The Study Of Brain Network Adjustment Patterns Before And After Cognitive Behavioral Therapy In Patients With First Episode Mild To Moderate Depression

MDD patients usually suffer from a series of emotional and cognitive impairments,which is closely related to specific patterns of brain functional network dysfunction.So depression is often characterized as a network-level neural disorder.CBT therapy can improve the cognitive function of the depressive patients and improve the function at network-level to produce therapeutic effects,but the specific mechanism of CBT therapy is not yet clear.In order to explore the therapeutic mechanism of CBT therapy in treating patients with depression,and to explore the possible neural network regulation model,33 depression drug-naive patients were enrolled in the TO stage(before treatment),T1 stage(6 weeks after CBT treatment)and T2 stage(28 weeks after maintenance treatment),and 27 healthy control group patients with resting state magnetic resonance(r-fMRI)scan data.Using the following steps to conduct data analysis:(1)Using the Independent Component Analysis to extract three core resting state functional networks which are closely related to cognitive function:Salience Network.Central-executive Network,Default State Network.And using one sample T test to obtain the consistent spatial map of the network at various stages and in the healthy control group.(2)Using the repeated measurement analysis of variance in the group to analyze the results of independent component analysis,and the most different functional regions of the brain in the three stage of the treatment was used as a region of interest for the post test.(3)Using voxel-based morphometry method extraction volume of gray matter in the brain to conduct difference testing,and to observe the possible existence of covariant relations.(4)Granger Causal Analysis is used to analyze the causality between the three core function network in time series.The results of the study are as follows:(1)Through the single sample t-test of ICA results,the spatial distribution map of the network in different stages of treatment and healthy controls was obtained.The main region of SN is anterior cingulate cortex and anterior insula.CEN is prefrontal cortex,parietal lobe and part of the insula.DMN is posterior cingulate cortex and ventromedial prefrontal cortex.(2)Variance analysis showed that the right inferior parietal lobule(rIPL,F = 8.06,p<0.01),the right insula(rInsula,F = 22.95,p<0.01)of the CEN,and the left ventromedial prefrontal cortex(1vmPFC,F = 7.05,p<0.01)of the default mode network(DMN)can get significant change in the short term CBT treatment effect,but the post hoc test found the F value of the posterior cingulate region of DMN(PCC,F = 7.28,p<0.01)in the TO stage is slightly higher than control group,T2 stage and TO stage has significant differences in the level ofp<0.05,T2 stage and HC group has significant differences in the level ofp<0.05,T2 stage and T1 stage has significant difference in the level ofp<0.001.(3)Through the VBM measurement the change of gray matter volume in the three stages treatments,found the PCC region which has the function of relevance of the precuneus cortex in the DMN network has significant volume difference(F = 13.1,p<0.001),other network nodes has no corresponding structure change.(4)Using bootstrap based one sample t-test to analysis the random-effect,found that there is a significant positive causal relationship from CEN to SN in healthy control group(Granger Coefficient = 0.32,p = 0.001),but in TO group the GC decreased and shows no significant(GC=0.14,p = 0.054).In T1 group,the GC was significant(GC = 0.21,p = 0.001),and maintained in T2 stage(GC = 0.23,p = 0.006).GC from SN to DMN in the healthy group was not significant(GC =-0.08,p = 0.185),but in TO group GC are significantly abnormal increased(GC = 0.20,p=0.009),and in T1 group GC is no longer significant(GC =-0.12,p = 0.223),significant degree also remained in the stage T2(GC =-0.16 p = 0.134).From the difference of nodes within networks,it is found that the function of rInsula and rIPL as the main nodes within CEN can be improved and maintained under the effect of short term CBT treatment;Within DMN,some changes of functions represented by 1vmPFC have been maintained,but some functions represented by PCC cannot be maintained due to the possible structural changes.These differences indicate that there are some limitations in judging the therapeutic effect of CBT through the nodes within networks,the pattern change of the whole network should be better criterion.From the change of the Grainger causality coefficient,it is found that the functional improvement of CEN gave feedbacks to SN,and the function of DMN is further improved by the regulation of SN.CEN is the first target of the effect of CBT treatment.The prediction of the therapeutic effect of CBT can be first started with CEN and its nodes.