Abnormalcerebral-limbic functional connectivity between bipolar mania and bipolar depression under resting state

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Aberrant functional connectivity (FC) is noted in bipolar disorder (BD).
• The specificity of FC patterns to bipolar mania (BD-M) and bipolar depression (BD-D) is unclear.
• Understanding these differences is crucial for diagnosing and treating mood states in BD.

Purpose of the Study:

• To compare cerebral-limbic FC patterns between BD-M, BD-D, and healthy controls (HC).
• To investigate the relationship between FC abnormalities and depressive symptom severity.

Main Methods:

• Resting-state functional magnetic resonance imaging (fMRI) was used.
• 30 BD-M patients, 31 BD-D patients, and 30 HC subjects were included.
• Interregional cerebral FC values were calculated and compared between groups.

Main Results:

• Exploratory analysis (p<0.001, uncorrected) revealed abnormal cerebral-limbic FC in both BD-M and BD-D groups.
• BD-D showed elevated FC in default mode network (DMN), attention, and limbic areas.
• BD-M displayed reduced cerebral-limbic FC in the DMN and limbic regions.

Conclusions:

• Distinct cerebral-limbic FC patterns differentiate BD-M and BD-D.
• BD-M is associated with reduced DMN FC, while BD-D shows increased DMN FC.
• These findings suggest potential neurofunctional correlates of mood states in bipolar disorder, requiring further validation.