Anxiety And Eating: The Relationship Between Anxiety Disorders And Eating Disorders
Those suffering from eating disorders often have psychiatric symptoms as well, such as depression, anxiety disorders, and obsessive-compulsive behavior. Anxiety disorders very often pre-date, and are comorbid with, the eating disorder and, if not treated, can remain after recovery. Anorexia Nervosa (AN) is generally characterized by the refusal to eat enough calories to sustain oneself, while Bulimia Nervosa (BN) is characterized by bingeing on food and then purging oneself.
The relationship between anxiety and disturbed eating has been the subject of several studies. It is hypothesized that social fears, discomfort with the thought of being judged in social settings, or generalized anxiety may be an important first step to developing an eating disorder, particularly AN. With both AN and BN there may be genetic determinants that play a role in the connection with anxiety. Lisa Lilenfeld, Ph.D., of Georgia State University, is taking part in a large international collaborative study, funded by the Price Foundation, which is investigating genetic factors that may contribute to the development of eating disorders. According to Dr. Lilenfeld, "Eating disorder are substantially mediated by genetic factors," and this study is working to determine what those genes might be. The evidence indicates that certain anxiety disorders are more prevalent with eating disorders in general, and specific anxiety disorders can be linked to specific eating disorders. Suffers of AN were found to have higher rates of Obsessive Compulsive Disorder (OCD), Obsessive Compulsive Personality Disorder (OCPD), as well as Generalized Anxiety Disorder (GAD), social phobia and simple phobia. Women diagnosed with BN have higher rates of Post Traumatic Stress Disorder (PTSD) and ODC.
Anorexia Nervosa and Anxiety Disorders
There are two subtypes of Anorexia Nervosa. The first is a the restricting type, which is characterized by dieting, fasting or excessive exercise. The second is the binge-eating/purging type in which the individual will eat, usually small amounts of food, and then purge through the use of laxative, diuretics, enemas or self-induced vomiting. Women with restrictive AN tend to have high rates of OCPD. The need to control food intake coincides with the inflexibility and perfectionism displayed with that particular personality disorder.
OCD seems to be specific to sufferers of both types of AN, and there may be a biological reason for this. According to Dr. Lilenfeld, both disorders are associated with elevated levels of serotonin, one of the neurotransmitters associated with anxiety and depression. Another reason for the connection may be that, as with OCPD, the obsessive nature of the eating disorder coincides with the nature of the anxiety disorder. The anxiety usually comes first, with age-of-onset in childhood, while the onset of the eating disorder is usually in adolescence.
Social Anxiety Disorder and Panic Disorder are also prevalent in women with AN, although Panic Disorder usually manifests itself after the onset of the eating disorder. As mentioned above, anxiety about social situations is not surprising in anorexic women who, studies have shown, then to exhibit shyness, avoid dating, attending parties, and public speaking.
Bulimia Nervosa and Post Traumatic Stress Syndrome
In the National Women's Study over 3,000 women were questioned about their history of aggravated and sexual assault, PTSD, and both Bulimia Nervosa and Binge Eating Disorder (BED). It was found that there were much higher rates of aggravated and sexual assault in women who had developed BN. In the majority of bulimic women the assault and subsequent development of PTSD predated the eating disorder, this suggests that victimization contributed to the development of the eating disorder. The odds of developing BN are greater for women with PTSD, even if the trauma resulting in the PTSD was not assault. Even when PTSD has been diagnosed and treated these women are at a higher risk of developing BN than women who have not been assaulted and subsequently developed PTSD.
It is unclear whether the eating disorder is a response to the heightened level of anxiety associated with sufferers of PTSD. According to Timothy Brewerton, M.D., of the Medical University of South Carolina and one of the principle researchers in the National Women's Study, "Purging as opposed to bingeing, seems to be the key behavior linked to PTSD." One explanation for this, according to Dr. Brewerton, is that the act of purging has a numbing effect, and many bulimics report that they feel more relaxed and less anxious after purging. It is interesting to note, however, that women with BED are less likely to also have PTSD than women with BN and that there is no higher rate of victimization among these women. Women with BED also recover from PTSD more quickly than bulimics, according to Dr. Brewerton, the purging and subsequent malnutrition that is characteristic of bulimia affects the ability to recover.
Although much research has been focused n bulimic women who have experienced childhood sexual trauma, whether or not they have PTSD, it is clear that women who have PTSD from any type of trauma (for example, aggravated assault, emotional abuse or bereavement) have a higher risk for BN. PTSD is the risk factor for developing BN, not childhood sexual trauma.
Websites to visit for more information on eating disorders:
- National Association of Anorexia Nervosa and Associated Disorders at www.anad.org
- Eating Disorders Awareness and Prevention, Inc. at www.edap.org
This article, written by Geralyn Lederman, Ph.D., is reprinted from the Anxiety Disorders Association of America's bimonthly newsletter, the Reporter. If you would like to subscribe, please visit their website at www.adaa.org, click on "ADAA Membership" and go to "Consumer Membership," or call the ADAA at 301-231-9350.