The aberrant effective connectivity of the limbic system to happy face in patients with depression / 中华行为医学与脑科学杂志

ABSTRACT

Objective To investigate the effective connectivity of limbic circuit in patients with major depressive disorder when they recognized dynamic positive face expressions,aiming to discuss the possible mechanism of emotion processing in depressed patients.Methods Eighteen depressive patients and eighteen well-matched healthy control volunteers participated in the experiment.All subjects were asked to recognize the emotion face during the magnetoencephalograph (MEG) scanning.The regions of interested (ROI) brain areas included the orbital frontal cortex (OFC),the anterior cingulated cortex (ACC),the amygdala (AMYG),the hippocampus and the insula.The MEG data were preprocessed by the SPM8 software and further analyzed by the Granger casual model (GCM).The non-parameter permutation was used to compare the value of effective connectivity between the healthy controls and the depressed patients.Results Compared with healthy controls,the effective connectivity from the ACC to the AMYG (P=0.0052),from the OFC to the AMYG(P=0.0046),from the Hippocampus to the ACC (P=0.0016),and from the ACC to the Hippocampus (P=0.0042)was significantly reduced in depressed patients.Conclusion The depressed patients display decreased interaction of the limbic circuit during the happy facial emotion processing,indicating that the depressed patients are unable to deal with the positive stimuli,and to certain extent,explaining the abnormal neuropathophysiological mechanism of positive stimuli in MDD.