Non-invasive brain stimulation might be able to alleviate symptoms of anorexia nervosa, a study out of King's College London is reporting.

For this study, the researchers wanted to see if repetitive transcranial stimulation (rTMS) could be effective at treating anorexia, an eating disorder that is characterized by an obsession with losing weight and an unhealthy relationship with food. The treatment has already been approved for depression.

The researchers recruited 49 anorexic patients who took part in food exposure and decision-making activities before and after one session of rTMS. Their symptoms were also monitored for any changes. A control group of participants received fake rTMS.

The food exposure task was designed to trigger symptoms of anorexia. During the task, the patients had to watch a two-minute long clip of people eating foods that were appetizing, such as chocolate and chips. Every item that the patients saw was also placed right in front of them. After the clip ended, the patients had to rate the foods based on their smell, taste and appearance. Patients also had to report how much they wanted to eat the foods.

For the decision-making part of the study, the researchers asked the participants to choose between a smaller amount of money that they could get immediately and a larger, fixed amount that would only be available to them after one week, one month, one year or two years.

The researchers stimulated the self-regulation region of the brain, known as the dorsolateral prefrontal cortex. Anorexic people often have regulatory problems. They found that rTMS was able to change brain activity in this region.

"We found that one session of rTMS reduced the urge to restrict food intake, levels of feeling full and levels of feeling fat, as well as encouraging more prudent decision-making," said Jessica McClelland, a post-doctoral researcher at the Institute of Psychiatry, Psychology & Neuroscience at King's College London. "Taken together, these findings suggest that brain stimulation may reduce symptoms of anorexia by improving cognitive control over compulsive features of the disorder."

Senior author of the study, Professor Ulrike Schmidt, added: "Anorexia nervosa is thought to affect up to 4 percent of women in their lifetime. With increasing illness duration, anorexia becomes entrenched in the brain and increasingly difficult to treat. Our preliminary findings support the potential of novel brain-directed treatments for anorexia, which are desperately needed."

The researchers, who published their study in PLOS ONE, will be testing rTMS as a treatment for anorexic patients in a clinical trial.