Research reveals key differences in the brains of boys and girls with binge eating

By conducting the first known comparison of the brains of boys and girls with binge eating, a team of researchers from USC’s Keck School of Medicine discovered significant differences in brain structure between the sexes. The research was recently published in Psychological medicine.

The study, which builds on previous work suggesting that binge eating is hardwired into the brain from an early age, is an important first step in understanding the neurobiology of binge eating and how it differs between the sexes. It also presents critical evidence that men, who in the past have been excluded from eating disorder research, need to be included in future efforts to understand the origins of eating disorders.

“Men have been excluded from eating disorder research for decades,” said Stuart Murray, DClinPsych, Ph.D., Della Martin Associate Professor of Psychiatry and Behavioral Sciences at Keck School of Medicine. from USC, noting that the exclusion has been perpetuated. by the belief that it was rare for men to have eating disorders. “Because of the exclusion of boys and men, we have developed treatments only from the study of women, which we then apply to boys and men and hope that they work with the same effectiveness.”

However, it has become increasingly clear in recent years that certain eating disorders are in fact almost as prevalent in men and boys as in women and girls. At the same time, research has found growing evidence that eating disorders are diseases of the brain and not the result of social pressure or a lack of willpower, which Murray says are common misconceptions that have been debunked.

Same disease, different brain structure

Using data from the Adolescent Brain Cognitive Development Study, the largest study in the United States assessing brain development, researchers identified 38 boys and 33 girls who had been diagnosed with binge eating disorder among 11,875 study participants. Among children, boys make up about 57% of people with binge eating disorder. This figure changes in adults, with adult men accounting for about 43% of people with binge eating disorder.

The research team was able to assess the density of gray matter in the brains of the 9- and 10-year-old children in the study, via voxel-based morphometrics, a neuroimaging technique that allows researchers to examine differences in structural anatomy of the brain in the whole study. brain. It showed that, compared to a control group of 74 children matched on age, body mass index and developmental maturation, girls with binge eating had elevated gray matter density in several parts of the brain. known to be related to impulse control and binge eating. eating disorder symptoms. However, boys with binge eating did not have high gray matter density in these areas. This high gray matter density in girls with binge eating suggests that a crucial brain maturation process – synaptic pruning – may be uniquely impaired or delayed in these girls.

“This study clearly suggests that any neurobiological hypothesis of binge eating must be stratified by sex,” Murray said.

The inclusion of men is essential for future treatments

Similarly, the fact that boys and girls with binge eating disorder, which is the most common type of eating disorder, have different brain structures indicates that men may require different types of treatment than women. women.

Murray added that new treatments for binge eating are on the horizon and include transcranial magnetic stimulation and direct current stimulation, both of which target the brain directly. As with previous research on eating disorders, so far only female subjects have been included in the research.

“The differences in brain structure between boys and girls with binge eating disorder mean that any treatment targeting the brain must be tested on men as well as women,” Murray said. “Otherwise we would be targeting parts of the brain in men that are not necessarily abnormal.”

Next, Murray and his team will run tests to see if, in addition to having different structures, the brains of men and women with binge eating function differently.

Other study authors include Christina J. Duval, Anne A. Balkchyan, Darrin J. Lee, Steven J. Siegel, Arthur W. Toga, and Kay Jann of USC’s Keck School of Medicine; Joel P. Diaz-Fong of UCLA; Jason M. Nagata of UCSF; and Kyle T. Ganson of the University of Toronto.