According to researchers at the University of Colorado, even after anorexia nervosa patients undergo treatment and gain considerable weight, their brains remain altered. This means they are not cured, and are at risk for relapse.
The study, lead by Dr. Guido Frank, followed 21 adolescent anorexia nervosa patients before and after treatment, and compared them to a control sample of adolescents with no eating disorder. The researchers found that even after treatment, the adolescents in the former group had a changed and elevated brain reward circuit system compared to their controls.
“That means they are not cured,” said Frank. “This disease fundamentally changes the brain response to stimuli in our environment. The brain has to normalize and that takes time.”
The central reward system governs the body’s desire to eat, which affects appetite and food intake. Patients with anorexia nervosa have an altered reward system. More specifically, they have altered dopamine expression, a neurotransmitter responsible for sending messages to the brain regarding reward-related behaviours.
Changes in dopamine expression play a large role in the pathology of eating disorders. Results showed that in the adolescent sample of 15 to 16 year old girls, dopamine levels were heightened, although somewhat more normalized but still elevated post treatment.
The more altered the brain, the harder it is to actually cure anorexia nervosa patients of the disease. In other words, the more altered the brain, the harder it is to have patients gain weight and keep it on.
“Anorexia nervosa is hard to treat. It is the third most common chronic illness among teenage girls with a mortality rate 12 times higher than the death rate for all causes of death for females 15-24 years old,” Frank said. “But with studies like this we are learning more and more about what is actually happening in the brain. And if we understand the system, we can develop better strategies to treat the disease.”
Frank concludes that more research needs to be done to determine why this is happening, but that understanding these mechanisms can help predict treatment success.