Decreased static and increased dynamic global signal topography in major depressive disorder.

Major depressive disorder (MDD) has been linked to imbalanced communication among large-scale brain networks. However, the details of altered large-scale coordination of MDD remains unknown. To explore the altered large-scale functional organization in MDD. We used static and dynamic global signal (GS) topography, which are data-driven methods to explore altered relationship between global and local neuronal activities in MDD. Sixty three MDD patients and matched 63 healthy controls (HCs) were recruited in current study. Patients with MDD presented decreased static GS topography in bilateral parahippocampal gyrus and hippocampus gyrus. Meanwhile, patients with MDD presented increased variability of dynamic GS topography in the right ventromedial prefrontal cortex. This result may reflect the decreased and unstable whole brain functional coherence in MDD. The decreased static GS topography in the right parahippocampal gyrus was correlated with psychomotor retardation in patients with MDD. Our results presented that the altered static and dynamic GS topography can provide distinct evidence on the physiological mechanisms of MDD.