The Changes of Brain Network Efficiency in Patients With Major Depressive Disorder Estimated by Intrinsic Functional Connectivity

Abstract

This study focused on the changes of network topological efficiency under the condition of maximizing the intrinsic functional connectivity, and explored the relationships between altered topological efficiency and depressive psychopathology. For this purpose, we collected the resting-state functional MRI data from 20 major depressive disorder (MDD) patients and 20 healthy control (HC) individuals with matching of age, gender and education level. Graph theory analysis showed that the patients with MDD exhibited significantly reduced nodal efficiency in the left parahippocampal gyrus, right amygdala, left heschl and left temporal pole (middle temporal gyrus) compared with the HC group. The reduced nodal efficiency indicated that the function of transmitting information to other regions was weakened in MDD patients. The local efficiency of the left medial superior frontal gyrus, left orbital superior frontal gyrus, right rectus, left amygdala, right superior parietal gyrus, left thalamus, and left temporal pole (middle temporal gyrus) were also significantly reduced. And the local efficiency of the left medial superior frontal gyrus, left amygdala, left thalamus had negative correlation with PHQ-9. The reduced local efficiency implied that the ability of information transmission at the local level was damaged in the depressed brain network. These results suggested that the prefrontal-thalamo-limbic system involving affective processing was damaged in MDD patients. Our findings might provide a potential biomarker for the clinical diagnosis of depressed patients.