(See also Introduction to Eating Disorders Introduction to Eating Disorders Eating disorders involve a persistent disturbance of eating or of behavior related to eating that Alters consumption or absorption of food Significantly impairs physical health and/or psychosocial... read more .)
Bulimia nervosa affects about 1.6% of adolescent and young women and 0.5% of men of comparable age. Those affected are persistently and overly concerned about body shape and weight. Unlike patients with anorexia nervosa Anorexia Nervosa Anorexia nervosa is characterized by a relentless pursuit of thinness, a morbid fear of obesity, a distorted body image, and restriction of intake relative to requirements, leading to a significantly... read more , those with bulimia nervosa are of normal or above-normal weight.
Pathophysiology of Bulimia Nervosa
Serious fluid and electrolyte disturbances, especially hypokalemia Hypokalemia Hypokalemia is serum potassium concentration 3.5 mEq/L ( 3.5 mmol/L) caused by a deficit in total body potassium stores or abnormal movement of potassium into cells. The most common cause is... read more , occur occasionally. Extremely rarely, the stomach ruptures or the esophagus is torn during a binge or purge episode, leading to life-threatening complications.
Because substantial weight loss does not occur, other serious physical complications that often occur with anorexia nervosa are not present. However, cardiomyopathy may result from long-term abuse of syrup of ipecac if used to induce vomiting.
Symptoms and Signs of Bulimia Nervosa
Patients with bulimia nervosa typically describe binge-purge behavior. Binges involve rapid consumption of an amount of food definitely larger than most people would eat in a similar period of time under similar circumstances (however, the amount considered excessive for a normal meal versus a holiday meal may differ) accompanied by feelings of loss of control.
Patients tend to consume sweet, high-fat foods (eg, ice cream, cake) during binge episodes. The amount of food consumed in a binge varies, sometimes involving thousands of calories. Binges tend to be episodic, are often triggered by psychosocial stress, may occur as often as several times a day, and are usually carried out in secret.
Binge eating is followed by compensatory behaviors: self-induced vomiting, use of laxatives or diuretics, excessive exercise, and/or fasting.
Patients are typically of normal weight; a minority are overweight or obese. However, patients are excessively concerned about their body weight and/or shape; they are often dissatisfied with their bodies and think that they need to lose weight.
Patients with bulimia nervosa tend to be more aware of and remorseful or guilty about their behaviors than those with anorexia nervosa and are more likely to acknowledge their concerns when questioned by a sympathetic clinician. They are also less socially isolated and more prone to impulsive behavior, drug and alcohol abuse, and overt depression. Depression, anxiety (eg, concerning weight and/or social situations) and anxiety disorders Overview of Anxiety Disorders Everyone periodically experiences fear and anxiety. Fear is an emotional, physical, and behavioral response to an immediately recognizable external threat (eg, an intruder, a car spinning on... read more are common among these patients.
Most physical symptoms and complications of bulimia nervosa result from purging. Self-induced vomiting may lead to erosion of dental enamel of the front teeth, painless parotid (salivary) gland enlargement, and an inflamed esophagus. Physical signs include
Swollen parotid glands
Scars on the knuckles (from repeatedly inducing vomiting by using fingers to trigger gag reflex)
Diagnosis of Bulimia Nervosa
Clinical criteria for diagnosis of bulimia nervosa include the following:
Recurrent episodes of binge eating (the uncontrolled consumption of unusually large amounts of food) that are accompanied by feelings of loss of control over eating and that occur, on average, at least once/week for 3 months
Recurrent inappropriate compensatory behavior to influence body weight (on average, at least once/week for 3 months)
Self-evaluation that is unduly influenced by body shape and weight concerns
Treatment of Bulimia Nervosa
Selective serotonin reuptake inhibitors (SSRIs)
Cognitive-behavioral therapy is the treatment of choice for bulimia nervosa. Therapy usually involves 16 to 20 individual sessions over 4 to 5 months, although it can also be done as group therapy. Treatment aims to
Increase motivation for change
Replace dysfunctional eating with a regular and flexible pattern
Decrease undue concern with body shape and weight
Cognitive-behavioral therapy eliminates binge eating and purging in about 30 to 50% of patients. Many others show improvement; some drop out of treatment or do not respond. Improvement is usually well-maintained over the long-term.
In interpersonal psychotherapy, the emphasis is on helping patients identify and alter current interpersonal problems that may be maintaining the eating disorder. The treatment is both nondirective and noninterpretive and does not focus directly on eating disorder symptoms. Interpersonal psychotherapy can be considered an alternative when cognitive-behavioral therapy is unavailable.
SSRIs Selective Serotonin Reuptake Inhibitors (SSRIs) Several drug classes and drugs can be used to treat depression: Selective serotonin reuptake inhibitors (SSRIs) Serotonin modulators (5-HT2 blockers) Serotonin-norepinephrine reuptake inhibitors... read more used alone reduce the frequency of binge eating and vomiting, although long-term outcomes are unknown. SSRIs are also effective in treating comorbid anxiety and depression. Fluoxetine is approved for the treatment of bulimia nervosa; a dose of 60 mg orally once/day is recommended (this dose is higher than that typically used for depression).
Bulimia nervosa involves recurrent episodes of binge eating followed by inappropriate compensatory behavior such as self-induced vomiting, laxative or diuretic abuse, fasting, or excessive exercise.
Unlike patients with anorexia nervosa, patients rarely lose much weight or develop nutritional deficiencies.
Recurrent self-induced vomiting may erode dental enamel and/or cause esophagitis.
Treat with cognitive-behavioral therapy and sometimes an SSRI.