Implanting electrodes deep in the brain may help treat chronic anorexia. Anorexia has the highest mortality rate of any psychiatric disorder; patients experience persistent, overwhelming concerns about their bodyweight and appearance, often coupled with mood and anxiety disorders, leading to dangerously low bodyweight. Malnourishment can cause weak bones and muscles, heart problems, and seizures, yet many patients avoid medical assistance, denying they have a problem. Even when patients do seek help—typically a combination of behavioral therapy, nutritional support, and simply stabilizing their physical condition—the disorder can be stubbornly resistant to treatment.
Now, a study published in The Lancet Psychiatry suggests that deep brain stimulation—implanting electrodes that target certain areas of the brain—may improve mood, anxiety, and wellbeing among those with chronic anorexia. Those immediate effects were followed by healthy weight gain, suggesting that improving mental health preceded or even enabled changes in weight. The study was small, but indicates the procedure is safe and could improve some anorexia symptoms. Still, more research is needed.
Researchers selected 16 women, between 21 and 57 years old, all of whom had had anorexia for an average of 18 years. They were severely underweight, and selected for the study because other treatments didn't work for them. All were at risk of early death because of the disorder. Electrodes were implanted in their heads, targeting an area at the center of the brain shown to have altered serotonin binding in anorexia patients. (The same technique, aimed at different areas, has proven effective in treating Parkinson's disease, dystonia, and tremors.) The electrodes stimulated that area at short, regular intervals for one year.
The study looked to prove the safety of the procedure and its effect on BMI, mood, anxiety, and wellbeing. But it also examined the treatment how brain activity changed brain activity. Using PET scans, researchers found changes in the areas linked to anorexia—specifically, they found less activity in the less activity in the putamen, thalamus, cerebellum, and other areas. There was also more activity in peripheral cortical areas linked to social perception and behavior. That suggests the deep brain stimulation did have an effect.
There are some limitations to the research, including its small sample size and lack of a control group. Women in the study knew they were being treated, which means the possibility of a placebo effect; the researchers note, though, that the PET scans support their results. "Our study suggests that a focal brain intervention, deep brain stimulation, may have an impact on the circuitry of symptoms that serve to maintain anorexia and make it so difficult to treat," the study's lead author, Nir Lipsman, told The Lancet Psychiatry. In other words, it's a small, early, but promising first step in treating a difficult and often life-threatening disorder.