anorexia nervosa and bulimia nervosa

Many people are now familiar with the disorder of anorexia nervosa, which is diagnosed by the criteria of self-induced weight loss (which may be so severe as to result in amenorrhoea in female patients) coupled with a morbid fear of becoming fat and a relentless pursuit of thinness. Other distinguishing features of the condition include a denial of the subjective feelings of hunger, a distortion of body image, and a desire to increase energy expenditure by elevated physical activity. It is potentially a fatal disorder, with mortality rates ranging from 5 to 15 per cent, mainly from suicide.

Anorexia nervosa most commonly occurs in middle-class females, although it has also been reported in males. The disorder appears generally during adolescence, though it has been known to begin prior to this period, or even during adulthood. In Britain, the incidence in young women has been estimated to range between 1 and 4 per cent. Many believe that it is a disorder of very recent origin; however, patients with such a disorder have been described by physicians practising from the 17th century onwards.

The related disorder bulimia nervosa is far less well known, perhaps partly because of its antisocial and somewhat shocking symptoms, which may have retarded its identification. Bulimia was not differentiated from anorexia and was not described as a distinct disorder until very recently. Like anorectics, bulimics have a distorted body image, are obsessed with their body weight, and have a tremendous fear of becoming fat. However, bulimics have an overwhelming desire to eat large quantities of food at a single sitting (termed 'compulsive' or 'binge' eating); they then immediately self-induce vomiting, abuse laxatives, or use both these forms of purging before the food has had time to be digested and absorbed. The majority of bulimics induce vomiting by pushing their fingers into the throat, thus producing the gagging reflex. Use of this method frequently results in calluses over the dorsum of the hand caused by its rubbing against the upper teeth (see Russell 1979: Fig. 1). But some bulimics have developed their purging techniques to such a degree that they simply need to stoop over the toilet to vomit.

Thoughts about food and body weight are obsessional, and the behaviour related to food becomes compulsive. For example, some bulimics have as many as 20 or 30 episodes of bingeing and vomiting in a 24-hour period. The energy value of food consumed during frequent binges has been measured, and it was found that a bulimic subject may be eating food with an energy value of at least 26 megajoules (about 6,214 kilocalories) per day. Obviously, much of this energy would never be absorbed, because the partly digested food would be expelled by vomiting immediately following the binge. By contrast, women with no history of eating disorders and with comparable indices of body weight were eating food with an energy value of under 15 megajoules (approximately 2,585 kilocalories) per day.

Many bulimics have never been treated for their disorder, since many retain normal or slightly below normal weight through the use of these bizarre purging methods. Hence, unlike the painfully thin anorectic, whose illness is obvious to both her doctor and others around her, the bulimic may be ill for years without anyone discovering her secret disorder, not even her husband, parents, or friends.

The causes of these two disorders are not known; there is no convincing evidence for either inherited or biologically determining factors. Anorexia nervosa has been viewed in the psychodynamic sense as a struggle towards a self-respecting identity, as a 'defensive, biologically regressed' attitude taken in response to pressures (especially sexual ones) experienced in puberty, and as an attempt to realize society's current view of the ideal feminine figure as sylphlike. Similarly, evidence has been provided that the development of bulimia is related to the struggle to attain a perfect stereotyped female image of beauty, helplessness, and dependence.

Both anorexia nervosa and bulimia nervosa are very resistant to treatment, with a less favourable prognosis for bulimia nervosa than for anorexia nervosa. Thus physical complications, such as potassium depletion, urinary infections, and renal failure, are more frequent and dangerous, and the risk of suicide is greater for those suffering from bulimia.

Pharmacological treatment is possible, and the drugs that have been used exert their behavioural actions through the central monoamine and opiate neurotransmitter systems. Certain drugs that have been shown to be effective in the treatment of other psychiatric or neurological disorders — for example, chlorpromazine used predominantly in treating schizophrenia and which appears to have had some success in combating compulsive behaviour — have been used to treat patients with anorexia or bulimia nervosa. In addition, tricyclic antidepressants have been tried in several studies. The results of these drug trials to date have been unconvincing, however, because of the small number of subjects studied and the failure in general to use control procedures. Indeed, in the few studies where the latter procedure has been implemented, pharmacological treatment has not been shown to be effective.

It has been reported in one study that in-patient treatment for anorexia nervosa was required in 80 per cent of cases. When the patient was separated from her family, weight was usually restored but only with some difficulty, using a combination of psychotherapy, capable nursing, and, in about half of the cases, treatment with chlorpromazine. Most patients were reported to take between one and five years to stabilize their weight at a reasonable level, to lose their fear of increasing weight, and to be considered fully recovered.

Some success has been reported in treating bulimic patients using a 'cognitive–behavioural' approach. This focuses on increasing the patient's control of eating, eliminating food avoidance, and changing maladaptive attitudes. A recent approach, with some similarities to this, combines dietary and cognitive techniques. The patient is placed on a calorie-controlled diet that allows her to control her weight at an acceptable level while enabling her to eat a balanced diet, including food rich in carbohydrate, which is normally irrationally avoided. This dietary regimen is coupled with behavioural modification techniques, together with cognitive and self-control strategies. Behaviour therapy is employed to help render normal the patient's eating patterns, while the cognitive techniques enable her to concentrate on other creative, positive aspects of her life, rather than on ruminations about her body weight and feeding behaviour.

(Published 1987)

— Barbara J. Sahakian

Bibliography
• Boskind-Lodahl, M., and Sirlin, J. (1977). 'The gorging–purging syndrome'. Psychology Today, Mar.
• Bruch, H. (1978). The Golden Cage: The Enigma of Anorexia Nervosa.
• Crisp, A. H. (1977). 'Anorexia nervosa'. Proceedings of the Royal Society of Medicine, 70.
• Dally, P. (1977). 'Anorexia nervosa: do we need a scape-goat?' Proceedings of the Royal Society of Medicine, 70.
• Lask, B., and Bryant-Waugh, R. (2000). Anorexia Nervosa and Related Eating Disorders in Childhood and Adolescence (2nd edn.).
• Minuchin, S., Rosman, B., and Baker, L. (1978), Psychosomatic Families: Anorexia Nervosa in Context.
• Russell, G. F. M. (1979). 'Bulimia nervosa: an ominous variant of anorexia nervosa'. Psychological Medicine, 9.
• — —  (1983). 'Anorexia nervosa'. In Weatherall, D. J., Ledingham, J. G. G., and Warrell, D. A. (eds.), Oxford Textbook of Medicine.

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