Binge eating disorder may have genetic ties

Researchers at Harvard-affiliated McLean Hospital have reported that binge eating disorder runs in families, raising the possibility that this condition may have a genetic basis.

In the study, published in the March 6, 2006 issue of the Archives of General Psychiatry, the researchers found that family members of obese individuals with binge eating disorder were twice as likely to suffer from the condition as were family members of obese individuals who did not have a history of binge eating. “This indicates that there may be a genetic component to binge eating disorder,” said lead author James I. Hudson, MD, ScD, director of the Biological Psychiatry Laboratory at McLean Hospital.

Binge eating disorder is a condition in which individuals experience uncontrolled eating binges at least twice a week for a period of at least six months. Binge eating disorder is estimated to afflict between 1 and 5 percent of the American population.

The researchers used a so-called “blind” family interview method, in which one investigator interviewed each of the 300 obese individuals selected for the study (half of whom had binge eating disorder and half of whom did not), while two other investigators interviewed 888 family members of those individuals. The group of 888 included 431 relatives of individuals with binge eating disorder and 457 relatives of individuals without binge eating disorder. The two family interviewers were kept blind to all diagnostic information about the obese individuals whose family members they were evaluating.

The study found a lifetime diagnosis of binge eating disorder in 87 of the 431 relatives of subjects with binge eating disorder and 44 of the 457 relatives of subjects without the disorder. The study also found that relatives of subjects with binge eating disorder were 2.5 times more likely to be severely obese than relatives of subjects without the disorder.

“This observation suggests that whatever genetic factors are causing binge eating disorder are also at play in causing severe obesity,” Hudson said. “The current epidemic of obesity has many causes. This study says that there may be a psychobiological cause for obesity, one that is related to impulsive binge eating.”