Increased anterior default-mode network homogeneity in first-episode, drug-naive major depressive disorder: A replication study

J Affect Disord. 2018 Jan 1:225:767-772. doi: 10.1016/j.jad.2017.08.089. Epub 2017 Sep 12.

Abstract

Background: Abnormal default-mode network (DMN) homogeneity has been involved in the neurophysiology of major depressive disorder (MDD) with inconsistent findings. The inconsistency may be due to clinical and methodological variability, and the reproducibility of the findings is limited. The present study aimed to examine alterations of the DMN homogeneity in two independent samples of patients with first-episode, drug-naive MDD.

Methods: The samples included 59 patients with MDD and 31 comparison subjects from Sample 1 and 29 patients with MDD and 24 comparison subjects from Sample 2. Network homogeneity (NH) was computed with an overlapping technique, which was employed to define brain regions with abnormal NH common to the MDD samples.

Results: Compared with comparison subjects, patients with MDD exhibited increased NH in an overlapped brain region of the left superior medial prefrontal cortex (MPFC). No correlations were found between abnormal NH and HAMD total/subscale scores in the patients of each sample and in the combined patients from both samples.

Conclusions: This study is the first to examine alterations of DMN homogeneity in first-episode, drug-naive patients with MDD in two independent samples by using an overlapping technique. Patients with MDD exhibit increased NH in an overlapped region in the anterior DMN. The present study thus highlights the importance of the DMN in the neurophysiology of MDD.

Keywords: Default-mode network; Functional magnetic resonance imaging; Major depressive disorder; Network homogeneity.

MeSH terms

  • Adult
  • Brain / physiopathology
  • Depressive Disorder, Major / physiopathology*
  • Female
  • Functional Neuroimaging
  • Humans
  • Magnetic Resonance Imaging / methods
  • Male
  • Middle Aged
  • Neural Pathways / physiopathology*
  • Prefrontal Cortex / pathology*
  • Rest / physiology
  • Rest / psychology*