Structural correlates of trait impulsivity in patients with bipolar disorder and healthy controls: a surface-based...

Area of Science:

• Neuroscience
• Psychiatry
• Brain Imaging

Background:

• Trait impulsivity is a key biomarker in bipolar disorder (BD), often present regardless of mood state.
• Understanding the structural brain correlates of impulsivity is crucial for BD research.

Purpose of the Study:

• To investigate the association between trait impulsivity (Barratt Impulsiveness Scale - BIS) and cortical thickness in patients with BD and healthy controls (HCs).

Main Methods:

• Structural magnetic resonance imaging (MRI) was used to measure cortical thickness in 59 BD patients and 56 HCs.
• An automated surface-based method (FreeSurfer) generated cortical thickness maps.
• Brain-wise regression analysis examined the relationship between BIS scores and cortical thickness in both groups.

Main Results:

• BD patients had significantly higher BIS scores than HCs.
• In HCs, higher BIS scores correlated with thinner left frontal cortices.
• In BD patients, higher BIS scores correlated with a thicker right insula; BD patients showed thinner cortices overall in these regions compared to HCs.

Conclusions:

• The left prefrontal cortex is critical for trait impulsivity in healthy individuals.
• The right insula represents a distinct structural correlate of trait impulsivity in BD patients.
• Psychotropic medication use in BD patients may influence findings, warranting cautious interpretation.