Structural brain differences in major depressive disorder patients with suicidal risk: Evidence from the DIRECT...

Area of Science:

• Neuroimaging
• Psychiatry
• Neuroscience

Background:

• Structural brain alterations are observed in major depressive disorder (MDD) patients, but consensus on suicide risk-related differences is lacking.
• Understanding neurophysiological mechanisms of suicide risk in MDD is crucial for developing targeted interventions.

Purpose of the Study:

• To investigate structural brain differences between MDD patients with and without suicide risk using DIRECT Consortium data.
• To identify potential neuroimaging biomarkers for suicide risk in MDD.

Main Methods:

• Included 203 healthy controls (HCs), 208 MDD patients without suicide risk (MDD-NSR), and 376 MDD patients with suicide risk (MDD-SR).
• Utilized T1-weighted MRI data processed with DPABISurf to quantify cortical surface area, thickness, and cortical gray matter (CGM) volume.

Main Results:

• MDD-SR and MDD-NSR groups showed reduced surface area in the right orbitofrontal cortex (OFC) and reduced CGM volume in the left anterior cingulate cortex (ACC) and right OFC compared to HCs.
• A significant gradient of decreasing left ACC CGM volume was observed: MDD-SR < MDD-NSR < HC.
• Support Vector Machine (SVM) analysis showed limited differentiation, but SHAP analysis identified left ACC CGM volume as a critical feature for suicide risk.

Conclusions:

• MDD patients with suicide risk exhibit distinct frontal lobe structural alterations, including reduced cortical surface area and CGM volume.
• Reduced left ACC CGM volume may serve as a potential neuroimaging biomarker for predicting suicide risk in MDD patients.