fMRI evidence for abnormal resting-state functional connectivity in euthymic bipolar patients

Area of Science:

• Neuroscience
• Psychiatry
• Brain Imaging

Background:

• Bipolar disorder (BD) is linked to fronto-limbic network dysregulation, potentially persisting in euthymic states.
• Few studies explore resting-state functional connectivity in euthymic bipolar patients (BP).
• Identifying trait abnormalities in euthymic BP is crucial for understanding persistent mood dysregulation.

Purpose of the Study:

• To assess resting-state functional connectivity in euthymic bipolar patients (BP).
• To identify trait abnormalities underlying mood dysregulation in euthymic BP.
• To investigate medial prefrontal cortex (mPFC) functional connectivity patterns.

Main Methods:

• Investigated mPFC functional connectivity in 20 euthymic BP and 20 healthy subjects (HS).
• Compared functional connectivity maps using between-group random effect analysis.
• Conducted region of interest (ROI) analysis on mPFC-amygdala connectivity and clinical correlations.

Main Results:

• Euthymic BP showed altered mPFC connectivity compared to HS.
• BP group exhibited decreased mPFC-dlPFC connectivity and increased mPFC-amygdala connectivity.
• Increased mPFC-amygdala connectivity correlated with disease duration in BP.

Conclusions:

• Euthymic BP display abnormal decoupling between mPFC-dlPFC and hyperconnectivity between mPFC-amygdala.
• These connectivity alterations may contribute to BD pathophysiology.
• Findings suggest that these abnormalities could worsen with disease progression.