A person with bulimia nervosa exhibits a preoccupation with food and often binges in secret. A binge is an amount of food that is definitely larger than most people would eat during a similar period of time and under similar circumstances (e.g., most people will overeat on holidays). Bingers also exhibit a lack of control over eating during the episode, calorie intake varying from 3,000 to 40,000 per episode. Incidence of this disorder is unknown, since it is secretive and is kept hidden due to fear or shame. Bulimia nervosa often begins in teenage years, but recorded incidences range from ages 5 to 70.
Binge episodes are followed by several forms of purging. Vomiting can be induced by inserting a finger or other object down the throat. After some time vomiting may no longer need to be induced. The person will check that all the intake has been vomited before purging is completed. Feelings immediately afterward are relief, power, of being able to overeat but avoid the consequences, of “winning,” and of fooling everyone. One young woman reported, “It’s the only thing my father can’t control.” These feelings are positively reinforcing and help to explain why the disorder continues. However, negative feelings such as self-depreciation, self-hatred, fear of discovery, Guilt, and being out of control, follow the positive ones. Bulemics often promise never to do this again.
Other forms of purging include laxatives (typically 2 to 30 laxatives per use), diuretics, diet pills, or enemas. These methods do not achieve weight loss, but still the sense of getting rid of the intake is satisfying and reinforcing. Nonpurging methods include excessive exercise (up to five hours per day), which can be rationalized as fitness. Fasting, an attempt to make up for the excessive intake, is self-defeating in that it triggers binge eating again when the person feels starved.
Physical ramifications of binging followed by purging can include swollen salivary glands, broken blood vessels in the eyes, ruptured stomach, esophageal tears, dehydration, electrolyte imbalance (which jeopardizes heart function), and malnutrition. Because vomit erodes the enamel on the inside of the teeth, one eight-year bulimic reports dental repairs costing $10,000.
Bulimia nervosa has several causative factors. One biological factor points to serotonin in the brain and its regulation of satiety and food preferences as well as in regulation of impulses. Approximately 85% of bulimic patients suffer from hypoglycemia (low blood sugar), which may contribute to the urge to binge; over time the behavior develops addictive qualities. A multilevel model for the etiology of bulimia nervosa includes social, cultural, family, and personal factors: society overvalues thinness, and obesity is highly stigmatized; bulimic families express greater anger, aggression, and conflict (without conflict resolution skills), indirect communication, lack of support, and lack of economy; overattention to food and weight in the family (degree of symptoms is associated with occurrence among mothers and sisters); overconcern with pleasing others; strong peer group influences to be attractive (thin), to gain approval of other females, and to attract boyfriends; sense of ineffectiveness and low interoceptive awareness, generating high anxiety; a disconnection from unpleasant feelings by diverting attention to food. Bulimics may display other impulsive behaviors such as drinking, sexual promiscuity, kleptomania, spending sprees, and drug use.