Abstract

BACKGROUND:

Previous structural imaging studies found evidence of brain morphometric changes in major depression (MD) patients, but they rarely excluded compounding effects of some important factors, such as medication and brain degeneration. This study sought to explore the brain morphometric changes of first-episode, drug-naïve, non-late-life adult MD patients with optimized voxel-based morphometry (VBM) method.

METHODS:

Twenty-three first-episode, drug-naïve, non-late-life adult depressed patients and 23 healthy control subjects were enrolled in this study. Subjects underwent high-resolution magnetic resonance imaging, and optimized VBM was performed to analyze the morphometric data. A partial correlation model was used to analyze associations of morphometric changes with Hamilton Depression Rating Scale scores and illness duration.

RESULTS:

Depressed patients showed significant gray matter volume reduction in the bilateral limbic system, especially in hippocampus. These changes did not significantly correlate with symptom severity or illness duration.

CONCLUSIONS:

Our findings provided new evidence of gray matter deficits in first-episode, drug-naïve, non-late-life adult MD patients. It supported that the reduction of hippocampal volume is a trait for MD patients and further highlighted the important role of the limbic system, particularly hippocampus in the pathophysiology of MD.