UvA PhD candidate applies deep brain stimulation to anorexia patients for the first time
Can brain connections in patients with severe anorexia be reconfigured? Psychiatrist and UvA doctoral student Marloes Oudijn conducted experimental research into deep brain stimulation for this eating disorder. “In the Netherlands, we are the first and only ones to have done this.”
“Very intense,” is how Marloes Oudijn, a psychiatrist at Amsterdam UMC, describes the research she conducted in recent years on four patients with a severe form of the eating disorder anorexia nervosa (AN). “Precisely because the patient group is so vulnerable, and no one knew exactly what the outcome of the study would be.”
Anorexia, especially the chronic form, has the highest mortality rate of all psychiatric diseases at 5.9 percent. Deep brain stimulation (DBS) could be a lifesaver for severely ill patients who do not respond to existing treatments, Oudijn believes.
Participating in the study was not an easy decision, as DBS requires a surgical procedure in which a neurosurgeon inserts two electrodes into the brain to restore healthy connections. Patients were also studied intensively for two to three years with brain scans and questionnaires.
DBS is already a proven treatment method for Parkinson’s disease and in psychiatric illnesses such as obsessive-compulsive disorder but is still in the experimental phase for anorexia. Worldwide, only a few centers are researching deep brain stimulation in anorexia. “In the Netherlands, we are the first and only ones to have done this.”
How does anorexia work in the brain?
“A certain part of the brain, the reward system, normally makes us feel like eating, because a nice piece of cake produces a rewarding feeling, just like with drugs. In patients with anorexia, that reward system seems to have taken on a reverse effect. Eating does not work as a reward, but instead, not eating, excessive exercise, vomiting, and getting as low a number on the scale as possible are rewarding. That’s why I find it such a fascinating disease, because your body is evolutionarily designed to survive, and you need energy to do that. Patients with anorexia can literally starve themselves to death.”
Isn’t four subjects too few for a study?
‘The group is indeed too small to run statistics on it. But if you know what is involved, it is already very remarkable that four patients worked on this so intensively for three years. The disadvantage is that the patients knew very well that they were the only patients in the Netherlands, which put them in a unique position. Ideally, we would have also had a control group or could have had the possibility to turn off the DBS for a while to make the measurements more objective. The patients’ hope for a cure also played a role, which might have colored the results.
Does deep brain stimulation work for anorexia?
“In terms of weight, on average we saw an increase from a BMI of 12 (very severely underweight) to a BMI of 17, which is slightly underweight. This increase was most pronounced in two of the four subjects. The core symptoms of anorexia also decreased, such as the feeling of being too fat, exercising, and wanting to lose weight, and the patients’ mood also improved.”
“What I found most interesting is that the eating disorder behaviors of vomiting, exercising, and losing weight that were so rewarding before became less and less so. The patients all said that they still did it, but it didn’t feel as good.”
“Something else took its place. For example, in some of the patients we saw that, especially in the beginning, there was an increase in other self-harming behaviors, such as cutting or suicide attempts. Because that was so striking, severe, and risky, we devoted an entire chapter to explaining the link between anorexia nervosa and self-harming behavior.”
What was the result?
“The assumption is that there is an underlying, disturbed regulation of emotions whereby patients suffer from intense emotions that are often out of proportion to the situations that provoke them. This may stem from negative or traumatic events, attachment disorders, or a negative self-image. Very simply put, the eating disorder is a way to blunt those feelings, and when that no longer works, patients look for another way.”
“That may sound like a negative outcome, but at the same time that behavioral change exposed the underlying emotions more. Psychotherapy on underlying emotion regulation issues that had previously failed to work then actually worked in two of the four patients after DBS. So it seems that DBS provides a kind of entrance to that deeper layer via the reward system.”
What can you do with these results?
“DBS treatment for anorexia is still in a very experimental phase. This study has given us more insight into how it works, how to conduct such a study properly, and what results are meaningful. I will appeal in my defense on Monday for more follow-up research, also in a less seriously ill group, so that the results can also be extrapolated. In this way, DBS may eventually become a registered treatment that offers a more hopeful perspective to this group of anorexia patients.
Marloes Oudijn will receive her doctorate on Monday, February 5th at 2:00 p.m. for her dissertation, “Life on a scale: Deep brain stimulation in anorexia nervosa.” The defense will take place in the Agnietenkapel and is free to attend.
