Many anorectic women also indulge in occasional eating binges, and half of them make the transition to bulimia. About 40% of the most severely bulimic patients have a history of anorexia.
Bulimia nervosa is defined as two or more episodes of binge eating (rapid consumption of a large amount of food, up to 5,000 calories) every week for at least three months. The binges are sometimes followed by vomiting or purging (use of laxatives or diuretics) and may alternate with compulsive exercise and fasting. The symptoms can develop at any age from early adolescence to 40, but usually become clinically serious in late adolescence.
Bulimia is not as dangerous to health as anorexia, but it has many unpleasant physical effects, including fatigue, weakness, constipation, fluid retention (bloating), swollen salivary glands, erosion of dental enamel, sore throat from vomiting, and scars on the hand from inducing vomiting. Overuse of laxatives can cause stomach upset and other digestive troubles. Other dangers are dehydration, loss of potassium, and tearing of the esophagus. Women with diabetes, who have a high rate of bulimia, often lose weight after an eating binge by reducing their dose of insulin. According to recent research, this practice damages eye tissue and raises the risk of diabetic retinopathy, which can lead to blindness.
In summary these two disorders have much in common like the drive to be thin, an unhealthy fascination with food and the need to be perfect. But the important distinctions are that anorexics do not have a healthy body weight but bulimics may be underweight but they can also be overweight. Anorexics deny that they are hungry or that they have a disorder whereas bulimics are most definitely aware of their hunger and of their disorder. Also anorexics tend to have less antisocial behavior because they strive to please everyone, but the bulimics will tend to be more antisocial. In anorexics their menstrual cycle completely stops but in bulimics its normally just very irregular.
The differences and the similarities in the symptoms of the two eating disorders are plain to see, but what are far more difficult to distinguish between are the explanations and the causes of these two disorders.
Unfortunately because of the way that these two disorders overlap each other most research that has gone into this area, places them both under one umbrella called eating disorders. Most explanations are applied to both making none or very little distinction between them. This to be fair is not for no good reason and without reasonable basis. T Van Der Ham et al studied variations and differences in the path of illness in a 4-yr follow-up study of 25 anorexic and 24 bulimic teenagers. Participants were evaluated on the Morgan and Russell Outcome Schedule (H. G. Morgan and A. E. Haywood, 1988). 47% of the participants had good, 43% midway, and 10% bad outcome scores after 4 yrs. The groups differed as to the severity and type of eating disorder, but were similar in mental, psychosocial, and psychological symptoms during the sickness. Eight percent of the anorexic participants became bulimic. The author concluded that the 2 illnesses could be considered different symptom patterns of 1 basic eating disorder in which the obsession with food and a distorted body image are the core symptoms.
The psychodynamic explanations focus on the sufferers’ of anorexia and bulimia, relationship with their parents and how the sufferer has a requirement to develop their own identity and become separate from them. This approach believes that there are three main possible causes. Firstly their unconscious desire to stay pre-pubescent and that way escape the responsibilities of adulthood. Secondly they unconsciously don’t want to face up to their sexuality and particularly pregnancy. And thirdly Bemis (1978) found it was their unconscious need to control their lives and assert independence from their parents. But this theory is doubtful for both disorders because if it was all about independence and avoidance of sexual maturity then why is it mainly only females that suffer both.
For both disorders the same behavior related explanations are given. In western cultures we tend to put on a pedestal images of thin women and link thinness with good health. Uncontrolled eating and weight gain cause anxiety, which anorexics and bulimics can avoid by controlling their weight.
But it is difficult to use this explanation when explaining why blind people get anorexia or bulimia that cannot have images of beauty.
There is no evidence, as yet that genes cause anorexia nervosa or bulimia. Instead researchers look at eating disorders in families. Holland et al (1984) found a 55% concordance rate for Monozygotic twins compared with only 7% for Dizygotic twins. Wade et al (2000) found similar levels in their study of 2163 female twins suffering from anorexia and bulimia. Bulik et al (2000) review of twin studies research found that it was not possible to draw firm conclusions about the precise contribution of genetic and environmental contributions to anorexia. However they found that there was evidence that bulimia if familial with genetic factors more prominent than the effects of shared environment.
There are also biochemical explanations for both. It is believed that the Lateral hypothalamus (LH) which produces hunger and the Ventromedial hypothalamus (VMH) which depresses hunger, work together to set up a ‘weight thermostat’ which maintains a set point for healthy weight. If the thermostat rises above this point, the VMH is activated, if weight falls below the weight set point, the LH is activated. It is possible that a malfunction in the hypothalamus might explain both of the eating disorders.
All of the above explanations have highlighted how similar the two disorders are but there is one explanation, which shows that the causes of bulimia may be slightly different to anorexia. This is the role of Serotonin. Walsh et al has shown that the neurotransmitter serotonin might be the cause of bulimia. Low levels of serotonin were found to be associated with binge eating.
Information and previous studies show that in so many ways anorexia and bulimia are very similar but there are a few differences between the symptoms and the causes.
REFERENCES
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; ; (1994). A four-year prospective follow-up study of 49 eating-disordered adolescents: Differences in course of illness. . Vol 90(3): 229-235.
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; (1985). Racial and socioeconomic influences in anorexia nervosa and bulimia. , Vol 4(4): 479-487.
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; ; , (2000). A study of temperament and personality in anorexia and bulimia nervosa. , Vol 14(4): 352-359.
