Gray matter volume covariance networks are associated with altered emotional processing in bipolar disorder: a...

Area of Science:

• Neuroimaging
• Psychiatry
• Brain Structure

Background:

• Bipolar disorder (BD) is characterized by widespread gray matter volume (GMV) alterations.
• Structural brain networks, reflecting complex brain organization, and their functional correlates remain understudied in BD.

Purpose of the Study:

• To investigate structural brain networks and their relationship with clinical and psychological functions in bipolar disorder type-I (BD-I) and type-II (BD-II).
• To identify neuroanatomical differences associated with BD subtypes and their impact on cognitive and emotional processing.

Main Methods:

• Magnetic Resonance Imaging (MRI) scans were acquired from 24 BD-I patients, 30 BD-II patients, and 45 healthy controls.
• Voxel-based morphometry and source-based morphometry (SBM) were employed to analyze GMV patterns and structural covariation.
• Comparisons of SBM components were made across diagnostic groups, correlating findings with executive function and emotional processing.

Main Results:

• BD-I patients exhibited reduced GMV in temporo-insular-parieto-occipital cortex and culmen compared to controls.
• A prefrontal-temporal-occipital network showed significantly lower GMV in BD-I versus controls, associated with manic episodes and executive dysfunction.
• BD-I showed greater GMV loss in temporal-occipital regions compared to BD-II, correlating with impaired emotional processing.

Conclusions:

• Altered prefrontal-temporal-occipital network structure may represent a neural signature in BD-I.
• These structural changes are linked to visuospatial, problem-solving, and emotional processing deficits, as well as illness severity in BD-I.