Anorexia's Unique Fingerprint on the Brain Revealed by Novel Scans

Is it anorexia nervosa itself, or the resulting low body weight, that alters the brain's structure? A new study offers a clearer picture by comparing MRI scans from three groups of females: those with acute anorexia, healthy individuals with a similarly low BMI, and healthy individuals with a normal BMI.

The findings suggest anorexia has a distinct signature. Compared to the underweight healthy group, patients with anorexia exhibited volume reductions in deep brain regions like the pallidum and caudate, alongside thinning of the cortex — the brain's outer layer — in key areas of the 'default mode network'.

Conversely, some brain changes, like reduced volume in the amygdala, were seen in both underweight groups, suggesting these are related to low body weight rather than the disorder. Furthermore, within the anorexia group, a history of greater weight loss (known as weight suppression) was linked to more widespread cortical thinning, pointing to the lasting impact of the illness's course. This research provides a crucial foundation for distinguishing the effects of the disease from the effects of malnourishment.