Anorexia treatment is very difficult and very often ineffective. Anorexia has the highest mortality rate of any psychiatric disorder and has a worldwide prevalence of 0.5% with the majority of cases being teenage girls. The disorder is characterized by body dysmorphia, persistent fears of weight gain, and the avoidance of treatment.
Over time, those with anorexia develop malnutrition, weak bones and muscles, hormonal disruption, infertility, sexual dysfunction, heart problems, and seizures. Eventually, this will lead to acute illness and death.
A small study published in The Lancet Psychiatry details a very promising new anorexia treatment involving the use of deep brain stimulation to control dysfunctional behaviors. Deep brain stimulation is a technique involving the implantation of electrodes into target areas of the brain. It is currently being used to treat Parkinson’s disease, dystonia (a neurological movement disorder), and tremors with great success. This study is the first time deep brain stimulation has been used as an anorexia treatment.
The small study followed 16 women aged between 21 and 57 years old who had had anorexia for an average of 18 years and were severely underweight (with an average body mass index (BMI) of 13.8). They were selected for the study as all other available treatments did not work for them and they were at risk of early death because of anorexia.
Electrodes were placed into their subcallosal cingulate, an area located in the centre of the brain that has been shown to have altered serotonin binding in patients with anorexia. Once implanted, the electrodes stimulated the area for one year at a level of 5 — 6.5 volts every 90 micro-seconds.
The treatment had few serious adverse events; however, five patients had pain that persisted for longer than usual following the surgery (more than 3-4 days) and one had an infection at the site of the surgery which resulted in the electrodes needing to be removed and re-implanted. Most adverse events were a result of the patients’ chronic anorexia and included having very low sodium and potassium levels. One patient had an unexplained seizure several months after their electrodes were implanted.
During the study, two patients asked to have the electrodes removed, potentially a result of them being uncomfortable with their weight gain. This meant that there were only 14 patients included at follow-up.
For these patients, mental health symptoms improved over the study with mood and anxiety symptoms reducing in five patients and depression reducing in 10 out of 14 patients. They also reported better quality of life.
While psychological symptoms improved soon after the stimulation began, changes in weight started after three months, suggesting that improving mental health symptoms may precede or even enable changes in weight. Over the course of the study, average BMI of the group increased to 17.3 — an increase of 3.5 points — and six patients achieved a normal BMI (of 18.5 or more).
When comparing the scan results for brain activity before treatment and after a year of stimulation, the researchers found that there were changes in the regions linked to anorexia, suggesting that deep brain stimulation was able to directly affect the related brain circuits. This included less activity in the putamen, thalamus, cerebellum amongst other areas, and more activity in the peripheral cortical areas which are also linked to social perception and behaviour.
“Anorexia remains the psychiatric disorder with the highest mortality rate, and there is an urgent need to develop safe, effective, evidence-driven treatments that are informed by a growing understanding of brain circuitry,” said study author, Professor Andres Lozano, University of Toronto, Canada. “While our results show some early promise, more research will be needed before this becomes available for patients with anorexia. Our findings emphasise the need for continued research into novel neuromodulation strategies for anorexia nervosa, and for psychiatric disorders more broadly.”
“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.” said lead author, Dr Nir Lipsman, Sunnybrook Health Sciences Centre, Canada.
The obvious limitations of this study are that the participant pool was very small, there was no control group, and all of the participants knew they were receiving treatment. However, because of the dramatic improvements in both psychological and physical symptoms and the fact that the changes were confirmed with brain scan, the placebo effect is unlikely.
This study and these results are frankly amazing. Until now, roughly half of all women that receive anorexia treatment do not see significant improvement in their symptoms. Using deep brain stimulation, the majority of these women realized significant improvements in depression, mood, and disordered eating behaviors. Obviously, more study is needed but the results are very encouraging.
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