Abnormal neural activities in first-episode, treatment-naive, short-illness-duration, and treatment-response patients with major depressive disorder: A resting-state fMRI study

Background: Abnormality of limbic-cortical networks was postulated in depression. Using a regional homogeneity (ReHo) approach, we explored the regional homogeneity (ReHo) of the brain regions in patients with first-episode, treatment-naive, short-illness-duration, and treatment-response depression in resting state to test the abnormality hypothesis of limbic-cortical networks in major depressive disorder (MDD). Methods: Seventeen patients with treatment-response MOD and 17 gender-, age-, and education-matched healthy subjects participated in the resting-state fMRI scans. Results: 1. The MDD group showed a significant lower ReHo in the left cerebellum posterior lobe, the right fusiform gyrus, the left parahippocampal gyrus, and the right postcentral gyrus compared with healthy subjects (p < 0.05, corrected). 2. Relative to healthy subjects, a significant higher ReHo was found in the right inferior temporal gyrus in the MDD group (p < 0.05, corrected). Conclusions: Our findings suggested the abnormality of limbic-cortical networks in first-episode, treatment-naive, short-illness-duration, and treatment-response MDD patients, and added an expanding literature to the abnormality hypothesis of limbic-cortical networks in MDD. (C) 2011 Elsevier B.V. All rights reserved.