Comparison Of Cognitive Function Network Between First-Episode Medication-Naive And Remitted Phase Of Major Depressive Disorder Based On FMRI

Antidepressants are recommended as the first line of treatment for major depressive disorder(MDD),along with high incidence rate,high disability and high suicide rate.Previous studies have found cognitive dysfunction in depression was associated with abnormal cognitive control networks,including cognitive control network(CCN),default mode network(DMN),and salience network(SN).Based on independent component analysis(ICA),this article aims to make a deep understand of pathological and recovery mechanisms of MDD by comparing differences of cognitive function networks between first episode medication-naive MDD(fMDD)and remitted phase of major depressive disorder after treatment by antidepressants(rMDD).fMDD(n = 22),rMDD(n = 21)and healthy control groups(HCs)matched with age,sex and education(n = 20)were enrolled and then accepted general survey,clinical assessments by 17-items Hamilton depression rating scales(HAMD-17)and scanning of resting state functional magnetic resonance(rs-fMRI).We selected CCN,DMN and SN matched the established templates from the three groups using ICA.Using Analysis of Variance(ANOVA)and post hoc t test,we statistically analyzed mean values of Z-maps in CCN,DMN and SN.In addition,multiple regression analysis was applied to investigate the relationship between scores of HAMD-17,cognitive dysfunction factor and cognitive functional networks.Results are as followings:(1)Among cognitive functional networks,differences regions in CCN(F(2.53)=6.84)are mainly located in dorsolateral prefrontal cortex,parietal lobes,supramarginal gyrus,insula,dorsal cingulate,in DMN(F(2.53)=10.74)are located in medial frontal gyrus and cingulate regions,as well as in SN(F(2,53)= 6.90)are in middle frontal gyrus,right precentral gyrus and supplementary motor area(FDR corrected,p<0.01).(2)Compared with HCs,activity level of right lateral dorsolateral prefrontal cortex,left inferior parietal lobule and bilateral supramarginal gyrus in CCN of fMDD group were lower,while right inferior parietal lobule,right lateral cingulate gyrus and right insula were higher than those in HCs;the activity level of bilateral superior frontal gyrus and left lentiform shell in DMN were higher;activity level of bilateral precentral gyrus,right supplementary motor area,left superior frontal gyrus and left cingulate in SN are lower,while bilateral supplementary motor area,medial superior frontal gyrus and left frontal gyrus were higher(p<0.01).(3)Compared with HCs,activity level of bilateral dorsolateral prefrontal cortex,inferior parietal lobule and left superior parietal in CCN of rMDD group were lower,and activity level of bilateral insula and right dorsal cingulate were higher;activity level of the right cingulate and right angle were higher in DMN;as well as right superior temporal gyrus was lower;in addition,activity level of right middle frontal gyrus,bilateral superior frontal gyrus and right medial frontal in SN were lower,while the left supplementary motor area and right medial frontal gyrus were higher(p<0.01),(4)Compared with fMDD,activity level of parietal areas in CCN of rMDD was lower,right dorsolateral prefrontal cortex and insula were higher;activity level of medial superior frontal gyrus,right cingulate gyrus and right inferior temporal in DMN were higher,left superior frontal gyrus,left medial superior frontal gyrus,right angular gyras and right middle frontal gyrus were lower;activity level of the left middle frontal gyrus,left medial frontal gyrus,left lentiform shell and supplementary motor area in SN were lower,while supplementary motor area,superior frontal gyrus,right middle frontal gyras and right precentral gyrus were higher(p<0.1).This study concluded that:(1)Activity levels in CCN and SN of fMDD were significantly lower,and in DMN were significantly higher,which were related with lower ability of cognitive function,which may reflect that fMDD patients had low ability of cognitive control.(2)Though activity levels in cognitive function network were improved in rMDD while compared with HCs,there were still significant anomalies,especially in CCN.It may be the main cause of residual symptoms and relapse.Superior temporal gyrus may play an important role in recovery of cognitive function.(3)Activity levels in cognitive function network of rMDD still has significantly abnormality,especially in insula and anterior cingulate cortex which may play a compensatory role in the improvement of cognitive control function.(4)Lower activity of precentral gyrus in SN which involved in executive function of response inhibition may reflect that mild to moderate(Mean±SD(HAMD-17)=25.5±4.7)of MDD with lower patients have small possibility of suicide.