Eating disorders are a spectrum of illnesses that have serious psychological and medical consequences, both in the short and long term. In the case of bulimia nervosa, the general trend is to binge, or eat profound quantities of food, and then use compensatory measures to remove calories and prevent weight gain. To understand bulimia, a number of topics must be explored, including the clinical definition, epidemiology, the signs and symptoms, treatment, and consequences.
The Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV) defines bulimia nervosa with the following four criteria. There are episodes of binge eating with a sense of loss of control. The binge eating is followed by compensatory purging behavior, such as self-induced vomiting, laxative, or diuretic abuse. The binges and compensatory behavior must occur a minimum of two times per week for at least three months. The individual must also have dissatisfaction with his or her body shape and weight.
Bingeing is described as eating, in a defined and self-limited amount of time, an amount of food that is larger than most people would eat during a similar time period and under similar circumstances. During this time, the person feels out of control with his or her eating, as though he or she cannot stop. Purging can take many forms and is an attempt to compensate for the extreme food intake during a binge. Purging can be achieved by self-induced vomiting, using laxatives, diuretics, or with excessive exercise. Bulimia is frequently divided into two subtypes: purging and nonpurging. Purging involves those who induce vomiting, or use laxatives, diuretics or enemas to remove calories, whereas those who use excessive exercise or periods of fasting to compensate for calorie intake fall into the nonpurging type. Nonpurging is more rare and accounts for only 6 to 8 percent of bulimic patients.
There is great difficulty in accurately evaluating the epidemiology of eating disorders due to changes in diagnostic criteria over time, the reliance on self-reporting, and the tendency for those affected to deny the disorder. Bulimia nervosa was first described in 1977, at the Royal Free Hospital in London and was recognized as an eating disorder by the American Psychiatric Association in 1980. It is estimated that between one and two million women in the United States would meet the criteria for bulimia nervosa. Over 90 percent of bulimic patients are female. There are two peaks in incidence of bulimia, at ages 14 and then at 18, although presentation can be into adulthood.
There is no medical consensus on the etiology of eating disorders including bulimia nervosa. Most models include psychological, biological, family, genetic, environmental, and societal factors. These forces can cause a decreased sense of self-esteem, body image, or self-control. There are several more specific factors that may be influential in the development of bulimia and other eating disorders. For example, some literature suggests that an important predictor of eating disorders is dieting during adolescence. In addition, if there is a preoccupation or obsession with thin body image or if one feels a social pressure to be thin, this may be associated with the development of eating disorders. Activities that emphasize body shape, such as gymnastics, dance, and cheerleading may also influence the development of eating disorders.
Bulimia nervosa also has a familial component, as the incidence is increased if a first-degree relative also has bulimia. In addition, twin studies of eating disorders in the United States and Europe have shown between 28 and 83 percent heritability for bulimia nervosa and binge-eating disorders. These studies avoid the bias of specific household environmental factors, but do not eliminate overarching societal pressures or influences. Feminist psychology theory has suggested that societal pressure to be “superwomen” in the setting of Western society can predispose women to develop eating disorders. There have been conflicting results regarding the association of eating disorders and sexual abuse. The rates of sexual abuse among patients with bulimia were found to be higher than healthy controls, but these increased rates of sexual abuse were similar to that seen among other psychiatric populations. Basic science research also suggests that there is a disturbance in neurotransmitter balance in patients with bulimia, particularly with serotonin. There may also be differences in the role of appetite and satiety in these patients. The release of cholecystokinin, a hormone that influences the sensation of fullness, is low at baseline in bulimic patients, and does not rise to as high levels after a meal.
Patients with eating disorders such as bulimia have higher rates of comorbid psychiatric disorders, such as obsessive-compulsive personality traits when they are children. In addition, there is a higher rate of substance abuse in those with eating disorders. In particular, alcohol problems have a higher prevalence in those with bulimia nervosa.
Bingeing episodes may be either gradual or acute. Gradual episodes are preceded by plans to binge, including purchasing or preparing the food, whereas acute binging episodes are urgent and are immediately fulfilled by any food that is available. These binging episodes are most often done in secrecy. Once a binge has been initiated, the patient experiences a feeling of loss of control, food is consumed rapidly, and the appetite seems insatiable. These episodes may last for up to an hour and are ended when the patient is unable to physically eat any more, and may experience nausea, bloating or pain, as well as feelings of guilt and shame. In contrast to those with anorexia, patients with bulimia can acknowledge that their behavior is abnormal but conceal the disease. These binges may occur several times a day, but must occur at least two times per week in a three-month period to meet the definition.
Removal of calories to prevent weight gain is most commonly achieved by induction of vomiting by irritating the back of the throat with a finger. In severe cases, those with bulimia may not need to induce vomiting and it becomes almost reflexive and food regurgitates automatically. Bulimics also employ laxatives or diuretics to stimulate rapid bowel movements or loss of fluid weight via urine. In addition to physically removing the binged food from the body, bulimics may also exercise to eliminate calories.
A bulimic patient usually has a normal body weight, or may be slightly overweight, which is a marked difference between bulimia and anorexia. The physical consequences of bulimia include acute gastric dilation during a binge episode, with acute and severe abdominal pain, which may lead to gastric rupture if untreated. Frequent vomiting may lead to erosion of the teeth and dental caries, tooth discoloration and increased temperature sensitivity, the patient’s knuckles and fingers may have lesions or scratches from inducing vomiting. Vomiting may also cause irritation of the esophagus, causing esophagitis or esophageal tears. The parotid glands, or salivary glands located in front of the ears, may swell secondary to constant irritation from vomiting. Electrolyte imbalances such as low potassium may also result from the constant vomiting, laxative, and diuretic use. Laxative abuse may also lead to irritation of the intestinal lining and rapid transit of stool through the intestines, leading to pain, the development of hemorrhoids, rectal bleeding, or rectal prolapse. Dehydration may lead to dizziness, fainting, and thirst.
Women who are affected by bulimia nervosa have amenorrhea, or lack of menstrual cycles and subsequent infertility. If they do conceive, they are at higher risk of having a miscarriage.
As with all eating disorders, treatment for bulimia nervosa involves an interdisciplinary care approach. This includes medical personnel, dieticians with experience with bulimia, and mental health professionals. For bulimia in particular, a combination of antidepressant medication and psychotherapy in combination with cognitive behavioral therapy has been shown to be the most efficacious. In contrast to anorexia nervosa, most treatment for bulimia can be managed on an outpatient basis. The medical staff can manage acute electrolyte abnormalities and dehydration secondary to frequent vomiting. They can also monitor weekly weigh-ins to assess weight gain and monitor vital signs. The dietitian can provide education about a healthy diet and can work with the patient to develop behavior change around eating habits. They can establish caloric requirements and can help to determine goal weight. The mental health professional works with both the patient and his or her family to address underlying issues that may have precipitated the eating disorder. The mental health provider can address comorbid affective disorders, such as depression, which often accompany eating disorders, and can screen for self-injurious behavior, which is common in those with eating disorders. Medical and mental health professionals must also address comorbidities, such as alcohol abuse.
Cognitive behavioral therapy emphasizes the relationship between thoughts and feelings to behavior, and helps the patient to recognize cues that can trigger binge eating. This can assist in managing anxiety, and can lead to the development of coping strategies. One facet of the disorder that should be addressed is the feeling of loss of control that accompanies the bingeing sessions, as well as the self-deprecating thoughts and distorted body image. The second stage of treatment involves understanding balanced and healthy eating habits. The final goal of cognitive behavioral therapy involves the maintenance of new, learned eating behavior. Therapy for bulimia has been conducted successfully on an individual basis and in group therapy, and may be used via outpatient treatment or in daytime therapy sessions.
In combination with the cognitive behavioral therapy and psychotherapy, medication has been shown to be more successful in the treatment of bulimia nervosa than other eating disorders. Pharmacotherapy often consists of antidepressants, such as tricyclic antidepressants and selective serotonin reuptake inhibitors. Antipsychotic medicines are also used, though in lower doses than that used to treat schizophrenia. In addition, the antiepileptic medicine topiramate and the selective serotonin antagonist ondansetron may also be helpful in reducing the urge to binge eat.
The hospitalization of patients with bulimia is considered in cases of severe malnutrition, dehydration, or electrolyte abnormalities; instability in vital signs such as heart rate or rhythm; arrest of normal growth, puberty, or development; uncontrollable bingeing or purging; and medical complications such as seizures or psychiatric emergencies such as suicidal ideation.
Little data exist on the long-term recovery and survival of a person with bulimia nervosa. It has been suggested that as the follow-up treatment time extends, there is a decline in the proportion of women that meet criteria for bulimia. Nearly half of all bulimic patients will remain symptomatic at 6 years after diagnosis, and in studies with 10 years of follow-up, 30 percent of women continue to binge and purge. More recent data also suggest that for bulimia nervosa, a significant factor in long-term mortality is the incidence of suicide.
Anorexia Nervosa; Eating Disorders and Athletes; Eating Disorders and Gender; Eating Disorders and Obesity; Eating Disorders in School Children; Sexual Abuse and Eating Disorders.
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