Researchers at the Icahn School of Medicine at Mount Sinai analyzed MRI brain scans from 369 female participants with bulimia nervosa and 417 female participants without an eating disorder. Published in JAMA Psychiatry, the 2026 study reveals that more frequent binge eating links to widespread structural differences across brain regions governing reward, emotion, and bodily awareness.
For decades, medical science has categorized bulimia nervosa largely by the frequency of its observable symptoms—specifically, the cycle of recurrent binge eating paired with inappropriate compensatory behaviors. Yet, the underlying neurobiology of the condition has remained opaque, hindered by small past neuroimaging cohorts and inconsistent findings. That picture shifted significantly with a major international study published in JAMA Psychiatry.
Icahn School of Medicine at Mount Sinai
Led by investigators at the Icahn School of Medicine at Mount Sinai, a research team from the global ENIGMA consortium sought to map the physical brain structures associated with the illness. By pulling together MRI brain scans from 17 international cohorts, the team assembled a cohort of 369 female participants diagnosed with bulimia nervosa and compared them against 417 female participants without an eating disorder.
The collaborative analysis uncovered distinct structural variations that separate individuals with bulimia nervosa from populations without an eating disorder. According to the findings, patients with the disorder exhibited lower volume in the nucleus accumbens, a brain region involved in processing reward and motivation. Furthermore, the scans revealed lower surface area within regions of the temporal cortex, a brain area dedicated to sensory and social processing.
These discoveries offer the clearest evidence to date regarding the physical brain correlates of the disorder. Laura A. Berner, Ph.D., director of the Center for Computational Psychiatry at Mount Sinai and lead author of the study, expressed astonishment at where some of these anatomical variations appeared.
This study gives us the clearest evidence to date that bulimia nervosa is associated with reproducible differences in brain structure. We were surprised that the differences we identified in the brain’s outer layer involved a structural feature that is largely established early in development.
Laura A. Berner, Ph.D., director of the Center for Computational Psychiatry at Mount Sinai
ENIGMA consortium
A critical nuance of the Mount Sinai-led research lies in how specific symptoms correlate with neuroanatomy, rather than viewing the illness as a monolithic block. The data demonstrated that more frequent binge eating episodes track directly onto broader, more widespread structural differences in the brain’s outer layer.
Specifically, patients who experienced more frequent binge eating showed lower surface area across additional brain regions responsible for cognitive control, reward value estimation, the awareness of bodily signals, and the processing and regulation of emotions. In a striking divergence from traditional clinical assumptions, the frequency of compensatory behaviors—the measure currently used to define bulimia nervosa severity—showed no association with these brain structures whatsoever. This disconnect suggests that individual symptoms, particularly binge eating, possess distinct neurobiological correlates.
Albert J. Stunkard
The new neuroimaging insights arrive against a backdrop of evolving clinical definitions for eating disorders involving binge behaviors. Binge-eating disorder itself was officially incorporated into the Diagnostic and Statistical Manual of Mental Disorders (DSM) in 2013 and the International Classification of Diseases (ICD) in 2019. The core psychopathology across conditions like bulimia nervosa and binge-eating disorder involves consuming comparably large amounts of food within a discrete timeframe while experiencing loss of control.
Historically, the study of binge eating stretches back to the late 1950s, attributed to American psychiatrist Albert J. Stunkard, alongside fellow psychiatrist Walter W. Hamburger, who laid the foundation for the understanding that obesity entails also emotional aspects. While early notions treated binge eating primarily as a behavior, subsequent revisions integrated it into complex psychiatric classifications. Unlike bulimia nervosa—which requires regular inappropriate compensatory methods such as self-induced vomiting, fasting, or laxative misuse to prevent weight gain—disorders like BED do not regularly compensate using inappropriate methods, yet both conditions grapple with the core challenge of recurrent binge eating.
Laura A. Berner
Because the new ENIGMA consortium study captured participants at a single point in time, researchers emphasize that longitudinal investigations are vital to determining whether these differences precede or follow illness onset. Experts must still determine whether lower nucleus accumbens volume and altered temporal cortex surface area could be markers of vulnerability to developing the illness, or whether they emerge as a consequence of the disease.
At the same time, study authors caution against fatalistic interpretations of neuroimaging data. The identified variations do not imply that the brain is fixed or that an individual’s outcome is predetermined. Instead, the research opens pathways toward exploring how these anatomical differences alter the function of affected brain circuits, ultimately aiding researchers in pinpointing better targets for future prevention and treatment strategies.