Who doesn't know that smoking pot can make you want to pig out?
Now researchers say it may work the other way around, too.
Children between the ages of 9 and 15 who went on eating binges at least once a week were roughly twice as likely to use marijuana or to show strong signs of depression as those who didn't.
Researchers found that 29 percent of adolescents who had episodes of binge eating later went on to use marijuana, compared with 17 percent of adolescents who never binge ate.
Harvard's Kendrin Sonneville, who studies eating disorders, says her team found a strong connection between these behaviors. But the exact connection — and whether one behavior is causing the other — is unclear.
One theory, she says, is that the same impulsiveness that leads children to binge eat may also be leading them to try marijuana. Another theory is that the strong feelings of shame that often accompany binge eating are one of the causes of depression.
But, Sonneville says, these are only theories. "There's something that may have even preceded the binge eating episode," she says. "We don't know if the binge eating is the start of the chain."
Precisely defining binge eating can also be a little tricky. Sonneville says it's not a run-of-the-mill session of overindulgence. For an episode to officially qualify as binge eating, she says, the overeating has to be accompanied by a loss of control — feelings that you couldn't stop eating if you wanted to.
"It's really the loss of control that's terribly distressing, to feel like you have a behavior you cannot stop," Sonneville says.
Also, these kinds of episodes have to be occurring frequently — on an almost weekly basis — to qualify as a binge eating disorder.
Much more research is needed to determine the true relationship between binge eating, drug use and depression. But Sonneville's findings suggest that binge eating in adolescence could be a flag for other problems to come during the teenage years.
She says doctors and parents should keep an eye out for this kind of behavior, even among children without weight problems.
"Sometimes I worry that we're focused so much on the eating habits of obese kids that we overlook other kids," she says. "That's the bigger nuance. Eating habits are not just something we're concerned with in the obese population."