PT - JOURNAL ARTICLE AU - Zenas C. Chao AU - Daniel G. Dillon AU - Yi-Hung Liu AU - Elyssa M. Barrick AU - Chien-Te Wu TI - Altered coordination between frontal delta and parietal alpha networks underlies anhedonia and depressive rumination in major depressive disorder AID - 10.1503/jpn.220046 DP - 2022 Nov 01 TA - Journal of Psychiatry and Neuroscience PG - E367--E378 VI - 47 IP - 6 4099 - http://jpn.ca/content/47/6/E367.short 4100 - http://jpn.ca/content/47/6/E367.full SO - JPN2022 Nov 01; 47 AB - Background A hyperactive default mode network (DMN) has been observed in people with major depressive disorder (MDD), and weak DMN suppression has been linked to depressive symptoms. However, whether dysregulation of the DMN contributes to blunted positive emotional experience in people with MDD is unclear.Methods We recorded 128-channel electroencephalograms (EEGs) from 24 participants with MDD and 31 healthy controls in a resting state (RS) and an emotion-induction state (ES), in which participants engaged with emotionally positive pictures. We combined Granger causality analysis and data-driven decomposition to extract latent brain networks shared among states and groups, and we further evaluated their interactions across individuals.Results We extracted 2 subnetworks. Subnetwork 1 represented a delta (δ)–band (1~4 Hz) frontal network that was activated more in the ES than the RS (i.e., task-positive). Subnetwork 2 represented an alpha (α)–band (8~13 Hz) parietal network that was suppressed more in the ES than the RS (i.e., task-negative). These subnetworks were anticorrelated in both the healthy control and MDD groups, but with different sensitivities: for participants with MDD to achieve the same level of task-positive (subnetwork 1) activation as healthy controls, more suppression of task-negative (subnetwork 2) activation was necessary. Furthermore, the anticorrelation strength in participants with MDD correlated with the severity of 2 core MDD symptoms: anhedonia and rumination.Limitations The sample size was small.Conclusion Our findings revealed altered coordination between 2 functional networks in MDD and suggest that weak suppression of the task-negative α-band parietal network contributes to blunted positive emotional responses in adults with depression. The subnetworks identified here could be used for diagnosis or targeted for treatment in the future.