The Resting-state Functional Magnetic Resonance Imaging Study Based On Functional Connectivity In Patients With First-episode Mild To Moderate Depression

Objective:By using resting-state functional magnetic resonance imaging technique,to study the functional connectivity of bilateral amygdala and insula in first-episode mild to moderate patients with major depressive disorder(MDD)during resting-state.Methods:Sixteen first-episode mild to moderate patients with MDD and sixteen healthy controls underwent resting-state functional magnetic resonance imaging(rs-fMRI)scan.Routine preprocessing the of rs-fMRI data was performed,Four seed points of bilateral amygdala and insula were selected for whole-brain functional connectivity analysis.Two-sample t-test was used to compare the difference of functional connectivity between the two groups.Pearson correlation analysis was performed between the FC values of brain regions with statistically significant differences and 24-items Hamilton Depression Scale scores.Results:In comparison to the control group,the MDD patients showed increased FC between the left amygdala and the bilateral inferior temporal gyrus,the right thalamus,the left inferior parietal gyrus and the right superior frontal gyrus;The right amygdala showed increased FC with bilateral middle frontal gyrus,bilateral caudate nucleus,the right medial superior frontal gyrus,,the left inferior temporal gyrus and the right angular gyrus(P<0.001,uncorrected).In comparison to the control group,the MDD patients showed increased FC between the left insula and the right superior frontal gyrus,the left middle frontal gyrus,bilateral pallidum and the left caudate nucleus;The right insula showed increased FC with the bilateral middle frontal gyrus,the right inferior temporal gyrus,the left cingulate gyrus,the left postcentral gyrus and the left caudate nucleus(P<0.001,uncorrected).No significant correlation was found between the FC values in the above mentioned brain regions and 24-items HAMD scores(P>0.05).Conclusion:Patients with first-episode mild to moderate depression probably have abnormal FC in amygdala and insula,which showed increased functional connectivity with the prefrontal lobe,the temporal lobe,the angular gyrus,the caudate nucleus and the cingulate gyrus.Abnormal functional connectivity maybe related to the neuropathological mechanism of depression.Objective:To explore the resting-state functional connectivity changes of insular subdivisions in patients with first-episode mild to moderate depression by resting-state functional connectivity analysis,which would provide new ideas and directions for the pathogenesis of depression.Methods:Sixteen patients with first-episode mild to moderate depression and sixteen healthy controls underwent resting-state functional magnetic resonance imaging(rs-fMRI)scan.Routine preprocessing the of rs-fMRI data was performed,the insula was divided into the anterior insula,the middle insula and the posterior insula.Whole-brain functional connectivity analysis was performed with the above mentioned six seed points.Among the two groups,the FC of each seed with significant differences were calculated with two-sample t-test and multiple comparison correction of Gaussian random field theory(GRF).Pearson correlation analysis was performed between the FC values of brain regions with statistically significant differences and 24-items Hamilton Depression Scale scores.Results:In comparison to the control group,the MDD patients showed increased FC between the left anterior insula and the right superior frontal gyrus,the right middle frontal gyrus and the right precentral gyrus(P<0.05);The right anterior insula showed increased FC with bilateral superior cerebellum and Vermis(P<0.05).In comparison to the control group,the MDD patients showed increased FC between the left middle insula and the right superior frontal gyrus,the right middle frontal gyrus and the right precentral gyrus(P<0.05);The right middle insula showed increased FC with right superior frontal gyrus and right middle frontal gyrus(P<0.05).In comparison to the control group,the MDD patients showed increased FC between the left posterior insula and bilateral middle frontal gyrus,the left precentral gyrus,the right superior frontal gyrus,the right inferior frontal gyrus,the right occipital gyrus,the right angle gyrus,the right medial and lateral cingulate gyrus,the right thalamus and the right caudate nucleus;the right posterior insula showed increased FC with bilateral superior frontal gyrus,bilateral middle frontal gyrus,the left thalamus,the left caudate nucleus,the left Putamen and brainstem(P<0.05).There was no significant correlation between FC and 24-items HAMD scores(P>0.05).Conclusion:1.FC was increased between insular subdivisions and prefrontal cortex,the left precentral gyrus,cingulate gyrus,occipital lobe,basal ganglia and cerebellum in patients with first-episode untreated mild to moderate depression,which may be involved in the pathogenesis of depression;2.The damage of prefrontal-limbic system in the first untreated mild to moderate depression may be related to the pathogenesis of depression.