Fronto-limbic disconnection in depressed patients with suicidal ideation: A resting-state functional connectivity...

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Suicidal ideation (SI) is a common symptom of Major Depressive Disorder (MDD), yet its biological basis remains unclear.
• Existing research suggests links between SI and impaired fronto-limbic brain circuits.
• Investigating these neural connections is crucial for understanding MDD pathophysiology.

Purpose of the Study:

• To examine fronto-limbic disconnection in individuals with MDD, differentiating between those with and without SI.
• To compare neural activity patterns in the rostral anterior cingulate cortex (rACC) across patient groups and healthy controls.

Main Methods:

• Resting-state functional MRI (fMRI) was used to analyze intrinsic functional connectivity (iFC) in three groups: MDD with SI (n=28), MDD without SI (NSI, n=20), and healthy controls (HCs, n=30).
• fMRI data focused on the rACC and its connections with other brain regions.
• Correlation analyses examined relationships between iFC, SI severity, and depression severity.

Main Results:

• The SI group displayed reduced iFC between the rACC and the orbitomedial prefrontal cortex/right middle temporal pole compared to HCs and NSI groups.
• The NSI group showed decreased rACC-orbitomedial prefrontal cortex iFC relative to HCs.
• In the SI group, stronger rACC-middle temporal pole iFC correlated with greater SI severity.

Conclusions:

• The study identified both transdiagnostic and diagnosis-specific alterations in fronto-limbic iFC in MDD patients with and without SI.
• Disruptions in these fronto-limbic circuits may impair decision-making and emotional regulation in individuals with SI.
• These findings offer valuable insights into the pathophysiological mechanisms underlying suicidal ideation in MDD.