Advances from neuroimaging studies in eating disorders

Area of Science:

• Neuroscience
• Psychiatry
• Radiology

Background:

• Eating disorders are complex mental illnesses with significant neurological underpinnings.
• Previous brain imaging studies yielded inconsistent findings due to confounding factors like starvation and medication.

Purpose of the Study:

• To review and synthesize recent brain imaging findings in eating disorders.
• To elucidate the role of gray matter, white matter, and functional connectivity in anorexia nervosa and bulimia nervosa.

Main Methods:

• Systematic review of neuroimaging studies (MRI, fMRI) in individuals with anorexia nervosa and bulimia nervosa.
• Analysis of gray matter and white matter volumes, and functional activity in response to taste and reward stimuli.

Main Results:

• Enlarged left medial orbitofrontal gyrus rectus volume observed in recovered anorexia nervosa and in bulimia nervosa.
• Enlarged right insula in ill and recovered anorexia nervosa, potentially linked to altered interoception and body perception.
• Reduced fornix integrity (white matter) consistently found in anorexia nervosa and bulimia nervosa.
• Altered dopamine-related reward pathway activity: hypersensitive in anorexia nervosa, hyporesponsive in bulimia nervosa and obesity.

Conclusions:

• Brain imaging studies increasingly define specific neural circuitry alterations in eating disorders.
• Structural and functional changes in the orbitofrontal cortex, insula, and reward pathways suggest adaptive, yet maladaptive, responses to extreme eating behaviors.
• These neurobiological changes may impede the normalization of eating patterns and warrant further investigation.