Tract-based structural and functional connectivity abnormalities in bipolar I disorder.

Area of Science:

• Neuroimaging
• Psychiatry
• Neurology

Background:

• Bipolar disorder (BP) presents complex neural underpinnings.
• Understanding white matter (WM) tract abnormalities is crucial for BP research.

Purpose of the Study:

• Investigate structural and functional connectivity (FC) abnormalities in WM tracts in bipolar disorder (BP).
• Identify specific WM tracts affected in BP subtype I (BP-I).

Main Methods:

• Utilized diffusion MRI and resting-state functional MRI data from 56 BP-I patients and 40 healthy controls (HCs).
• Segmented 72 WM tracts and calculated mean diffusivity (MD) and fractional anisotropy (FA) for structural connectivity.
• Assessed functional connectivity (FC) between tract regions and used ANCOVA for group comparisons.

Main Results:

• BP-I patients exhibited lower FA in the corpus callosum, cingulum, and superior longitudinal fasciculus III (SLF-III).
• BP-I patients showed higher MD in the corpus callosum and commissure anterior.
• Significantly lower FC was observed in the right SLF-III of BP-I patients compared to HCs.

Conclusions:

• Bipolar disorder (BP-I) is associated with altered structural connectivity and FC in specific WM tracts.
• Findings provide insights into the pathophysiology of bipolar disorder.
• Further research is needed for diagnostic and therapeutic implications.