Abnormalities in EEG microstates among individuals with major depression and obsessive- compulsive disorder

Abstract Electroencephalogram microstate analysis is a valuable tool for studying the rapid dynamics of large-scale brain networks. Research has shown that microstate changes are associated with mental disorders, particularly major depressive disorder (MDD) and obsessive-compulsive disorder (OCD). Despite their frequent comorbidity and symptomatic overlap, MDD and OCD often require different treatment approaches. By analyzing the patterns of microstates in individuals with OCD, MDD and a control group, we aim to improve our understanding of the neural pathways involved in these disorders. Resting state EEG data were collected from 32 individuals diagnosed with MDD, 26 individuals with OCD and 40 healthy controls. The results showed that the duration, occurrence and coverage of microstate C were significantly higher in the OCD group than in the MDD group. Conversely, both the duration and coverage of microstate D were lower in the OCD group than in MDD and controls. A negative correlation was found between Beck Depression Inventory scores and the duration and coverage of microstate A specifically within the OCD group. Our study revealed that the microstate patterns observed in MDD and OCD were markedly distinct, with microstates A, C, and D emerging as the most indicative in the context of OCD.