Relationship between dynamic neural activities and clinical symptoms in depression

Abstract

Introduction: Neurophysiological research in Major Depressive Disorder (MDD) has indicated pattern of electroencephalography (EEG) activity that distinguishes MDD patients from healthy subjects. Using EEG spectral power and current source density (CSD) analysis, our study aimed to examine the relationship between dynamic neuronal activities and clinical depressive symptoms. Methods: 20 MDD patients (mean age: 47; male: 7) were compared with 20 healthy subjects (mean age: 51; male: 8). Spectral power was calculated from 8 min artifact free data on each frequency. Electrode sites on each hemisphere were pooled for analysis. One minute CSD power was obtained from sLORETA. EEG data were correlated with clinical symptoms measured with BDI, HDRS, MARS, TMT, Stroop and PSQI. Results:There were positive correlations between TMT and EEG power in beta and gamma bands at centroparietal region (p < .008). The frontal CSD in delta and beta power was associated with Stroop task (p < .002). Worse sleeping quality was also found to be associated with higher power temporoparietal in beta and gamma bands. BDI was correlated with the left frontal power in beta band (p < .008). Conclusion:These findings confirm that depressive symptoms in MDD patients have neurofunctional expressions in the EEG domain. The severity of depression is associated with left frontal activity, while cognitive and sleep disturbances are associated with higher frequency activity in centro-temporo-parietal brain regions.