A Comparative Study Of Resting-state Functional Connectivity In First-episode Mild To Moderate Depression Based On Default Mode Network

Objective（1）Applying resting-state functional Magnetic Resonance Imaging（rs-f MRI）functional connectivity（FC）analysis method Comparative analysis to find abnormalities in the brain network of patients with first-episode mild to moderate depression,and provide a basis for neuroimaging for the pathological mechanism of depression;（2）To explore the characteristics of default mode network functions in patients with first-episode mild to moderate depression;（3）To explore the relationship between brain function abnormalities and clinical symptoms in patients with first-episode mild to moderate depression.Methods Twenty-four patients with first-episode mild to moderate depression（depression group）were selected[consistent with Diagnostic and Statistical Mamual of Mental Disorder,Fourth Edition,（DSM-IV）depression,with a total score of 18-24 on the HAMD₁₇score]and Clinically recruited 22 normal controls（control group）matched in gender,age,education level,hands and depression group for rs-f MRI scan,routinely preprocessed with DPARSFA software based on MATLAB,the whole brain functional connection analysis was performed with m PFC and PCC as the seed point.The two-sample t test was used to compare the differences between the groups.In order to increase the normality of the data,Fisher r-to-Z transformation was used to perform statistical analysis.Pearson correlation analysis was performed for the statistically different brain area FC values with the HAMD₁₇score and the total course of disease.Results Compared with the control group,m PFC in the depression group had reduced functional connectivity with the bilateral cerebellar lobes,the right anteriorcingulate gyrus,the right orbital frontal gyrus,and the left precuneus;m PFC in the depression group had functional connectivity increased with frontal inferior opercularis gyrus（P<0.05,K>54）;compared with the control group,PCC in the depression group had reduced functional connectivity with bilateral orbital frontal gyrus,bilateral putamen,and left dorsal lateral frontal gyrus,and with the increased functional connectivity in the left medial temporal gyrus,bilateral angular gyrus,and right precuneus（P<0.05,K>54）;the above-mentioned FC abnormal brain regions were not correlated with HAMD17 scores,and the left orbital frontal gyrus and PCC FC decrease（r=-0.415,P=0.044）,decrease in FC between the left anterior wedge and m PFC（r=-0.462,P=0.023）was negatively correlated with the disease course,and the right anterior cingulate gyrus and decrease in FC between m PFC were positive Correlation（r=0.494,P=0.014）.Conclusions（1）In patients with first-episode mild to moderate depression,there are abnormal functional connectivity in the DMN and the brain region out of the DMN,including functional connectivity in the dorsal lateral prefrontal lobe,orbitofrontal cortex,cingulate gyrus,precuneus,angular gyrus,and cerebellar hemisphere.Abnormalities,suggesting that these brain region dysfunctions may be the pathological basis of depression,and may be the biological basis of some clinical symptoms of depression;（2）some of the first-episode mild to moderate depression patients with abnormal brain functional connectivity are related to the course of disease,may be provide evidence for the development and changes of the disease,and provide imaging evidence for the diagnosis and screening of mild to moderate depression.