Disrupted brain network dynamics and cognitive dysfunction in drug-naive major depressive disorder: an EEG microstate...

Dysfunctions in brain network dynamics have been linked to emotional disorders. However, there is limited research exploring the connection between resting-state EEG brain networks and cognitive functions in individuals with Major Depressive Disorder (MDD). The objective of this study is to examine irregular brain network activity and its relationship with cognitive performance, utilizing EEG microstates, in order to shed light on the underlying neuropathological mechanisms of MDD. This study included 68 drug-naïve MDD individuals and 50 healthy control participants (HCs). Demographic data were collected, and cognitive function assessments were performed. Concurrently, resting-state brain activity was captured using a 64-channel EEG. Additionally, Pearson correlation analysis was used to explored the relationship between these factors in MDD patients. We identified four distinct EEG microstate topographic maps. In comparison with the healthy control group, the coverage, duration, and occurrence of microstates A and D were significantly diminished, whereas those of microstate B were markedly increased. The performance on various neurocognitive tests (Trail Making Test [TMT], Symbol Digit Modalities Test [SDMT], Stroop Color-Word Test [SCWT]) for the MDD group was consistently lower than that of the HCs. In the MDD patients, all parameters of microstate A exhibited a negative correlation with Stroop's color-naming and word-color time, while the coverage and duration of microstate D correlated positively with scores on the SDMT. Our study indicated that individuals with MDD display aberrant microstate dynamics, and these results corroborate the link between alterations in microstate activity and cognitive function in MDD patients.