Differential brain regional activity and connectivity of anterior cingulate cortex between major depressive disorder...

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Major depressive disorder (MDD) is a significant risk factor for suicide.
• Suicidal ideation (SI) is a precursor to suicidal behavior.
• The neural underpinnings of SI in MDD remain largely unknown.

Purpose of the Study:

• To investigate the neural mechanisms associated with suicidal ideation (SI) in major depressive disorder (MDD).
• To compare brain activity and connectivity patterns between MDD patients with and without SI, and healthy controls.
• To explore the relationship between neural alterations and the severity of suicidal ideation.

Main Methods:

• Utilized functional neuroimaging techniques including amplitude of low-frequency fluctuations (ALFF), functional connectivity (FC), and effective connectivity (EC).
• Compared brain imaging data across three groups: MDD with SI (MDD-SI), MDD without SI (MDD-NSI), and healthy controls (HCs).
• Validated ALFF findings using a large consortium dataset and analyzed the correlation between neural metrics and SI severity.

Main Results:

• MDD-SI patients exhibited increased ALFF in the right anterior cingulate cortex (ACC) compared to MDD-NSI.
• Reduced FC was observed between the right ACC and left inferior frontal gyrus in MDD-SI.
• Altered EC patterns involving the ACC were identified, showing a progressive increase from HCs to MDD-NSI to MDD-SI, correlating with suicidal behavior severity.

Conclusions:

• The anterior cingulate cortex (ACC) shows heightened activity and aberrant connectivity in MDD patients experiencing SI.
• These neural alterations in the ACC may serve as potential biomarkers for assessing suicide risk in MDD.