By Dr. Blackman, MA, MB, BCh, FRCPC
This is the third of a series of articles on Eating Disorders, and is Part 1 of two papers on Bulimia Nervosa. This first paper deals with the background and etiology of this syndrome. Bulimia is an under-diagnosed syndrome and the cause of significant morbidity especially in the female adolescent and young adult population. As will be discussed later, bulimia has both a historical and modern perspective. The authors consider Bulimia Nervosa to be on a continuum of eating disorders ranging from starvation syndromes to obesity.
"Uncontrolled recurring episodes of binge eating and self-induced vomiting and/or abuse of laxatives and diuretics in order to prevent weight gain" is the description used to describe the condition Bulimia Nervosa. The term Bulimia is derived from the Greek words "bous" meaning ox, and "limos" meaning hunger (Hsu 1990, pg 1, and Brownell & Fairburn 1995, pg 145).
Like its counterpart, Anorexia Nervosa, individuals with bulimia are excessively pre-occupied by their weight and body image. However, while the anorexic generally restricts food intake and hence loses weight, the bulimic patient, despite the cycle of bingeing and purging, may be at a reasonable or above normal weight.
Bulimia has been described since ancient times. Greek authors described the behaviors of cults as encouraging self-induced vomiting. (Giannini & Slaby 1993, pg 18).
The Egyptians believed that diseases came from food, and purged on a monthly basis, and the Romans had "vomitoriums". The wealthy Romans gave elaborate banquets during which twenty or more courses were consumed. To accommodate this, purging between courses was instituted as socially acceptable behaviour. These vomitoriums had "fountains, scented water, and flowers.…providing a pleasant environment for the guests to purge themselves of previous courses". The guests were then washed and cleaned by slaves and escorted back to continue with the meal. (Giannini & Slaby 1993, pg 18).
During the Middle Ages, religious authorities considered gluttony a mortal sin. Self-induced vomiting was allowed as penance. Forced emesis was also practiced among monks to control sexual drives and sharpen intellect.
The first known clinically description of bulimia is that of James who in 1743 defined "true boulimus, which was characterized by intense pre-occupation with food and overeating at very short intervals terminated by vomiting". Motherby (1785) distinguishes between three types of bulimia. These include "bulimia of pure hunger, bulimia associated with swooning, and bulimia terminated by vomiting". (Alexander-Mott 1994, pg 17).
Cases of bulimia approximating modern day criteria did not begin to appear in the literature until the 1930's. The word bulimia was re- introduced by John Trevisa in 1938 (Giannini & Slaby 1993 and Alenander-Mott & Lumsden 1994). The increased incidence of bulimic behaviour in the 1970's finally warranted the acknowledgment of Bulimia Nervosa as a distinct disorder in 1980 in the DSM III.
DIAGNOSIS OF BULIMIA NERVOSA
In the current issue of the Diagnostic Manual of the American Medical Association, (DSM IV), the criteria for the diagnosis of Bulimia Nervosa are as follows:
A) Recurrent episodes of binge eating. An episode of binge eating is characterized by both of the following:
(1) Eating, in a discrete period of time (e.g. within any 2 hour period), an amount of food that is definitely larger than most people would eat during a similar period of time and under similar circumstances.
(2) A sense of lack of control over eating during the episode (e.g. a feeling that one cannot stop eating or control what or how much one is eating)
B) Recurrent inappropriate compensatory behavior in order to prevent weight gain, such as self-induced vomiting; misuse of laxatives, diuretics, enemas, or other medications; fasting; or excessive exercise.
C) The binge eating and inappropriate compensatory behaviors both occur, on average, at least twice a week for 3 months.
D) Body shape and weight unduly influence self-evaluation.
E) The disturbance does not occur exclusively during episodes of Anorexia Nervosa.
Bulimia can also include two subtypes. Bulimia that includes the purging type characterizes those individuals who engage in repeated episodes of self-induced vomiting or misuse of laxatives and diuretics. Bulimia that includes the nonpurging type characterizes those individuals who do not engage in self-induced vomiting or the misuse of laxatives and diuretics but actively engage in fasting or excessive exercise to prevent weight gain.
Bulimia Nervosa usually begins in late adolescence or early adulthood. Ninety percent of all individuals suffering from bulimia are women, while only an estimated five to ten percent are men (Alexander-Mott & Lumsden 1994). The frequency of Bulimia Nervosa ranges from 3.8% to 19% among college-age women and from 3% to 8.3% among high school women (Alexander-Mott & Lumsden 1994). The literature cautions, however, that these prevalence rates may be an underestimation as many sufferers of bulimia go for many years undiagnosed and undetected. Furthermore, the incidence of Bulimia Nervosa appears to have increased within the past several years It is unknown if this increase is a true reflection in the rise of frequency or if it merely reflects better reporting.
Research findings suggest that individuals who suffer from Bulimia Nervosa have associated personality and behavioral problems. Weiss and Ebert (1983) compared fifteen individuals who met the DSM III criteria for Bulimia Nervosa against fifteen individuals from a community sample. They found that those individuals suffering from bulimia reported significantly higher rates of psychopathology in a number of areas including, "somatisation, obsession-compulsion, interpersonal sensitivity, depression, anxiety, anger, phobic anxiety, paranoid ideation, and psychotism". They also reported "greater external loss of control, greater fear of fat, and more anxiety in situations related to eating than controls" (Alexander-Mott & Lumsden 1994, pg 167). Beumont (1995) also found preexisting personality difficulties, and difficulties in interpersonal relations, impulse control and substance abuse. Beaumont also differentiated bulimics from anorexics who are characterized as "usually more reserved, introverted, inhibited, and obsessional" (Brownell & Fairburn 1995, pg 157). However, both anorexics and bulimics have been found to be perfectionists and to have high self-expectations.
In an attempt to prevent weight gain, bulimics usually follow a strict diet and avoid high calorie foods. However, as their restrictive diet becomes more difficult to follow and with their increasing preoccupation with food, episodes of gorging soon become established. Soon after the gorging behavior begins, self-induced vomiting begins as well as purging with laxatives and diuretics. The usual method of inducing vomiting is by inserting the finger down the throat but, as the bulimic purges on a more regular basis, they learn to vomit at will. (Brownell & Fairburn 1995, pg 156). Bulimic episodes are often planned to occur when chance of discovery is remote. The binge foods are usually sweet, fatty, high-calorie foods with the binge lasting anywhere from thirty minutes to an hour. Some bulimics will ingest large amounts of food within minutes while others may engage in "picking" behavior, taking in small quantities at a time (i.e. a teaspoon of ice-cream, a small piece of cake, or a portion of cheese), but continuing this "picking" for hours until they have ingested thousands of calories." (Brownell & Fairburn 1995, pg 156)
The binge-purge cycle affects every aspect of a bulimic's life. Not only does it cause health problems, but it interferes with interpersonal relationships and performance at school and/or work. The bulimic often feels ashamed of the behavior and becomes overwhelmed with guilt, shame and remorse. Because bulimics spend most of their time planning and creating situations where they can be alone to binge, they isolate themselves from family and friends which lead to further solitude. (Alexander-Mott & Lumsden 1994, pg 169).
The specific etiology of bulimia is not yet known but, as in anorexia and related food disorders, a multiplicity of factors appear to be involved requiring the interaction of biological, psychological and psychosocial areas.
Biologically based theories hypothesize that bulimia is the result of the dysfunctional regulation of neuroendocrine mechanisms in the hypothalamus. Two important regions in the hypothalamus effect feeding behaviors. The ventromedial hypothalamus contains a satiety center and a feeding center exists in the lateral hypothalamus. In animal experiments, stimulation of the ventromedial hypothalamus (satiety center) suppresses eating while hyperphagia and obesity occurs if this center is damaged. The opposite is true with the lateral hypothalamus. When this center is stimulated, there is increased eating while eating is suppressed once this center is damaged. Thus, "the satiety center is thought to coordinate the stop-feeding response; the feeding center integrates the start-feeding signal" (Giannini & Slaby 1993, pg 46).
The neurotransmitters Norepinephrine, Serotonin, and Dopamine are found in the hypothalamus and have been identified as having an important role in the regulation of food intake. When Norepinephrine is released in the lateral hypothalamus (feeding center) eating is suppressed. The same is true with Serotonin. When Serotonin is released in the ventromedial hypothalamus (satiety center) eating is again suppressed. Depletion of Serotonin results in hyperphagia and obesity, while Norepinephrine inhibits the satiety center increasing eating behaviors. (Giannini & Slaby 1993, pg 46).
It has also been hypothesized that bulimia has a biological basis by examining the relationship between bulimia and affective disorders. Pope and Hudson (1985) reported that "80% of the bulimic patients they have studied have had major affective disorder at some point during their lifetime" (Alexander-Mott & Lumsden 1994, pg 174). Some authors report that higher rates of depression are found among family members of bulimic patients and that some bulimics respond positively to treatment using antidepressant medication. However, it is also possible that the pathological eating behaviour leads either biologically or psychologically to depression. (Brownell & Fairburn 1995, pg 157).
From a psychosocial perspective bulimia is related to a society which stresses thinness and physical appearance related directly to self-esteem. This is especially apparent amongst females. Whether as a result of advertising that equates slimness with popularity or identification with popular media figures, young girls are becoming more and more preoccupied with their looks and body weight. Some authors have maintained that this is due to problems especially in regards to women's role in society while others do not see a sexual bias, but rather an increase in narcissistic preoccupations.
Baskind-Lodahl (1985) maintains "that a central issue in the development of eating disorders is the struggle in which women find themselves immersed when attempting to live up to an ideal of femininity that deprives them of an identity of their own" (Bendfeldt-Zachrisson 1992, pg 66). Thus, women's obsessions with their bodies are directly related to the expectations that society has on physical appearance and a "svelte figure has become an ideal to be anxiously pursued" (Bendfeldt-Zachrisson 1992, pg 67).
Orbach (1985) attributes the increase in incidence of eating disorders as a direct result to the development of the consumer society. Along "with reification of products on the market, sexuality has been made a commodity" (Bendfeldt-Zachrisson 1992, pg 67). The body has become a "permissible form of self-expression and self-involvement". (Bendfeldt-Zachrisson 1992, pg 68).
Psychological theories of bulimia reflect the full gamut of psychological theories in general. Traditional psychoanalytic approaches equate bulimia to repressed sexuality related to oedipal strivings. Object relations theory stresses problems in early mother-child separation individuation which leads to emotionally directed eating patterns. The bulimic rebels against the mother by taking control of eating patterns.
Other psychodynamic theories are less symbolic and focus more on the family dynamics. The belief is that the parents are not happy as a couple and displace their dissatisfaction and disappointment onto their child. The child is drawn into the conflict and is bombarded with unrealistic expectations. "Their displaced and excessive expectations with regard to the child also revolve around eating, food and body appearance" (Bendfeldt-Zachrisson 1992, pg 65).
In summary, Bulimia Nervosa can be viewed as a modern syndrome with some ancient origins. Bulimia has increased significantly in recent years consistent with societal expectations equating positive self-esteem and self worth with body size and shape and body weight. As distinct from its sister syndrome, Anorexia Nervosa, bulmia is associated with more affective disorder, and other personality disorders. Biological and psychological explanations of both syndromes are essentially the same and suffer from the same limitations, in that it is not really clear whether the various problems found are the cause, or the result of the syndrome. The very nature of bulimia and the fact that the bulimic patient does obtain significant satisfaction from the behaviour makes treatment extremely difficult and demanding on the professional and warrants a separate discussion.
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