For the first time, a team of researchers at the Keck School of Medicine at the University of Southern California conducted a known comparison of the brains of boys and girls with binge eating disorder, finding significant differences
in brain structure between the sexes.
The study was recently published in
the journal Psychological Medicine.
The study builds on earlier research showing that binge eating disorder is ingrained in the brain at an early age, an important first step
in understanding the neurobiology of binge eating disorder and how it differs between sexes.
It also provides important evidence that men who have been excluded from past studies of eating disorders must be included in future efforts to understand the origins of eating disorders
"Men have been excluded from eating disorders for decades," said
Stuart Murray, Ph.
of DClin Psych and Associate Professor of Psychiatry and Behavioral Sciences at the Keck School of Medicine at the University of Southern California.
He noted that this exclusion is long-standing due to eating disorders that are thought to be uncommon in men
"By excluding boys and men, we only developed treatments from studying women, and then we applied it to boys and men and hoped they had the same effect
However, it has become increasingly clear in recent years that some eating disorders are actually almost as common
among men and boys as they are among women and girls.
At the same time, research has found growing evidence that eating disorders are the result
of brain disorders rather than social stress or a lack of willpower.
Murray said these are common misconceptions that have been proven wrong
Same disease, different brain structure
Using data from the Adolescent Brain Cognitive Development Study, the largest brain development assessment study in the United States, the researchers identified 38 boys and 33 girls from the study's 11,875 participants who were diagnosed with binge eating disorder
Among children, boys account for 57%
of people with binge eating disorder.
This number varies among adults, who make up about 43 percent
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 through voxel-based morphometry, a neuroimaging technique that allowed the researchers to examine differences
in the anatomy of the entire brain structure.
The study showed that girls with binge eating disorder had elevated
gray matter density in several parts of the brain associated with impulse control and binge eating disorder symptoms compared to 74 control children matched in age, body mass index, and developmental maturity.
However, boys with binge eating disorder did not have elevated
gray matter density in these areas.
The increased gray matter density in girls with binge eating disorder suggests that a key process of brain maturation — synaptic pruning — may have undergone unique alterations or delays
in these girls.
"This study clearly shows that any neurobiological hypothesis about binge eating disorder needs to be stratified
by sex," Murray said.
Include males that are critical for future treatment
Similarly, the fact that boys and girls with binge eating disorder (binge eating disorder is the most common type of eating disorder) have different brain structures suggests that men may need a different type of
treatment than women.
Murray added that new treatments for binge eating disorder are on the horizon, including transcranial magnetic stimulation and direct current stimulation, both of which target the brain
As with previous studies on eating disorders, so far the study has only included female subjects
"The difference in brain structure between boys and girls with binge eating disorder means that any treatment that targets the brain must be tested in both men and women," Murray said
"Otherwise, we're targeting parts of the male brain that aren't necessarily abnormal
Next, Murray and his team will test to see if the brains of men and women with binge eating disorder function
differently than structurally different.