Bulimia Nervosa: Not Just a Psychological Disorder

According to the American Psychiatric Association, Bulimia Nervosa is characterized by “repeating episodes of of binge eating and compensatory behaviors, such as excessive
exercise, self-induced vomiting, diuretic or laxative abuse.” It, along with other eating disorders such as Anorexia Nervosa, is most notably a psychological disorder, and thus is typically treated through therapy.
What is to blame?
Most easily, we are able to cast blame on society and media. The use of photo-shop and alterations of the such lead to unattainable expectations for today’s youth (pre-teens, adolescents, early 20’s), while also having reports of eating disorders in older populations. Women AND men (affects both sexes) with the disease may never see themselves as having the “perfect” body, which adds to the psychological downfall leading into these dominating disorders. However, there is a certain pathophysiology revolving around Bulimia Nervosa, into which we studied.
The binge–purge cycle is introduced by first, overeating; which is perceived as ‘out of control.’ Purging acts to relieve or mitigate the distress of this state of being ‘out of control’ and provides an euphoric sense of increased control over food intake or weight. If this uncontrollable food consumption is so, well… uncontrollable.. why do it in the first place? As many people know eating releases endorphins and a lot of ‘feel good’ hormones, encouraging the person to seek out those foods he or she may like. In Bulimia, the act of overeating and compensatory behavior temporarily reduces the anxiety of feeling out of control. Thus this ‘out of control’ — ‘back in control’ cycle is reinforced through eating, and the process continues. The process of initiating binging and purging may be more than just through the media wanting us to look good, but may be because of our own susceptibility to external stressors and compulsive habits.
Compulsive traits of an individual have been found to be linked to serotonin dysfunction, notably through genetic polymorphisms within the serotonin system. With that being said, obsessive compulsive disorders share a common dysregulation in serotonin function, sharing some similar behaviors with bulimia. Thus, the serotonin system appears to be a unifying neurobiological system in which we need to understand more about its role in eating disorders such as bulimia.
One possible pathophysiology is of interest, and that is the vago-vagal reflex. This reflex is serotonergic in nature, and if serotonin dysfunction is present, this reflex may not function properly. This reflex is responsible for the ability to store food in your stomach. When food is consumed, the stomach muscles relax in order to provide more room, and reduce the pressure inside the lumen. When this reflex is dysfunctional, the food can still reach the stomach, but the walls are not relaxed, resulting in an increase of pressure. After many episodes of binging and purging, serotonin levels may become more and more irregular, thus reinforcing an improper reflex, resulting in pressure build-up, and then decreased ability to keep food down, resulting in a positive-feedback loop.
The dysfunction of the vago-vagal reflex is one of many physiological manifestations of bulimia. It’s a cycle of reinforcing the purging, thus leading back to seeking the necessity to over-eat. Although there are noted psychological anomalies associated with bulimia, we must first recognize that this disorder has to also be physiologically treated, and thus, the disease becomes even harder to cure than initially thought.