The Effects of Pharmacological Treatment on Anorexia Nervosa

Belinda Buchanan

The Characteristics of Anorexia Nervosa

Individuals with anorexia nervosa are so successful at losing weight that they put their lives in a great deal of danger. Although dramatic weight loss is the most noticeable feature of the disease, anorexics also have an intense fear of obesity and pursue thinness with unparallelled ambition (Bruch, 1986). Anorexia is most common among females, with only about five percent of those suffering from the disease being male. It is also most likely to develop in young females as a result of societal pressures on women to remain slim. The DSM-4 criteria for anorexia nervosa contains the following factors : maintenance of a body weight which is less than 85% of that expected for normal weighing individuals, intense fear of becoming overweight, disturbance or distortion of how one views their own body weight or shape, and the absence of at least three consecutive menstrual cycles. The Diagnostic and Statistical Manual specifies two types of anorexia : restricting type and binge-eating-purging type. The restricting type refers to those who do not regularly binge eat or purge, while the binge-eating-purging type refers to those who regularly engage in binge eating and purging behavior during an episode of anorexia. Anorexia nervosa is very difficult to treat due to the misconceptions in the minds of the afflicted individuals. While psychosocial treatments have been proven to be helpful, very little evidence exists to suggest that pharmacological treatment could be effective.

The Effects of Antipsychotic Medication on the Treatment of Anorexia

The first attempts to use medicine in the treatment of anorexia nervosa were performed by Dally and Sargant (1966) and used the antipsychotic drug, chlorpromazine (http://pharminfo.com/pubs/msb/seroton.html). Although a significant number of patients treated with this drug gained weight faster and were discharged sooner than those who received no medication, the chlorpromazine treated patients were no better off than those who were not treated with medicine on the follow-up, suggesting no beneficial effects of this medication. Also, the side effects of chlorpromazine were horrific. A number of the patients developed very serious seizures, and almost half of them developed bulimia nervosa.

Vandereycken and Pierloot's (1982) study using pimozide was based on the finding that increased central dopaminergic activity might be a cause of anorexia. Although no change occurred in the patients' behavior or attitude, a very small, but significant, increase in the mean daily weight gain did occur. In 1984, Vandereycken followed up with a study on the antipsychotic drug, sulpiride. However, no statistically significant effects of sulpiride occurred on either the mean daily weight change or the behavioral and attitudinal characteristics of the patients.

Due to the inability to clearly determine if neuroleptics do help in the treatment of anorexia, interest in the use of this type of medication has greatly decreased. Also, the horrific side effects have led some clinicians away from neuroleptics. However, in very occasional rare cases, experienced clinicians have used antipsychotic medication to treat anorexia.

The Effects of Antidepressant Medication on the Treatment of Anorexia

Two primary reasons exist for the initial use of antidepressants in the treatment of anorexia : depression is very common among patients suffering from anorexia, and some depression patients who are treated with tricyclic antidepressants for major depressive episodes experience significant weight gain (http://www.rxmed.com/illness/anorexia nervosa.html ; http://pathfinder.com/@@aiA71AcAbKlAwRGh/thrive/health/Library/illsymp/illness25.html).

The first controlled trial of a tricyclic antidepressant in anorexia nervosa, performed by Lacey and Crisp (1980) tested the effects of clomipramine on anorexic patients. No evidence was found in this trial of an increased rate of weight gain in the patients receiving the medication. However, the dose of clomipramine administered to the patients in this study was so extremely low that the lack of a significant outcome may be due to the low dose and not the inability of the drug to work.

The first study of amitriptyline in the treatment of anorexia was conducted by Biederman et al (1985) and showed no evidence of an increase in weight gain or improvement in any symptomatic measure. In 1986, a larger study by Halmi et al suppported the previous study. Although it was suggested that amitriptyline may have reduced the number of days required to reach target weight among the patients who were able to achieve that goal, most of the results showed no significant advantage from the use of amitriptyline.

Therefore, the few studies which have been performed on the role of antidepressant medication in treatment for anorexia do not suggest a big role for tricyclic antidepressants in the treatment of this syndrome. However, all of the above studies were not addressing whether antidepressant medication alone had any effect, but whether antidepressant medication increased the effectiveness of established treatment programs.

The Effects of Cyproheptadine on the Treatment of Anorexia

The serotonin antagonist, Cyproheptadine, has also been studied as a method of treating anorexia. There are a number of reasons why this drug has been tested. First, the use of this drug in children suffering from asthma was associated with significant weight gain in the children. Also, previous studies have suggested that serotonin plays an important role in the control of eating behavior. For example, an increase of serotonin in the hypothalamus leads to a decrease in food consumption, while a decrease in serotonin is related to an increase in food intake.

The first controlled study of cyproheptadine was performed by Vigersky and Loriaux (1977) and demonstrated a weight gain in 31% of the patients. However, Goldberg et al (1979) demonstrated no significant difference in weight gain between those taking the drug and those not taking it. A follow-up of these patients did suggest that some patients with very severe forms of the disease did benefit from cyproheptadine. Halmi et al's (1986) study showed a differential drug effect between the bulimic and nonbulimic subgroups of anorexia. Cyproheptadine significantly increased treatment efficiency in nonbulimic patients, but impaired treatment efficiency in bulimic patients. These data suggest that cyproheptadine may be beneficial in the treatment of the nonbulimic subgroup of anorexic patients.

The Effects of Lithium on the Treatment of Anorexia

Due to the known association beteen lithium treatment and weight gain, Gross et al (1981) conducted a controlled trial of lithium carbonate in anorexia nervosa. This study suggested that lithium carbonate might provoke weight gain in patients with anorexia nervosa, but it has not been followed up or supported by larger and more in depth studies.

The Effects of Tetrahydrocannabinol on the Treatment of Anorexia

In 1983, Gross et al also carried out a controlled experiment of delta-9-tetrahydrocannabinal to test the idea that the appetite-stimulating effects of this prominent psychoactive component of marijuana might be beneficial to patients suffering from anorexia. Tetrahydrocannabinal did not promote weight gain in the patients, and was associated with severe dysphoric reactions in about 25% of the patients.

The Overall Effects of Pharmacological Treatment on Anorexia

Over the past fifty years, psychiatry has demonstrated advances in the development of pharmacological treatments for many major psychiatric illnesses. Although anorexia nervosa was clearly described more than one hundred years ago, it appears that anorexia is not responsive to this pharmacological intervention. Until further research can provide a pharmacological treatment for anorexia, clinicians must remain content dealing with this disease, which is so difficult to treat, through measures such as psychosocial therapy.

Bibliography

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Bruch, H. (1986). Anorexia nervosa: The therapeutic task. Handbook of eating disorders: Physiology, psychology, and treatment of obesity, anorexia, and bulimia. New York: Basic Books.

Dally, P., & Sargant, W. (1960). A new treatment of anorexia nervosa. British Medical Journal, 1,1770-1773.

Goldberg, S. C., Halmi, K. A., & Eckert, E. D. (1979). Cyproheptadine in anorexia nervosa. British Journal of Psychiatry, 134, 67-70.

Gross, H. A., Ebert, M. H., & Faden, V. B. (1981). A double blind controlled trial of lithium carbonate in primary anorexia nervosa. Journal of Clinical Psychopharmacology, 1,376-381.

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Vandereycken, W., & Pierloot R. (1982). Pimozide combined with behavior therapy in the short term treatment of anorexia nervosa. Acto Psychiatry Scandinavia, 66, 445-450.

Vigersky, R. A., & Loriaux, D. L. (1977). The effect of cyproheptadine in anorexia nervosa: a double blind trial, in Anorexia Nervosa. New York, Raven.