Anorexia Nervosa: Does the Eating Disorder Hijack Our Brains?

Colin Uyeki

Every 62 minutes someone in the U.S. dies as a result of an eating disorder.4 The most notorious is Anorexia Nervosa, which affects over 1% of the general population, and is the deadliest of all psychiatric disorders.2,3,5

Anorexia is characterized by dramatic weight loss, which is often attributed to self-induced starvation and excessive, compulsive exercise.2,4 Until recently, anorexia was thought to be the result of social, genetic, and psychological factors.4,7,8 Researchers have now concluded that specific areas of the brain associated with reward contribute to the onset and persistence of this disease.4,6 The thought amongst researchers is that anorexic behavior may change the brain’s activity by suppressing areas that help us perceive food as rewarding and good.8 When anorexic behavior persists these changes begin to become more solidified until the disease has hijacked our ability to find food rewarding.

If this disease is hijacking our brains, how do we regain control?

Current treatment for anorexia includes medical intervention to restore physical health, but the focus is on the stomach of the patient, not the brain.2 Even different types of therapy, the most widely used treatment for anorexia, isn’t always enough. Currently, over 20% of individuals who receive help relapse, and over 10% die. 5

Fortunately, alternative forms of treatment that focus on the brain may be just over the horizon.

Most recently, a research group in Australia used a rodent model of anorexia—Activity-Based Anorexia (ABA)—to see if weight loss associated with the condition could be prevented and mitigated by activating a reward pathway in the brain that anorexia is thought to suppress.4

The ABA protocol mimics the self-induced starvation and compulsive exercise of anorexia by pairing time-restricted food access with unlimited access to a running wheel.4 To assess the effects of activating this pathway, it was activated in the rats either at the start of the trial or after 20% of their starting body weight was lost (this is proportionate to a 150lbs human losing 30lbs in just a few days).4

Remarkably, the study found that activating the reward pathway helped prevent weight loss and improved survival in rats with ABA.4 In both cases, the rats that had activated pathways ate more than the regular(control) rats, and also survived longer. All of this change was in spite of the fact that there was no difference in the amount that each group used the running wheel throughout the experiment.

This study is a practical assessment of the potential for brain activation in treating anorexia. The food didn’t get progressively more rewarding during the experiment, and the rats’ activity levels didn’t change either. The study shows that the activation of the reward pathway in the rats, an internal change, resulted in increased food intake. If anorexia hijacks the brain and changes how we perceive food, force-feeding and therapy will do little to change that. Maybe we should try to tackle this problem from the inside out, fixing the brain before we fix the behavior.

References/Bibliography

  1. “Anorexia Nervosa.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 23 Aug. 2017, www.mayoclinic.org/diseases-conditions/anorexia/diagnosis-treatment/drc-20353597.
  2. “Anorexia Statistics & Facts.” American Addiction Centers, americanaddictioncenters.org/anorexia-treatment/facts-statistics/.
  3. Auquier, P., Lançon, C., Rouillon, F., & Lader, M. (2007). Mortality in schizophrenia. Pharmacoepidemiology and Drug Safety16(12), 1308–1312. https://doi.org/1002/pds.1496
  4. Foldi, C. J., Milton, L. K., & Oldfield, B. J. (2017). The Role of Mesolimbic Reward Neurocircuitry in Prevention and Rescue of the Activity-Based Anorexia (ABA) Phenotype in Rats. Neuropsychopharmacology42(12), 2292–2300. https://doi.org/1038/npp.2017.63
  5. Fields, R. Douglas. “The Deadliest Disorder.” Psychology Today, Sussex Publishers, 11 Mar. 2011, www.psychologytoday.com/blog/the-new-brain/201103/the-deadliest-disorder-0.
  6. Frank, G. K. W., Shott, M. E., Riederer, J., & Pryor, T. L. (2016). Altered structural and effective connectivity in anorexia and bulimia nervosa in circuits that regulate energy and reward homeostasis. Translational Psychiatry6(11), e932. https://doi.org/1038/tp.2016.199
  7. Gorwood, P., Blanchet-Collet, C., Chartrel, N., Duclos, J., Dechelotte, P., Hanachi, M., … Epelbaum, J. (2016). New Insights in Anorexia Nervosa. Frontiers in Neuroscience10. https://doi.org/3389/fnins.2016.00256
  8. Kaye, W. H., Bulik, C. M., Thornton, L., Barbarich, N., Masters, K., & the Price Foundation Collaborative Group. (2004). Comorbidity of Anxiety Disorders With Anorexia and Bulimia Nervosa. American Journal of Psychiatry161(12), 2215–2221. https://doi.org/1176/appi.ajp.161.12.2215
  9. Sareen, J., Cox, B. J., Afifi, T. O., de Graaf, R., Asmundson, G. J. G., ten Have, M., & Stein, M. B. (2005). Anxiety disorders and risk for suicidal ideation and suicide attempts: a population-based longitudinal study of adults. Archives of General Psychiatry62(11), 1249–1257. https://doi.org/1001/archpsyc.62.11.1249
  10. “Eating Disorder Statistics • National Association of Anorexia Nervosa and Associated Disorders.” National Association of Anorexia Nervosa and Associated Disorders, www.anad.org/get-information/about-eating-disorders/eating-disorders-statistics/.
  11. Picture URL https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwiUu9WQyv7WAhXkjVQKHW6lBtAQjhwIBQ&url=https%3A%2F%2Fwww.sciencenews.org%2Farticle%2Fanorexic-brain&psig=AOvVaw3LqfG3AkXsXGdiGao_1JKQ&ust=1508567470405265

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