Along with therapy, medical care, and work with a dietitian, medications can be used to help treat some eating disorders. However, to date, there's only one — an antidepressant— approved specifically to treat bulimia. A controversial stimulant (Vyvanse) is the only drug approved to treat binge-eating disorder. And there aren't any medications that are FDA-approved to treat anorexia.
With seemingly endless choices for drugs designed to treat anxiety and depression, why are the options for those dealing with eating disorders so limited? Part of the problem is that we know far less about the way eating disorders work in the brain compared to other disorders, says Rachel Marsh, PhD, associate professor of medical research in psychiatry at Columbia University Medical Center.
For instance, when it comes to depression, we may not know the exact neural mechanisms involved, but we do know that they involve specific neurotransmitters (e.g.dopamine and serotonin) and the degree to which your brain is able to adapt. And we know that, for many, antidepressants targeting those systems are an effective way to manage their symptoms. Because eating disorders often occur alongside other disorders, such as anxiety or depression, drugs designed to treat those issues may help ease symptoms of both conditions. But there's still a distinct lack of medications on the market specifically for the treatment of eating disorders.
Part of the issue is that these disorders are particularly challenging to study. For instance, Dr. Marsh says that it can be difficult to tell whether the differences in brain activity that you see in ED patients versus a healthy control group are truly due to the disorder or are actually due to malnourishment.
And that's if you can find enough participants for the study in the first place. "When you have somebody with a disorder like OCD or depression they want to get better," Dr. Marsh says. "But [eating disorders] are hidden disorders, and [potential] participants don't necessarily want treatment because...they assume that if they get treatment they'll gain weight."
Plus, despite the fact that the effects of eating disorders can be devastating (and even lethal), research into the mechanisms behind them is still under-funded, according to the National Eating Disorders Association.
Our understanding of these illnesses is developing, though: "In both bulimia and anorexia, there seems to be an imbalance between reward processes and cognitive control processes," Dr. Marsh says. People with anorexia tend to be almost "hyper-controlled," she says, similar to people with obsessive-compulsive disorder. On the other hand, people with bulimia tend to be "under-controlled," meaning they act more impulsively. And, as Dr. Marsh's research has shown using brain scanning techniques, the brain areas involved in control and impulsivity operate differently in those dealing with eating disorders. So in the future, it might make sense to develop a drug that would affect these processes.
Another related line of research has looked at eating disorders as if they were a substance use disorders (with food being the "substance"). But depending on the study, you'll find wildly contradictory conclusions about the way the reward circuit is working here. "We’ve implicated the reward circuit, and we know that's modulated by dopamine," Dr. Marsh explains. "But there just hasn’t been enough research done to really understand how the reward circuit is dysfunctional in these disorders [in order to create drugs to target that system]."
So for now, we wait for further research and approval — and rely on the treatment options we already have.