Characteristics Of Cool Executive Function And EEG In Patients With Depression

BackgroundDepression disorder is a common disorder of brain function in psychiatric department,which is characterized by high incidence,high recurrence rate and prolonged course.There are emotional symptom group,somatic symptom group and cognitive symptom group,among which cognitive symptom group are the key factor that lead to symptom delay,poor recovery and relapse.Cool executive function(Cool EF)is the core component of cognitive function.The characteristics of brain function changes in patients with depression during Cool EF tasks are not clear.The aim of this study was to understand the Cool EF and the electroencephalogram(EEG)physiological characteristics of the patients with depression,and to provide reference for the Cool EF and the electroencephalogram(EEG)physiological mechanism.ObjectiveTo investigate the characteristics of Cool EF and EEG in patients with depression.MethodsThirty-four patients who met the diagnostic criteria of DSM-IV depression and 39 healthy controls matched with gender,age and years of education were included.General data,clinical characteristics and cognitive function scores were collected by using the General Data Test,Hamilton Depression Scale-24 items(HAMD-24)and MATRICS Consensus Cognitive Battery(MCCB).The EEG data of resting state,Stroop task and Oneback task were collected in 22 patients and 18 healthy controls.EEG was collected using the German Brain Products Easy Cap Gmb H EEG system with 64 leads,and the electrode distribution was in line with the international 10-20 lead system.The EEG data were preprocessed based on EEGLAB toolkit on MATLAB platform.Phase locking value(PLV)was used to construct brain functional networks,and independent sample t test was used to analyze differences in brain functional connections.The clustering coefficient and the length of the characteristic path reflect the topological attributes of the differential network.The behavioral data and EEG data were comprehensively analyzed using SPSS21.0.ResultsThe behavioral results showed that there were significant differences in Trail Making Test A,Mazes Test,Hopkins Verbal Learning Test Revised,Brief Visuospatial Memory Test,Spatial Span Test,Stroop Test between the two groups(P < 0.05).After controlling for age and years of education,the scores of Spatial Span Test were negatively correlated with total score of HAMD and anxiety/somatic factors(r values were-0.498 and-0.455;P valules were 0.004 and 0.009).The scores of Stroop color-words were negatively correlated with the scores of delay factor(r=-474,P=0.006).The resting-state EEG found that functional connections in the frontal,and central regions were stronger in the β band in depression group than in the healthy group(FDR corrected,P<0.05).After controlling for age,sex and years of education,the clustering coefficient was negatively correlated with HAMD score and anxiety/somatization factors(r values were-0.560 and-0.547,P values were 0.016 and 0.014).The length of characteristic pathway was positively correlated with HAMD score and anxiety/somatization(r values were 0.551 and 0.553,P values were 0.018 and 0.017).The results of Stroop Task showed that the response times(RTs)of the depression group were significantly higher than that of the healthy group(t values were 2.410 and 2.608;P values were 0.021 and 0.013),and there was no significant difference in accuracy(ACC)(P>0.05).Under inconsistent conditions,functional connectivity of the left frontal,parietal,and temporal lobes in the δ band was stronger in the depression group than in the healthy group(FDR corrected,P<0.05);In the θ band,functional connectivity of the left frontal,temporal,parietal,and occipital lobes was stronger in the depression group than in the healthy group(FDR corrected,P<0.05).After controlling for age,sex and years of education,there was a significant positive correlation between the clustering coefficient and RTs(r=0.514,P=0.028),and the characteristic path length was negatively correlated with the RTs(r=-0.534,P=0.018).The results of the One-back Task showed that the RTs of the depression group was greater than that of the healthy control group(t=2.212,P=0.033),and the difference in the ACC was not statistically significant(P>0.05).At judgment stage,δ frequency,functional connectivity of the left frontal,temporal,and parietal lobes was stronger in the depression group than in the healthy group(FDR corrected,P<0.05).Taking age and years of education as control variables,the clustering coefficient was positively correlated with the RTs(r=0.445,P=0.049),and the length of characteristic path was negatively correlated with the RTs(r=-0.458,P=0.042).ConclusionPatients with depression showed Cool EF impairment,especially reaction speed,conflict monitoring and working memory,and the more severe the symptoms,the more serious the impairment.The Cool EF impairment may be related to the abnormal enhancement of functional connections among the left frontal,parietal and temporal networks.