Left Cerebral Cortex Complexity in Patients with Major Depression Disorder: A Small-Sample Pilot Study

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Major Depressive Disorder (MDD) is a prevalent mental health condition.
• Early-stage, drug-naive MDD may exhibit distinct neurobiological markers.
• Cerebral cortical complexity (CCC) is a measure of cortical folding and surface irregularity.

Purpose of the Study:

• To investigate cerebral cortical complexity (CCC) in patients with first-episode, drug-naive major depressive disorder (MDD).
• To analyze alterations in gyrification index (GI) and fractal dimension (FD) using source-based morphometry (SBM).
• To correlate CCC alterations with depression symptom severity.

Main Methods:

• 14 first-episode, drug-naive MDD patients and healthy controls (HCs) were analyzed.
• Source-based morphometry (SBM) was used to assess CCC via gyrification index (GI) and fractal dimension (FD).
• The Hamilton Depression Scale (HAMD-17) assessed depression severity.

Main Results:

• Increased GI was observed in the left postcentral gyrus of MDD patients compared to HCs.
• Decreased GI was found in the left angular, lingual, superior temporal, and insular cortices.
• Altered FD was noted in the superior frontal and left superior temporal gyri, with both increases and decreases observed.

Conclusions:

• A trend of altered left-hemisphere CCC was observed in first-episode, drug-naive MDD patients.
• Findings suggest subtle neocortical aberrations in early-stage MDD.
• While not statistically significant after FWE correction, the results indicate potential early neurobiological changes.