Structural Brain Correlates of Bulimia Nervosa Diagnosis and Symptom Severity: A Coordinated ENIGMA Eating Disorders Working Group Analysis.
Laura A Berner, Anusha Phadnis, Margaret L Westwater et al.
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In 30 seconds
This coordinated, international case-control meta-analysis examined structural MRI correlates of bulimia nervosa (BN) diagnosis and symptom severity across 17 cohorts at 13 sites. The sample comprised 369 females with BN and 417 healthy female controls. Compared with controls, participants with BN had lower nucleus accumbens volume (Cohen d, -0.20; 95% CI, -0.34 to -0.06) and lower surface area in the superior and transverse temporal cortices; cortical thickness did not differ significantly. Greater binge-eating frequency was associated with lower surface area in several regions, whereas total compensatory behaviors were not associated with anatomical measures.
Key findings
- BN was associated with lower nucleus accumbens volume (Cohen d, -0.20; 95% CI, -0.34 to -0.06).
- Cortical surface area was lower in the superior temporal (d, -0.26; 95% CI, -0.41 to -0.12) and transverse temporal cortices (d, -0.24; 95% CI, -0.38 to -0.10) in BN.
- Binge-eating frequency correlated with lower surface area across several regions (r value range, -0.20 to -0.14), but not with cortical thickness or subcortical volume.
- No anatomical characteristics were associated with total compensatory behaviors; no significant group differences in cortical thickness were observed.
Why it matters
The findings identify modest, localized structural differences associated with BN and binge-eating frequency across a large, coordinated international sample. Their distribution is consistent with involvement of reward, cognitive control, interoceptive, and social cognition circuits, offering evidence to inform neurobiological models of a disorder whose brain basis remains poorly characterized.
What to keep in mind
The case-control design identifies associations and cannot establish that the structural differences cause BN or its symptoms. All participants were female, limiting generalizability to males.