bulimia nervosa

n. Bulimia nervosa, first described as a variant of anorexia nervosa, was identified in 1979 but probably commenced between the 1940s and 1960s. Bulimia, simply meaning “overeating,” has been recognized since antiquity. This is, however, not relevant to the origins of bulimia nervosa. In 1979, Gerald Russell revealed three sets of disturbances in his patients: (1) intractable urges to overeat, (2) avoidance of fattening effects of food by vomiting and/or abusing purgatives, and (3) a morbid fear of becoming fat. Russell also concluded that there had often been a previous episode of anorexia nervosa.

When DSM-III was published, it included the term bulimia, but it differed from bulimia nervosa. Specific psychological disturbances, such as the patient’s fear of fatness, were not given enough emphasis. Also, the diagnosis excluded patients in whom the bulimic episodes were attributable to anorexia nervosa. Bulimia nervosa, as it is considered today, was mostly unknown until the 1970s. After the 1970s, the disorder became relatively common.

Bulimia nervosa exhibits recurrent episodes of binge eating. An episode of binge eating is characterized by the following:

• eating in a discrete period of time (e.g., within any 2-hour period) an amount of food that is definitely larger than most people would eat during a similar period under similar circumstances
• a sense of lack of control over eating during the episode (e.g., a feeling that one cannot stop eating or control what or how much one is eating)

The most prominent behavioral characteristic of bulimia nervosa is the frequent incidence of binge-eating episodes. Individuals with bulimia nervosa consume a variety of foods during a binge. The most typical is the consumption of desserts and snack foods. Individuals also consume large amounts of liquids to assist in vomiting. Bulimia nervosa involves recurrent inappropriate compensatory behavior in order to prevent weight gain, such as self-induced vomiting; misuse of laxatives, diuretics, enemas, or other medications; fasting; or excessive exercise. Individuals engage in purging behaviors to avoid weight gain. An individual is overconcerned with body shape and weight and bases his or her self-esteem on these aspects of appearance. The person feels under pressure to diet and to lose weight, and when he or she does not lose weight or gains weight, he/she reports feeling distressed. Many individuals with bulimia nervosa eventually induce vomiting not only after large binges but also after the consumption of any meal, whether large or small. The key features of bulimia nervosa are binge eating (large amounts of food and perceived loss of control), purging behavior, intensive exercise, hoarding and/or stealing food, going to the restroom/shower after meals, and shame and fear of gaining weight.

To be diagnosed with bulimia nervosa, both the bingeing and purging behaviors need to occur on average at least twice a week for 3 months. Bulimia nervosa usually emerges after a period of dieting. The disturbance does not occur exclusively during episodes of anorexia nervosa. That is, if an individual meets the criteria for both anorexia nervosa and bulimia nervosa, he/she is given the diagnosis of anorexia nervosa, binge-eating/ purging type.

Bulimia nervosa has two subtypes: purging typeand nonpurging type. The characteristic of the purging type is that during the current episode of bulimia nervosa, the person has regularly engaged in self-induced vomiting or the misuse of laxatives, diuretics, or enemas. The nonpurging type involves that the individual during the current episode of bulimia nervosa has used other inappropriate compensatory behaviors, such as fasting or excessive exercise, but has not regularly engaged in self-induced vomiting or the misuse of laxatives, diuretics, or enemas. Individuals with the purging type of bulimia nervosa usually have lower body weights, more symptoms of depression, and greater concern with body shape and weight than the individuals with nonpurging type. They are also more likely to exhibit fluid and electrolyte disturbances. The purging type are more likely to be multi-impulsive in that they are far more likely to have histories of substance abuse, shoplifting, and self-injurious behaviors.

Bulimia nervosa is prevalent in 1-3% of the population, and 25-30% of bulimic women have a history of anorexia nervosa. Bulimia nervosa affects 0.1-0.7% of males and 1.1%- 3.5% of females. Of people with bulimia nervosa, 10% are males. Furthermore, borderline personality disorder and bulimia nervosa are highly comorbid. There are several behaviors exhibited in bulimia nervosa that contribute to physical complications; vomiting results in gland enlargement and dental erosion; diuretic, sauna, and diet pill abuse can lead to brain hemorrhages, seizures, and irregular heartbeat; enema and laxative abuse leads to the dysfunction of the colon; thyroid hormone abuse can lead to both hyperthyroidism and death; abuse of ipecac, which has a very long half-life, can lead to its accumulation in the heart muscles and bones.

The medical complications that can result from bulimia nervosa are cardiac arrhythmias, sudden cardiac death, changes in blood pressure, gland enlargement, tears in the esophagus and bleeding/rupture, gastric dilation/rupture, loss of colonic function (may require colonic resection), osteoporosis, infertility, subcutaneous emphysema, aspiration pneumonitis, hypokalemic “contraction” metabolic alkalosis, dental enamel erosion, abnormal cytokine levels, and Russell’s sign. Russell,s sign is a prominent indicator of bulimia nervosa in which abrasions and scars occur on the back of the hands as a result of manual attempts to induce vomiting.

Bulimia nervosa is found to be familial in twin studies. Bulimia nervosa has a relatively stereotypical clinical presentation, sex distribution, and age of onset, which support the possibility of some biological vulnerability. There are moderate to substantial effects due to genetic factors. Chromosome 10 provides a significant linkage to bulimia nervosa while chromosome 14 provides a suggestive linkage. There are also increased rates of both anorexia nervosa and bulimia nervosa in relatives of individuals with bulimia nervosa. Bulimia nervosa, however, varies in presentation, but of the core features, frequency of vomiting has been shown to be reliable and heritable. Individual environmental factors provide moderate effects while shared environmental effects appear less important.

The most effective treatment for bulimia nervosa is cognitive-behavioral therapy (CBT). CBT focuses on challenging the patient’s thinking and beliefs about food and weight, changing eating behaviors, and developing problem-solving skills. CBT improves certain core symptoms such as body dissatisfaction, pursuit of thinness, and perfectionism. CBT is more effective than antidepressants. The benefits of antidepressants may diminish over time in a significant proportion of individuals who respond initially. Antidepressants also suppress bulimia nervosa symptoms in nondepressed individuals. While 30-70% of outpatients recover from bulimia nervosa, only 13-40% of inpatients recover, because inpatients have more severe cases of bulimia nervosa. After onset, disturbed eating behavior continues over the course of several years in a high percentage of clinic cases. After remission, approximately 30% of women experience relapse into bulimia nervosa symptoms.

Although the definition of recovery has not been formalized, individuals who have abstained from binge eating and purging for months or years are classified as recovered. Individuals who have recovered from bulimia nervosa continue to be overly concerned with body shape and weight, to engage in abnormal eating behaviors, and to experience dysphoric mood. Individuals tend to have greater than normal perfectionism, and their obsessional target symptoms are the need for symmetry and ordering/arranging. Pathological eating behavior and malnutrition tend to exaggerate these symptoms; however, these symptoms continue at a less intense level after recovery.

- TJM