Excessive propagation of right frontal beta oscillations in patients with a history of major depressive disorder.

Patients suffering from various neurological disorders, including major depressive disorder (MDD), often exhibit abnormal brain connectivity. In particular, patients with MDD show atypical brain oscillations propagation. This study aims to investigate an association between abnormal brain connectivity and atypical oscillatory propagation of electroencephalogram (EEG) signals in patients with a history of MDD. Previous findings of functional hyperconnectivity in beta oscillations (15-25 Hz) lead us to hypothesize that patients would experience abnormal beta oscillation propagation. Using the local phase gradient (LPG) method, we analyze a publicly available EEG dataset recorded during a probabilistic learning task. Our findings indicate that, upon receiving positive feedback during the learning task, patients with a history of MDD show more pronounced propagation directions of beta oscillations observed in the right frontal region compared to healthy controls. This directional pattern may help differentiate patients with a history of MDD from healthy controls. The observed abnormalities in brain oscillation propagation suggest that cognitive deficits in patients with a history of MDD might stem from excessive and negatively biased information transmission between brain regions.

Supplementary information: The online version contains supplementary material available at 10.1007/s13534-024-00433-9.