Dissecting the Causal Association Between Bulimia Nervosa and Structural Brain Abnormalities: A Two-Sample...

Area of Science:

• Neuroimaging
• Psychiatry
• Genetics

Background:

• Previous studies show correlations between brain abnormalities and bulimia nervosa (BN).
• Understanding the causal relationship between BN and brain structure is crucial.

Purpose of the Study:

• To investigate the bidirectional causality between bulimia nervosa (BN) and brain structural magnetic resonance imaging (MRI) phenotypes.
• To explore genetic predispositions for BN and their relationship with brain structure.

Main Methods:

• Utilized genome-wide association studies (GWAS) to identify genetic variants for disordered eating and BN prediction.
• Employed a bidirectional two-sample Mendelian randomization (MR) approach using UK Biobank 3D-T1 MRI data to analyze brain structural phenotypes.
• Examined causal relationships between BN and specific brain structural traits.

Main Results:

• Bulimia nervosa (BN) causally influenced decreased left nucleus accumbens volume and left inferior temporal gyrus surface area (SA).
• BN also led to increased cortical thickness (CT) in the left planum temporale and right inferior temporal gyrus.
• Reverse MR analysis revealed associations between specific brain structures (e.g., right putamen volume, left hippocampus volume) and BN risk, with some brain SA and CT inversely correlated with BN risk.

Conclusions:

• Confirmed potential causal effects of BN on brain structure changes across multiple functional regions.
• Identified that genetically determined variations in specific brain structural regions can be causal for BN.
• The findings suggest a complex interplay between BN and brain structural phenotypes.