above FC changes and the clinical symptoms of young and middle-aged MDD patients. This study may provide preliminary evidence for the ACC-related neural mechanism in young and middle-aged MDD patients and enhance the understanding of the pathophysiology of MDD.