Bipolar disorder: Functional neuroimaging markers in relatives

Area of Science:

• Neuroscience
• Psychiatry
• Brain Imaging

Background:

• Neural models of bipolar disorder (BD) are limited by confounding factors in affected patients.
• Studying high-risk individuals, such as first-degree relatives, can identify liability markers for BD.
• Functional magnetic resonance imaging (fMRI) is a key tool for investigating neural alterations.

Purpose of the Study:

• To systematically review and summarize fMRI studies on first-degree relatives of BD patients.
• To identify neural correlates associated with the risk of developing BD.
• To compare findings in high-risk individuals with those reported in BD patients.

Main Methods:

• Systematic literature search for fMRI studies on first-degree relatives of BD patients.
• Analysis of studies examining working memory, emotional processing, executive functions, and resting-state networks.
• Comparison of neural findings in relatives versus healthy controls.

Main Results:

• Twenty-nine fMRI studies were included, focusing on various cognitive and emotional tasks.
• Relatives of BD patients exhibited altered neural activity in regions like the inferior frontal gyrus and limbic areas.
• These altered regions overlap with those implicated in the pathophysiology of BD.

Conclusions:

• Brain regions such as the amygdala, implicated in BD pathophysiology, are also associated with BD risk.
• Functional alterations in high-risk individuals mirror those seen in diagnosed BD patients.
• Longitudinal studies are necessary to confirm the role of these neural markers in BD onset.