Purging disorder is an eating disorder in which people afflicted will purge themselves after eating a meal, such as by vomiting or using laxatives. Purging disorder is not currently defined as a separate mental health disorder by the DSM IV. Instead, it is listed as an Eating Disorder Not Otherwise Specified (EDNOS). However, there is significant evidence and support for making Purging disorder a new mental health disorder in future editions of the DSM.
How Purging Disorder Differs from Anorexia Nervosa and Bulimia Nervosa:
Purging disorder shares many similar characteristics with both anorexia and bulimia. With all of these eating disorders, people afflicted are preoccupied with body weight and self image. They make significant efforts to control their weight in attempt to meet unrealistic goals. People with these eating disorders are also afflicted by feelings of guilt for eating.
One of the main factors that differentiate purging disorder from anorexia nervosa is that people with purging disorder are of a normal weight. To meet the diagnostic criteria for anorexia, patients must be significantly underweight and also have specific health problems associated with being underweight. In contrast to bulimia nervosa, people with purging disorder do not binge eating before their purging episodes. People with purging disorder will typically eat what can be considered normal amounts of food but will still purge after eating even small amounts of food.
Another core difference in people with purging disorder compared to bulimics and anorexics is that they will often have distorted perceptions and reactions to meal portions. The people with purging disorder may feel full and can feel like they have excessively eaten even after a small meal or snack. People with purging disorder have also reported feeling out of control of their eating habits even though they are eating amounts which are considered normal.
The most common method of purging is vomiting. However, there are other ways that a person with this eating disorder may purge after meals, including improper use of:
Note that any of these ways of purging can take place or be performed for various reasons. Purging disorder does not include proper or natural methods of purging, such as enemas for health reasons or vomiting as a reaction to illness.
There are currently no diagnostic criteria for Purging disorder as it is defined as an Eating Disorder Not Otherwise Specified. However, the DSM is taking under consideration inclusion of Purging Disorder for the DSM fifth edition. According to analysis, the diagnosis criteria of Purging disorder would likely include
- Purging used to influence body weight/shape without other methods of controlling weight/shape (such as food restriction).
- A minimum frequency and duration of purging episodes yet to be established.
The studies on purging disorder have not used any uniform requirement for frequency and duration of episodes. The frequency of purging episodes in the studies typically ranged from once to twice weekly. The duration of episodes ranged from one to four months.
Purging disorder is a common eating disorder with some studies putting its prevalence at nearly 7% of all eating disorder referrals and about 17% of EDNOS. In the general population, purging disorder is not common but is hardly rare. Studies put the lifetime prevalence of the disorder at 1.1%-5.3%. A study of women in college in the US put the prevalence of purging disorder at about 0.7%.
As with anorexia and bulimia, purging disorder is much more common in women than men. The peak age of purging disorder is higher than anorexia or bulimia, with average onset for purging disorder at about 20 years old compared to adolescence for anorexia and bulimia.
One may infer that people with purging disorder would likely later meet the diagnostic criteria of anorexia as purging may lead to significant weight loss, the diagnostic criterion which differentiates anorexia from purging disorder. However, studies have shown that this is not the case with only rare cases of purging disorder later developing into anorexia. Rarely has purging disorder developed into bulimia.
There is currently insufficient evidence about the causes of purging disorder though it may be inferred that the causes are of a similar nature to the eating disorders anorexia and bulimia. These causes may include biological factors including genetics and neurotransmitter imbalances as well as psychosocial factors such as instable home lives or sexual abuse.
Currently, there is not clinically significant evidence dictating the treatment of purging disorder. Thus, many physicians may use the established treatments for bulimia or anorexia for purging disorder. These treatments may consist of cognitive behavioral therapy, medications, and nutritional counseling. Purging disorder is not typically treated with hospitalization as patients are of a normal weight.
American Psychiatric Association. (2000). Diagnostic and Statistical Manual of Mental Disorders (Revised 4th ed.). Washington, DC: Author.
Keel, Pamela K., PhD, and Ruth H. Striegel-Moore, PhD. “The Validity and Clinical Utility of Purging Disorder.” International Journal of Eating Disorders. 42 (2009): 706-719.
Miller, Karl E., MD. “Practice guideline for the treatment of patients with eating disorders.” American Journal of Psychiatry. 157.suppl (Jan 2000): 1-39. Retrieved from www.aafp.org.
“New Eating Disorder Identified.” ScienceDaily.com. Science Daily. 4 Sept 2007. Web. <www.sciencedaily.com/releases/2007/09/070904151346.htm#>.