Anxiety and sleep disorders in depressed patients are affected by resting state EEG rhythm

Abstract

Abstract Background Depression is a complex mental disease whose typical symptoms include sleep disturbances and anxiety, which often co-occur, further aggravating the patient's condition. The study aimed to investigate the relationship between EEG rhythms and sleep disorders and anxiety conditions in depressed patients, as well as physiologic indicators that may contribute to these changes. Methods Resting-state EEG data from 24 depressed patients and 24 healthy subjects were used to analyze EEG signal power in different frequency bands. Explored the relationship between EEG frequency bands and anxiety symptoms (assessed using the GAD-7 scale) and sleep quality (using the Pittsburgh Sleep Quality Index Scale, PQSI) through multiple regression analysis. Using the sLORETA technique, EEG source analysis was conducted to compare current densities in different brain regions between depressed patients and healthy controls. Results Compared with the HC group, there were significant differences in localized electrode power in major depressive disorders (MDD), focusing on electrodes in temporal, frontal, and occipital regions. Regression analysis showed that symptoms of GAD(GAD-7 score) were affected by the Beta band power, while sleep quality (PQSI score) was affected by the Alpha band power. Source localization analysis revealed that there were greater differences in current density in temporal lobe (STG, ITG, FG) and frontal lobe (IFG) in the MDD group, compared to the HC group. Conclusion The findings suggest that there is a close correlation between sleep disorders and Alpha band power in depressed patients, potentially indicating functional abnormalities in the left temporal lobe region as well as left lateralized asymmetrically of the Alpha band. In addition, abnormal functioning of the inferior temporal gyrus (IFG) and the fusiform gyrus (FG) in depressed patients may lead to symptoms of anxiety. The difference in current density in the temporal and frontal lobes reflects the abnormal brain activity in these regions in depressed patients and is a significant physiological marker of depression. Significance: These discoveries contribute to an in-depth understanding of the characteristics of EEG activity in patients with depression and provide new research directions for future treatment and intervention.