Anorexia nervosa and bulimia nervosa are the two major eating disorders. They are complex syndromes with considerable psychiatric and medical comorbidities. Current diagnostic criteria for anorexia nervosa and bulimia nervosa from DSM-IV (1) are shown in Tables 5.7.2.1 and 5.7.2.2. For those patients who have serious problems with eating behavior but do not fall into the diagnostic categories of anorexia nervosa or bulimia nervosa, the DSM-IV has designated a category of “Eating Disorder Not Otherwise Specified” (EDNOS). Most cases of eating disorders have an onset during adolescence.

There are four major criteria which define anorexia nervosa. The first criterion is a guideline for defining weight loss, since there is no specific amount of weight loss associated with the other symptoms that constitute anorexia nervosa. Therefore, an adult is considered “underweight” if the individual weighs less than 85% of a weight that is considered normal for that person’s age and height. For children up to the age of 18, pediatric growth charts should be used. Some children may not have weight loss but still weigh less than expected weight because they have failed to make weight gains during a growth in height.

There is no consensus on how weight loss should be calculated, especially with adolescent patients. Some clinicians calculate weight loss below a normal weight for age and height and others figure the amount loss from an original baseline. Body mass index (BMI) is height in meters squared divided by weight in kilograms. This measure is a standard score that somewhat corrects for height and different body build. This index has the advantage of not being subjected to cultural influences. Generally, a BMI of less than 17.5 is regarded as being underweight. A BMI between 25 and 30 is considered overweight and over 30 is labeled obesity.

The second criterion, “intense fear of gaining weight,” is present even during emaciated states. Anorectic patients often deny this fear since they are resistant to treatment and thus, their fear of gaining weight must often be inferred by reports of their behavior which reveal rigorous attempts to prevent weight gain such as severe food restriction and exercising.

The third criterion, pertaining to body image disturbance, has evolved into a more complex concept. The significance of body weight and shape are greatly distorted in these individuals. Some feel globally overweight and others realize they are thin but feel certain parts of their body, especially the abdomen and thighs, are too fat. The distorted significance of body weight and shape is related to a feeling of being very ineffective. Losing weight and being thin is one area in which these individuals can be effective and in control. The latter undoubtedly influences their denial of the serious medical complications of their malnourished state.

The fourth criterion for diagnosis of anorexia nervosa in the DSM-IV is amenorrhea. In some adolescents who have never menstruated, the amenorrhea is primary and menarche is delayed by the anorexia nervosa. Amenorrhea can appear before noticeable weight loss has occurred (2). Because it is difficult to obtain an accurate history of menses and because of the great variation associated with weight loss in menses, some academicians are advocating abolishing this criterion.

There are two subtypes of anorexia nervosa: the restricting type and the binging-purging type. Studies have consistently demonstrated that impulsive behaviors including stealing, drug abuse, suicide attempts, self-mutilation and promiscuity are more prevalent in anorectic— bulimics compared with
anorectic restrictors. Those with anorexia binge-purge type also have a higher prevalence of premorbid obesity, familial obesity, debilitating personality traits, and specific medical complications compared with those anorexia restrictive type (3,4,5).

The criteria for bulimia nervosa are more arbitrary and less specific than the criteria for anorexia nervosa. There is no consensus on what constitutes a binge and how frequently bingeing must occur to warrant a diagnosis of this disorder. In the first criterion for bulimia nervosa in DSM-IV, binge eating is defined as eating more food than most people eat in similar circumstances and in a similar period of time. The sense of losing control is a significant subjective aspect that needs to be present. The second criterion, which is the recurrent use of inappropriate compensatory behaviors to avoid weight gain, usually means self-induced vomiting. However, bulimic patients often use cathartics for weight control and have an eating pattern of alternate binges and long fasting periods. The third criterion designed to address chronicity and frequency is not based on specific research but rather clinicians’ consensus for obvious impairment of functioning. The fourth criterion acknowledges that bulimia nervosa patients are also concerned about their body shape and weight and tend to place excessive estimation of their worth in terms of appearance. The fifth criterion of bulimia nervosa differentiates the latter from the binge-purge subtype of anorexia nervosa. The diagnosis of bulimia nervosa is also subtyped into a purging type for those who regularly engage in self-induced vomiting or use of laxatives or diuretics and a nonpurging type for those who use strict dieting, fasting, or rigorous exercise but do not engage in purging behaviors. Bulimia nervosa patients who do not purge tend to have less body image disturbance and less anxiety concerning eating compared with those who do (6).

Binge eating disorder is listed in the “Not Otherwise Specified” category of the DSM-IV for eating disorders. People with this disorder lack the compensatory weight-control behaviors and the overconcern with weight and shape (7). Field trials are being conducted to provide evidence as to whether binge eating disorder should be a specific diagnostic category.

Other examples of persons who are given an EDNOS diagnosis are those who vomit after eating small amounts of food but maintain a weight within a normal weight range and menstruate.

Disturbances of eating behavior were described in the Middle Ages. Well documented case reports of anorexia nervosa are found in the literature describing early Christian saints. Monastery documents record the severe starving behavior and binging episodes of Saint Catherine of Siena, along with the kind of reed she used to induce vomiting and the herbal cathartics she used for purging (8). Another example of this irreversible self-starvation in a fasting female saint is Princes Margaret of Hungary, who lived from 1240 to 1271 (9). She was the daughter of a king and was raised in a Dominican convent where she excelled in all of her studies and in the undesirable chores of the monastery. It is likely that biological vulnerability factors are similar in those dieting for sainthood during the Middle Ages and those dieting for thinness (attractiveness) in the twentieth century. In the seventeenth century both John Reynolds (10) and Richard Morton (11) described cases of typical anorexia nervosa symptomatology and distinguished them from consumption. In the nineteenth century Marcé (12), Sir William Gull (13) and Laséque (14) described additional cases of anorexia nervosa and recommended treatment. In the twentieth century the first major publication on anorexia nervosa was a book by Bliss and Branch (15) that presented endocrine studies as well as psychological descriptions of the disorder. A decade later Hilda Bruch (16) further articulated the psychology of anorexia nervosa in her phrase “the relentless pursuit of thinness” and “the paralyzing sense of ineffectiveness, which pervades all thinking and activities.” In 1979 Russell identified bulimia nervosa as a separate entity from anorexia nervosa (17). Subsequently it became apparent that there were young women who had the full syndrome of bulimia nervosa without a history of anorexia nervosa.

Most of the studies of incidence and prevalence of eating disorders have been conducted on limited populations and
countries. Thus, the true incidence and prevalence of anorexia nervosa and bulimia nervosa within various countries is not likely truly accurate. Some may be a closer approximation to reality. A recent incidence study conducted in Northeastern Scotland showed that between 1965 and 1991, there was almost a six-fold increase in the incidence of anorexia nervosa, from 3 per 100,000 per year to 17 per 100,000 per year (18). In a large representative sample of the Dutch population in Holland, Hoek (19) reported the incidence of bulimia nervosa as 9.9/100,000 per year during the period 1985/1886 and 11.4 during the period 1986–1989. In Rochester, MN, a study covering a 50-year span found an overall adjusted incidence for females of 14.6 per 100,000 per year; for men the corresponding figure was 1.8 (20). This study showed no change in the rates for females 20 years and older. Among 10- through 19-year-old girls, the incidence rates increased substantially from 1950 to 1984. In summary, when estimates are based on the population at large, the incidence of anorexia nervosa in industrialized countries is estimated at 8.1 per 100,000 per year.

Soundy et al. (21) found the community-based incidence of bulimia nervosa rose sharply from 1980 to 1983 and then remained relatively constant through 1990. The incidence rates of Rochester, MN during that decade were 26.5 per 100,000 per year for females and 0.8 per 100,000 per year for males. The mean age of onset for females is 23 years. Among 15- through 24-year-old adolescent girls and young women, it had become at least twice as common as anorexia nervosa.

Prevalence studies of eating disorders are more abundant and are easier to conduct. An average prevalence of anorexia nervosa in England, Sweden, and Scotland using strict diagnostic criteria was 0.28% of young females (18).

Over 50 prevalence studies of bulimia nervosa conducted between 1981 and 1989 had a fairly consistent prevalence rate of 1% for bulimia nervosa in adolescent and young adult women (22).

The male to female ratio for eating disorders in clinical samples lies consistently between 1:10 and 1:20 (19). The onset of anorexia nervosa is usually between the ages of 10 and 30, with 85% of all anorectic patients developing the illness between the ages of 13 and 20 (23). In one large sample study a bimodal distribution of age onset was found, with peaks at 14 and a half and 18 years (24). The stress of dieting may be greater at these times, during mid-puberty and at age 18, when adolescents are preparing to leave home for a job or attend college. Since attractiveness is equated with better acceptance, young women may be more concerned about their appearance when they are preparing to leave the safe and dependent home environment.

Two hallmark characteristics of patients with anorexia nervosa are denial of the seriousness of their illness and resistance to treatment, both of which make obtaining an accurate history and producing an effective treatment result a challenge. Anorectic individuals demonstrate their intense fear of gaining weight by their intense preoccupation with thoughts of food and irrational worries about fatness. They frequently look in mirrors to make sure they are thin and incessantly express concern about their appearance. They will take a great deal of time cutting up food into small pieces and rearranging food on their plates in order to eat less. An overwhelming feeling of inadequacy and ineffectiveness is a core symptom of all anorectics. Their success at losing weight is an impressive accomplishment and boosts their self-confidence. Obsessive compulsive behaviors often develop or become worse as their anorexia nervosa becomes more severe. Obsessions with cleanliness and an increase in cleaning activities and compulsive studying are commonly observed. Perfectionistic traits are common in the restricting type of anorexia nervosa patient.

Many adolescent anorectics have delayed psychosocial development and adults often have a markedly decreased interest in sex with the onset of anorexia nervosa.

There are important physiological differences between the two subtypes of anorectic patients. Most of the physiological and metabolic changes in anorexia nervosa are secondary to the starvation state or to purging behavior. These changes revert to normal with nutritional rehabilitation and the cessation of purging behavior.

In the patients with anorexia nervosa who engage in self-induced vomiting or abuse laxatives and diuretics, hypokalemic alkalosis may develop (Table 5.7.2.3). These electrolyte disturbances are associated with physical symptoms of weakness, lethargy and at times cardiac arrhythmias. The latter condition may result in sudden cardiac arrest, a cause of death in patients who purge. Mild elevation of serum liver enzymes may occur both in the emaciated anorectic phase and during refeeding. This reflects some fatty degeneration of the liver. Elevated serum cholesterol levels tend to occur more frequently in younger patients and return to normal with weight gain. Other common laboratory findings in emaciated anorexia nervosa patients are listed in Table 5.7.2.4. Laboratory findings present with bingeing and purging behavior are listed in Table 5.7.2.5.

Patients with bulimia nervosa should not be below 15% of the normal weight range. If they are, in most circumstances the correct diagnosis will be anorexia nervosa binge-purge subtype. Bulimia nervosa patients can be overweight. The sense of losing control of eating is a significant subjective aspect that occurs during binge eating. Abdominal pain or discomfort, self-induced vomiting, sleep, or social interruption usually terminate the bulimic episode, which is followed by feelings of guilt, depression, or self-disgust. Bulimic patients have a fear of not being able to stop eating voluntarily. Thus, ironically they may fast for long periods of time, lose control because of severe hunger, and then binge eat. Thus, they completely forgo a normal eating pattern and establish a routine of alternate binges and fasts. The food consumed during a binge usually has a high dense caloric content and a texture that facilitates rapid eating. Frequent weight fluctuations occur in bulimia nervosa but without the severity of weight loss present in anorexia nervosa. Most bulimic patients have difficulty feeling satiety at the end of a normal meal. They usually prefer to eat alone and at their homes. About one-fourth to one-third of these patients will have had a previous history of anorexia nervosa.

The majority of bulimia nervosa patients have depressive signs and symptoms. They have problems with interpersonal relationships, self-concept, impulsive behaviors, and also show
high levels of anxiety and compulsivity. Alcohol abuse and other drug dependency are not uncommon in this disorder. Bulimics will abuse amphetamines to reduce their appetite and lose weight. As is present in the binge-purge type anorectic patient, bulimia nervosa patients can have severe erosion of the enamel of their teeth, pathologic pulp exposures, loss of integrity of dental arches, diminished masticatory ability, and an obvious unaesthetic appearance of their teeth.

Parotid gland enlargement is associated with elevated serum amylase in bulimics who binge and vomit. Other complications of bingeing and purging behavior are listed in Table 5.7.2.3. Severe abdominal pain in the bulimic patients should alert the physician to a diagnosis of gastric dilatation and a need for nasal gastric suction, x-rays, or surgical consultation.

Cardiac failure may be caused by a cardiomyopathy from ipecac abuse. This is a medical emergency that usually results in death. Symptoms of pericardial pain, dyspnea, and generalized muscle weakness associated with hypotension, tachycardia, and electrocardiogram abnormalities should alert one to possible ipecac intoxication.

The development of anorexia nervosa and bulimia nervosa is best conceptualized within the framework of a multidimensional model, which states that these disorders begin with dieting behavior. Antecedent conditions such as social cultural influences, family environment, psychological or personality characteristics, and biological vulnerabilities impact on the dieting behavior to produce the full-blown disorders of anorexia nervosa and bulimia nervosa. As fasting behavior, weight loss, and binge/purge behavior continue, significant psychological and physiological changes occur. Some of these changes are strong secondary reinforcers that allow the process of fasting, weight loss, and binge/purge behavior to continue.

Secondary psychological reinforcement occurs when the young women initially receive compliments for their weight loss and later realize this is one area of their life in which they can be extremely effective and in control. Binge eating patients soon achieve a relief of anxiety during their binge eating even though that is followed by unpleasant feelings of guilt and depression. The physiological reinforcements are less precisely defined. For example, with the period of only 8 hours of fasting, there is an increased secretion of corticotrophin releasing hormone, which is a potent anorectic agent. This may be effective in assisting some anorectics to continue their decreased calorie intake. Exercising causes a release of norepinephrine and endogenous opioids, which may also reinforce a feeling of exhilaration.

Anorexia nervosa and bulimia nervosa seem to be predominately a “Western” disorder in that they are largely associated with the effects of industrialization and its resulting affluence. The Japanese health care system has been facing increasing numbers of patients with anorexia nervosa since World War II and the greater influence of Western values (25). Transcultural studies show that anorexia nervosa is rare in non-Western and poorly industrialized countries (26). When non-Westerners are exposed to Western ideals of thinness, they are significantly affected by the exposure. For example, Fichter et al. (27) found the prevalence of anorexia nervosa in Greek girls who are living in Germany and exposed to Western ideals of thinness was twice that of Greek girls who remained in Greece and were not exposed to Western values of body image. There have been suggestions that cultural differences in dietary habits, patterns of parent— child interactions, value orientation, and family structure may reveal more about the societal impact on the development of eating disorders (28).

The contributions of ethnicity to the development of eating disorders have been evaluated mainly by self-answering questionnaires rather than structured interviews. In a large cross-sectional study no differences among Asians, African Americans, Hispanics and Caucasians were found in mean levels of any eating disorder symptoms (29). The authors suggested the homogenization of cultural influences on body image and eating disturbances may account for the findings. Another study found no differences among Asian, Latino, and white adolescent girls and boys in dieting and restraint scores (30). However, a metaanalysis of 18 published studies from 1987 through 2001 found African-American women have fewer eating disturbances than do white women (31).

Ethnic variations in body image and self-perceptions, which are an integral part of some eating disorders, were found in several studies. In a comparison of African-American with Caucasian adolescent girls, a study by White et al. (32) showed the African-American girls had more favorable attitudes about physical appearance, reported less social pressures for thinness, and less tendency of basing self-esteem on body-related factors. In two other studies African Americans perceived a significantly different and larger body ideal for themselves than did Caucasians (33) and African-American men preferred significantly larger body size for women than Caucasian men (34).
In a study by Iyer and Haslam (35) racial teasing was found in women of South Asian decent to be associated with body dissatisfaction and disturbed eating. It is possible that the social and economic disadvantage present in non-Caucasian girls may sensitize them toward the culturally dominant body ideals and thus instill a risk factor for developing eating disorders. For example, a study of anorexia nervosa in Curacão found cases in only mixed ethnicity women who reported that thinness allowed them greater acceptance in the more affluent white community (36).

Feminist theories emphasize that women are indoctrinated into a belief system that overvalues feminine beauty, and in particular thinness. Women cannot achieve satisfactory self-esteem without attaining ideals that are impossible to fulfill. Eating disorders then become the adaptive response to the stress of demands that women conform to an impossible and oppressive social expectation. Some support for this hypothesis comes from a study done in Japan, which suggested eating pathology there may be linked to a conflict between traditional and modernizing roles for women (37).

Peer groups that tout slimness contribute to the risk for the development of eating disorders. In a study of 9- to 11-year-old girls, Wardell and Watters (38) found that greater exposure to older peers in school was associated with increased weight concern, dieting, and thinner size ideals. In another study sorority women were found to maintain a more rigorous dietary control than nonsorority women (39). Peer groups transmit and reinforce social values that perpetuate risk for body dissatisfaction and eating disorders (40). Higher rates of eating disorders are reported in sport activities in which leanness is valued, such as dance, gymnastics, and among jockeys (41). A study in England showed that girls from a higher social economic status environment reported greater exposure to weight loss and dieting by family and friends and the higher SES girls indicated a greater awareness of ideals of thinness (42).