What is an eating disorder that is marked by eating very large amounts followed by fasting?

Epidemiology

Bulimia nervosa is generally a syndrome seen in young women, afflicting approximately 1–4% of college-aged women in community samples, although it is also seen in older women (mostly with chronic or chronic, intermittent bulimia nervosa that had its onset in youth, but occasionally as a new onset syndrome) and in men. Indeed, the overwhelming majority of people with bulimia nervosa, over 90% in clinical samples, are female. This gender distribution is often regarded to be a result of a societal or cultural premium on feminine beauty that is transmitted to the young woman through either conscious or unconscious channels (most conspicuously via mass media). That eating disorders are more common in industrialized nations and in affluent individuals is consistent with the notion of environmental influences on the development of bulimia nervosa. That white women much more frequently develop bulimia nervosa and anorexia nervosa than black women is also taken to reflect the relatively higher value placed on thinness in the former culture. Black and white women are at roughly equal risk for binge eating disorder—that is, unrestrained eating—but white women are more likely to show compensatory fasting or purging behavior and concerns about body weight and shape. However, if a female—regardless of race—internalizes the view that slender beauty is ideal, body dissatisfaction, severe fasting, and even subsequent binge eating and full-blown bulimia nervosa may develop.

Impaired satiety, secretive eating, binge eating, postprandial vomiting, and other symptoms of abnormal eating are also surprisingly common in preschool children, although much more work is needed to understand and characterize these phenomena and their frequency.

Basic Information

Introduction

Bulimia nervosa (BN) involves three behavioral and cognitive components: binge eating, inappropriate compensatory measures, and body image disturbance. Binge eating is defined as (1) eating a large amount of food in a discrete amount of time which would be atypical of others in similar circumstances and (2) a sense of loss of control during these eating episodes. Binge-eating episodes are often followed by a negative emotional state, and often occur in response to stressors or after a period of fasting. The food consumed during binge-eating episodes is usually high in calories and often has fat content, for example, sweets. Research also suggests that the disorder has a significant financial cost (i.e., $1599.45 per year in the United States) associated with purchasing the food that patients consume during their eating episodes.

Compensatory behaviors can involve multiple methods including vomiting; laxative, diuretic, or enema misuse; fasting; or overexercising. DSM-IV suggests that binge-eating and purging behaviors occur in combination and at least twice weekly for 3 months. Body image disturbance is defined such that self-evaluation is unduly influenced by body shape and weight. These symptoms must not occur during the course of anorexia nervosa (AN), which is marked by maintenance of low weight.

BN can be specified in two ways: purging and nonpurging. Purging behavior includes vomiting, and misuse of laxative, diuretics, or enemas. Nonpurging BN is diagnosed when the patient only engages in fasting or overexercise.

BN includes ∼25.5% of outpatient eating-disorder (ED) diagnoses. Many ED patients tend to fall into the ED not otherwise specified (EDNOS) category, as many patients' symptoms do not meet the full criteria for BN. EDNOS is the most common ED diagnosis, constituting nearly 60% of outpatient ED cases. Given this large grouping which lacks specifying detail, many clinicians and researchers are looking to the DSM-V to define the diagnostic criteria for subgroups of EDNOS. A future direction for the next edition of the DSM may be to operationalize the amount of food needed to define an ‘objectively’ large binge-eating episode. Some ED patients report experiencing ‘subjective’ binge-eating episodes, wherein the amount of food consumed is not necessarily considered larger than what others would eat (e.g., two cookies); however, the patient reports a feeling of loss of control during the consumption of the food. Further research is needed to better understand the caloric differences between objective and subjective binge-eating episodes. Additionally, recent attention has been paid to ‘purging disorder,’ which is similar to BN but is marked by compensatory behavior in the absence of objectively large binge-eating episodes. Limited research has explored this disorder, which is currently classified as a form of EDNOS.

Abstract

Bulimia nervosa (BN) and drug addiction share common features, and BN is often treated as an addiction. However, there is an ongoing controversy about whether BN is a type of addiction. This chapter compares the neurobiological features of BN and drug addiction. The synthesis of the two bodies of research suggests that BN has more neurobiological similarities than differences with drug addiction. Specifically, similar to many addictive drugs, there is an elevation of ventral tegmental area (VTA) and nucleus accumbens (NAc) dopamine, VTA DAT binding/mRNA, and NAc D1 binding in animal models of BN. Sucrose bingeing in animal models of BN decreases D2 binding, which occurs for cocaine but not for other drugs. Both BN and drug addiction have similar adaptations in glutamate receptor expression, μ opioid receptor binding, and prefrontal cortex activity. There is a difference in the effectiveness of drugs that target glutamate to treat these disorders. Together, these results suggest that BN may be a type of addiction.

Bulimia Nervosa and Binge-Eating Disorder

Bulimia nervosa and binge-eating disorder are characterized by binge eating (i.e., ingestion of abnormally large amounts of food associated with a perceived loss of control of eating); in bulimia nervosa, binges are followed by inappropriate compensatory behaviors, such as self-induced vomiting or laxative abuse, with maintenance of normal weight. In binge-eating disorder, there is not compensation, so obesity develops. There is considerable evidence that some satiation signals are less potent in patients with bulimia nervosa. For example, food preloads decrease meal size less in patients with bulimia nervosa than in controls, patients with bulimia must eat larger amounts of food to produce equivalent self-reports of fullness, and food-stimulated CCK release is less in patients with bulimia nervosa than controls. There is also evidence that serotonergic processing of satiation signals in the brain is altered in patients with bulimia nervosa. All these abnormalities appear to resolve as bingeing decreases, however, suggesting that they are not the initial cause of bulimia. It is likely that they facilitate the maintenance of bulimia nervosa once it has begun and impede recovery from it. Thus, these are attractive candidates for development of physiologically or pharmacologically based treatments. The risk of both disorders is substantially higher in women (approximately threefold for bulimia nervosa and approximately twofold for binge-eating disorder). Binge-eating disorder, which was recognized more recently, urgently requires investigation as it has a strong statistical association with morbid obesity (i.e., BMI > 40).

States of Undernutrition: Bulimia Nervosa

Bulimia nervosa (BN) is another eating disorder characterized by irregular feeding patterns, specifically binge eating, in individuals of normal body weight, many of whom aspire to body weight far below normal. These episodes of binge eating are followed by periods of self-induced vomiting, laxative abuse, or extreme exercise, all driven by an abnormal body image. BN affects approximately 2% of the general female population and approximately one third of patients with BN who present for treatment have a history of anorexia. Both anorexia and bulimia are more common in patients with coexisting low self-esteem, depression, and anxiety.242 Disturbances in the reproductive axis can be seen in patients with bulimia, but they do not define the condition, as in anorexia. Amenorrhea occurs in 30% of patients with bulimia.276 Approximately half of women with bulimia show hypogonadotropic hypogonadism and no evidence of follicular development associated with decreased LH pulse frequency,277,278 whereas others have normal gonadotropin secretion and normal follicular development but impaired luteal-phase progesterone levels.279 Patients with purging behaviors showed more severe reductions in LH responses to GnRH infusion than nonpurging patients with bulimia and control subjects.280 As in women with anorexia, serum cortisol is higher in bulimic women than in control subjects,278,281 possibly related to increased CRH stimulation.

Bulimia

BN is characterized by weekly episodes of binge eating and a subsequent compensatory behavior for 3 months. Objectively, binge eating is considered consuming a large amount of food within a 2-h period while experiencing a lack of control over what or how much one is consuming. This binge is followed by a compensatory behavior (e.g., vomiting, use of diuretics or laxatives, excessive exercise, fasting). Individuals with bulimia typically overvalue shape and weight. Key to a diagnosis of bulimia is that it cannot occur during a period of anorexia. If someone is underweight, meets all criteria for AN, and engages in binging/purging, this is binge/purge-type AN, not bulimia.

The epidemiology of bulimia is subject to the same adult bias as studies of the epidemiology of anorexia. Swanson and colleagues3 found a prevalence rate of 0.9%; however, rates range from 0.10% to 1.1% in other studies.4,5,12 Bulimia does appear to be more common in females, specifically females who identify as Hispanic. Like anorexia, bulimia begins in adolescence. Although some research indicates that bulimia has a later age of onset than anorexia,13 other reports indicated that the median age of onset is 12.4 years of age.3 The majority of individuals with bulimia engage in two or more types of compensatory behaviors.14 Males are more likely to engage in excessive exercise. In adults, there is some evidence that males will exercise not to compensate for calories consumed during a binge but rather to reduce fat and increase muscle definition.15 Bulimia does appear to be more common in females; however, the rates in boys are not regularly reported. The female to male ratio for bulimia has ranged from 3:1 to as high as 25:1.16

Impairment is high in bulimia, with 78% of adolescents in the National Comorbidity Study Replication reporting impairment, 10.7% of these adolescents reported severe impairment. Youth with BN also reported that their eating disorder negatively affected their social and family relationships.3 Comorbidity rates are approximately 83% in bulimia. Depression is the most common comorbid condition.10 Impulsive and self-harm behaviors are often observed.17 Over half affected individuals express suicidal ideation; of those 25.9% have a plan and over a third (35.1%) of adolescents with bulimia have attempted suicide.3 These rates are the highest among adolescents with eating disorders and higher than in adolescents with other psychiatric diagnoses.18 Only 60% of adolescents and their families seek out treatment, and 21.5% seek out specialty treatment.3

DESCRIPTION

Bulimia is an eating disorder. A person with bulimia eats larger amounts of food (called binging) than most people would eat in a short time. Then they purge (such as with self-induced vomiting or other methods) to rid themselves of the food and avoid weight gain. They may also use nonpurging methods such as fasting or exercising too much. There can be numerous symptoms including behavioral, physical, and emotional effects. Bulimia affects both sexes (women much more than men). It often starts in the teen years.

Clinical, prevention, intervention, and/or policy takeaways

Bulimia nervosa (BN) is a serious disease that usually begins in adolescence or early adulthood and can be associated with significant risk of morbidity and mortality due to medical complications and psychiatric comorbidities. Individuals with BN frequently hide their symptoms due to guilt or shame, minimization of the consequences of the disease, and ambivalence about the treatment. Screening for eating disorders (EDs) is recommended in adolescent health care. When BN is suspected, the clinical evaluation should include a comprehensive history, a physical examination, and laboratory tests and can be supplemented with other assessment tools. The diagnosis in younger patients may be challenging due to age-related developmental issues. Adolescents with BN should receive treatment as early as possible to improve their prognosis, which includes addressing nutritional and psychological issues, use of psychotropic medication for ED when indicated, and management of medical complications and psychiatric comorbidities. Treatment should involve a multidisciplinary team that is developmentally aware, sensitive, and skilled in the care of adolescents with EDs and include the parents. The majority of patients with BN can be treated as outpatients.

6.27.2.1.2 Clinical Features of Bulimia Nervosa and Bulimia Nervosa OSFED Type

Bulimia nervosa is a later 20th century feeding and eating disorder. Early conceptualizations of “bulimia” in the DSMIII (American Psychiatric Association, 1980) were closer to that of the contemporary diagnosis of binge eating disorder. Bulimia nervosa as currently defined first appeared in the DSMIIIR (American Psychiatric Association, 1987).

The cognitive criteria for the bulimia nervosa are similar to that for anorexia nervosa in requiring the person to have an undue endorsement of weight and shape concerns to their view of themselves, i.e., overvaluation. Specifically, people with bulimia nervosa also have regular weekly episodes of binge eating which, in the DSM5, is defined as eating an unusually large amount of food over which the person has a sense of loss of control that most usually occurs within a defined time point or time period. Binge episodes are followed by compensatory behaviors such as self-induced vomiting or purging with laxatives or diuretics or, in the non-purging form, extreme compulsive exercise or dietary restriction to the point of fasting for up to 8 h or more. Severity is specified according to average weekly frequency of compensatory behaviors: mild with 1–3 behaviors; moderate 4–7 behaviors; severe 8–13 behaviors; and extreme 14 or more episodes of weekly compensatory behaviors. Bulimia nervosa also has specifiers for full and partial remission status where all or some diagnostic criteria are not met for a sustained time period, respectively. Bulimia nervosa OSFED is where all criteria are met except the frequency or duration (at least 3 months) of binge-purge episodes.