Resting State Electroencephalographic Gamma Activity Is Associated With Circadian Preference in Patients With Depression

Abstract

Objective: This study aimed to investigate whether there is a relationship between an individual’s circadian preference and differences in quantitative electroencephalography (QEEG) during the daytime, specifically in patients with mood disorders.Methods: The participants with major depressive disorder, bipolar I disorder, and bipolar II disorder, who had experienced major depressive episodes, were categorized into two or three groups based on their morningness-eveningness preference using the Korean version of the Composite Scale of Morningness (KCSM). The study examined the power of different QEEG bands, such as alpha, beta, theta, delta, and gamma, in the frontal cortex of these patients.Results: The findings indicated that individuals with eveningness preference had significantly lower power in the high gamma band of the right prefrontal cortex compared to those with morningness preference. The average of high gamma powers in the total frontal cortex was also found to be different between the groups. Furthermore, the study revealed a significant association between K-CSM scores and high gamma power, as well as a history of suicide attempts.Conclusion: These results suggest that QEEG may serve as a potential biomarker for circadian preference and suicidality in patients with mood disorders.