International Study Links Bulimia Nervosa to Localized Brain Structural Differences

An ENIGMA Eating Disorders Working Group case-control study examined structural brain correlates of bulimia nervosa using MRI and clinical data from 13 international sites encompassing 17 cohorts. Prospective meta-analyses compared cortical thickness, cortical surface area, and subcortical volumes in 369 participants with bulimia nervosa and 417 healthy controls. All participants were female; mean age was 23.6 years, with a range of 12.0–53.6 years. Imaging underwent standardized preprocessing and quality control.

Compared with controls, participants with bulimia nervosa had lower nucleus accumbens volume (Cohen d, −0.20; 95% CI, −0.34 to −0.06), superior temporal cortical surface area (d, −0.26; 95% CI, −0.41 to −0.12), and transverse temporal cortical surface area (d, −0.24; 95% CI, −0.38 to −0.10). Cortical thickness did not differ significantly. Most differences persisted after accounting for cohort-level variation in body mass index, illness duration, depressive symptoms, psychotropic medication use, and purging.

Greater binge-eating frequency correlated with lower surface area in several cortical regions, with correlations ranging from −0.20 to −0.14. No anatomical measures were associated with total compensatory behaviors. These modest associations support further investigation of circuits involved in reward, cognitive control, interoception, and social cognition, but do not establish causality or clinical diagnostic utility. The all-female sample limits generalizability; this update is based on the abstract, without access to the full text.