A study on the change of resting state functional connection of default mode network in clinically remitted patients with major depression disorder / 中华行为医学与脑科学杂志

ABSTRACT

Objective:To explore the functional connection (FC) changes of default mode network (DMN) with the patients who have clinically remitted from major depressed disorder (MDD) and the brain imaging basis of the rehabilitation mechanism of major depression.Methods:Seventeen right-handed outpatients in the medical and psychological ward of Nanjing Brain Hospital who met the inclusion criteria were recruited by psychiatrists.MDD subjects after enrollment were scanned by resting-state functional magnetic resonance (fMRI) in baseline period(rMDD) and a 6-month follow-up period (sMDD). Tweenty-two healthy controls (control group, HCs group) matched with the MDD group in gender, age, and educational level were recruited and given the same resting fMRI scan.The independent component analysis (ICA) was used to extract DMN brain regions of rMDD, sMDD and HCs in resting state separately and to compare the changes of DMN functional connectivity in full remitted MDD patients.Results:The DMN data showed that the functional connectivity of right orbital middle frontal gyrus(MNI x, y, z=3, 54, -9), right posterior cingulate(MNI x, y, z=6, -51, 30), and precuneus(MNI x, y, z=9, -54, 27) in the rMDD was significantly higher than the HCs group, and no functional connectivity in the rMDD was found to be lower than that in HCs group.Furthermore, no significant difference been found between the sMDD and HCs group.Compared with the rMDD, the functional connectivity of orbital middle frontal gyrus(MNI x, y, z=3, 54, -9) and left medial prefrontal cortex (mPFC) (MNI x, y, z=-3, 66, 12)in the sMDD was significantly lower than that in the rMDD, and the functional connectivity of left angular gyrus in the sMDD(MNI x, y, z=-57, -57, 33) was significantly higher than that in the rMDD.Conclusion:The DMN network has not fully returned to its normal level though the posttreatment Hamilton Depression Scale-17 score was lower than 7 points, and the injury of FC is still recovering in the following 6 months, suggesting that the recovery of the DMN network function was delayed in the full remission of clinical symptoms, and is related to the recure of MDD.