Resting-State Functional Connectivity and Brain Network Abnormalities in Depressive Patients with Suicidal Ideation

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Depressive disorders are a significant global health concern.
• Suicidal ideation within depression requires objective biomarkers for understanding and treatment.
• Functional magnetic resonance imaging (fMRI) offers insights into brain function.

Purpose of the Study:

• To investigate detectable changes in brain function using fMRI in individuals with depressive disorders and suicidal ideation.
• To explore the association between depression severity and brain imaging metrics.
• To compare brain network topology between healthy controls and depressed individuals with suicidal ideation.

Main Methods:

• Recruited 111 participants: 35 with suicidal ideation (SI), 32 without (NS), and 44 healthy controls (HCs).
• Acquired resting-state 3T MRI scans.
• Analyzed functional connectivity (FC), amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo), and graph theoretical analysis (GTA).

Main Results:

• Identified functional activity differences in the hippocampus and thalamus between SI and NS groups.
• Observed lower activity in the thalamus and cuneus regions associated with suicidal ideation.
• Found correlations between brain functional connectivity (hippocampus, cuneus, frontal regions) and depression/anxiety scales (HAM-D, HADS) in the SI group.
• GTA revealed altered brain network organization and local segregation in the SI group compared to HCs.

Conclusions:

• Brain functional activity and connectivity are altered in depressive patients experiencing suicidal ideation.
• Specific brain regions like the thalamus and cuneus show reduced activity linked to suicidal thoughts.
• fMRI metrics demonstrate potential as objective indicators for depression severity and suicidal ideation.