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

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Default-mode network (DMN) homogeneity alterations are implicated in major depressive disorder (MDD) but findings are inconsistent.
• Clinical and methodological variability may explain inconsistent findings and limited reproducibility.
• This study investigates DMN homogeneity in first-episode, drug-naive MDD patients.

Purpose of the Study:

• To examine alterations in DMN homogeneity in two independent samples of first-episode, drug-naive MDD patients.
• To identify brain regions with abnormal DMN homogeneity common to MDD patients.
• To explore the neurophysiological underpinnings of MDD.

Main Methods:

• Two independent samples of MDD patients and comparison subjects were analyzed.
• Network homogeneity (NH) was computed using an overlapping technique.
• Abnormal NH regions common to both MDD samples were identified.

Main Results:

• MDD patients showed increased NH in the left superior medial prefrontal cortex (MPFC) compared to controls.
• This increased NH was observed in an overlapped brain region common to both samples.
• No significant correlations were found between abnormal NH and HAMD scores.

Conclusions:

• This is the first study to examine DMN homogeneity in first-episode, drug-naive MDD using two independent samples and an overlapping technique.
• Increased NH in an anterior DMN region was observed in MDD patients.
• The findings underscore the DMN's significance in MDD neurophysiology.