The essential features of Bulimia Nervosa are binge eating and inappropriate compensatory methods to prevent weight gain at least twice a week for at least three months. The self-evaluation of people with Bulimia Nervosa is excessively influenced by body shape and weight. A binge is defined as eating in a discrete period of time (usually less than two hours) an amount of food that is significantly larger than most people would eat under similar circumstances. Although the type of food consumed during binges varies, it typically includes sweet, high-calorie foods such as ice cream or cake. However, binge eating is characterised more by the abnormality in the amount of food consumed than by a craving for a specific food.
Individuals with Bulimia Nervosa are typically ashamed of their eating problems and try to conceal their symptoms, hence behaviours usually occur in secrecy. The binge often continues until the person is uncomfortably, even painfully, full. Binge eating is typically triggered by negative mood states, interpersonal stressors, intense hunger following dietary restraint, or negative feelings related to body weight, body shape, and food. Binge eating may reduce negative mood states temporarily, but self-loathing and depressed mood usually follow soon after. An episode of binge eating is also accompanied by a sense of lack of control. Some sufferers describe a dissociative quality during binge episodes and/or difficulty stopping a binge once it has begun.
Another essential feature of Bulimia Nervosa is the recurrent use of inappropriate behaviours to compensate for binge eating. The most common compensatory technique is the use of vomiting after a binge, the immediate effects of this includes relief from physical discomfort and reduction of fear of weight gain. Other purging behaviours utilised include the misuse of laxatives or diuretics, while another compensatory behaviour involves the use of excessive exercise to neutralise the calories consumed during an episode of bingeing.
Individuals with Bulimia Nervosa place an excessive emphasis on body shape and weight, and these factors are typically the most important ones in determining self-esteem. People with this disorder may closely resemble those with Anorexia Nervosa in their fear of gaining weight, in their desire to lose weight, and in the level of dissatisfaction with their bodies.
The following subtypes are used to specify clinical features of the current episode of Bulimia Nervosa:
- Purging Type: The person has regularly engaged in self-induced vomiting or the misuse of laxatives, diuretics, or enemas during the current episode.
- Nonpurging Type: The person has used other inappropriate compensatory behaviours, such as fasting or excessive exercise, but has not regularly engaged in self-induced vomiting or the misuse of laxatives, diuretics, or enemas during the current episode.
Associated Features and Disorders
Individuals with Bulimia Nervosa typically are within the normal weight range. There is an increased frequency of depressive symptoms and low self-esteem in people with Bulimia Nervosa. In most sufferers, the mood disturbance begins at the same time as or following the development of Bulimia Nervosa, and individuals often attribute their mood disturbances to Bulimia Nervosa.
However in some sufferers, the mood disturbance clearly precedes the development of Bulimia Nervosa. There may also be an increased frequency of anxiety symptoms (eg. fear of social situations) which often abate following effective treatment of Bulimia Nervosa. Substance abuse or dependence, particularly involving alcohol and stimulants, occurs in about one-third of sufferers.
Stimulant use often begins in an attempt to control appetite and weight. Preliminary evidence suggests that individuals with Bulimia Nervosa, Purging Type, show more symptoms of depression and greater concern with shape and weight than those with Bulimia Nervosa, Nonpurging Type (Garner and Garfinkel, 1997; APA, 2000).