A Study Of Functional Connectivity Of The Amygdala And Its Subregions After Clinical Remission Of Depression

Major depressive disorder(MDD)has a high prevalence rate and a high recurrence rate.Although the depressive symptoms of patients have different degrees of remission after antidepressant treatment,more than 90% of the remitted major depressive disorder(rMDD)patients still have residual symptoms and psychosocial functioning impairment.Changes of amygdala functional connectivity(FC)provide us an indication of the recovery of neural mechanisms in MDD patients.Previous studies have found abnormal amygdala FC in rMDD patients.However,the amygdala was not selected as ROI and separated into different subregions.Therefore,in order to provide cognitive neuroscience indicators for the recovery of rMDD patients,this study will select amygdala and its subregions as ROIs to explore abnormal amygdala resting state FC and its correlation with residual depressive symptoms and psychosocial functioning.In this study,34 subjects in rMDD group and 25 subjects in healthy control(HC)group were enrolled respectively.The demographic data,clinical scale data and f MRI data of the subjects were collected within 1 week after enrollment.In the first part,the resting state FC method was used to compare the differences of FC of the amygdala and its subregions(BLA,CMA,SFA,AStr)between the rMDD group and the HC group.In the second part,correlation analysis was conducted between abnormal amygdala FC and score of Beck Depression Inventory(BDI),psychosocial functioning to explore the relationship between abnormal amygdala FC and residual depressive symptoms,psychosocial functioning.The main results are as follows:(1)The results of independent sample t-test(Alpha Sim correction,p<0.001)showed that: Compared to HC group,the FC between left amygdala and left postcentral gyrus(t=-6.99),STG(t=-5.90),bilateral insula(left: t=-4.45;right: t=-4.21),middle cingulate gyrus(t=-3.66),m FG(t=-4.3)decreased,the FC between left amygdala and right IPL(t=4.24),SPL(t=3.98),precuneus(t=4.77)increased in rMDD group.The FC between right amygdala and bilateral insula(left: t=-4.82;right:t=-5.50),left STG(t=-5.47),middle cingulate gyrus(t=-5.11),m FG(t=-3.91)decreased,the FC between right amygdala and precuneus(t=5.46)increased.The FC between CMA and left insula(t=-4.08)decreased.The FC between AStr and bilateral insula(left: t=-4.55;right: t=-3.51),thalamus(t=-5.00),bilateral supplementary motor area(t=-4.61)decreased.The FC between BLA and bilateral insula(left: t=-4.34;right:t=-6.33),thalamus(t=-6.89),STG(left: t=-6.41;right: t=-4.90)decreased.The FC between BLA and right SPL(t=4.78),IPL(t=3.77),precuneus(t=3.67)increased.(2)The results of Pearson correlation analysis showed that: in rMDD group,the FC between left amygdala and right insula was positively correlated with physical function(r=0.347,p<0.05).The FC between right amygdala and left insula was negatively correlated with physical function(r=-0.361,p<0.05),psychological function(r=-0.393,p<0.05),social function(r=-0.436,p<0.05).The FC between BLA and right insula was positively correlated with social function(r=0.346,p<0.05).The FC between BLA and left STG was negatively correlated with physical function(r=-0.378,p<0.05),social function(r=-0.36,p<0.05).The FC between BLA and left insula was negatively correlated with psychological function(r=-0.355,p<0.05).The FC between AStr and right insula was negatively correlated with psychological function(r=-0.375,p<0.05).The FC between right amygdala and m FG was negatively correlated with BDI(r=-0.358,p<0.05).The FC between BLA and right SPL was positively correlated with BDI(r=0.375,p<0.05).This study draws the following conclusions:(1)In rMDD group,the abnormal FC between amygdala and its subregions and insula,precuneus,SPL,IPL may be related to dysfunction of emotion and cognition.(2)In rMDD group,the abnormal FC in amygdala and its subregions was significantly correlated with psychosocial functioning and residual depressive symptoms.FC of amygdala and its subregions in rMDD patients can reflect the recovery of psychosocial functioning and depressive symptoms.(3)In rMDD group,the abnormal FC in the whole amygdala and its subregions not only overlaps but also differs,among which the FC abnormality mainly occurs in BLA.