Anorexia

Anorexia

Introduction

A psychiatric disorder in which a dramatic reduction in caloric intake consequent to excessive dieting leads to significant bodily, physiological, biochemical, emotional, psychological, and behavioral disturbances. In 1874, the eminent English physician William Gull coined the phrase “anorexia nervosa” in a series of four case studies of young women with deliberate weight loss. Around the same time, the French physician Charles Laségue postulated that the deliberate starvation was driven by a neurosis originating from a desire to avoid pain. In the latter half of the twentieth century, environmental and cultural explanations became central to etiological explanations of anorexia nervosa, in line with the Western cultural ideal of thinness. More recently, much research has centered on biological and genetic factors underpinning the illness. Despite these developments, there are still many unknowns, and a definitive etiology and treatment strategies are yet to be established.

Diagnostic criteria

The diagnostic criteria for anorexia nervosa is described in the ICD-10 (International Statistical Classification of Diseases and Related Health Problems,10th revision) and the DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, 4th edition). The core psychopathology is defined currently as a disturbance in the way that body weight or shape is experienced. There is a dread of weight gain, along with deliberate weight loss, in order to sustain the body mass index (BMI) at 17.5 kg/m2 or lower (equivalent to 15% below the normal minimum). Abnormalities are also present in the endocrine system, and there is a loss of at least three consecutive menstrual cycles for women who are not on hormonal contraception, or a loss of libido and potency in men. The DSM-IV recognizes two further subtypes: restrictive and purging. Weight loss is achieved through food restriction with or without excessive exercise in the former, whereas the same behaviors with additional self-induced vomiting and laxative and diuretic abuse occur in the latter subtype (Maisel& Borden, 2004).

There are ongoing debates regarding the diagnostic criteria for anorexia nervosa. The psychopathology relating to weight and shape concerns is strongly influenced by Western cultural values. However, anorexia nervosa also exists in non-Western countries, where it is more likely to be explained as an inability to eat caused by physical sensations or other meanings attributed to food, such as contamination or purity. In addition, there are descriptions of self-starvation that date back to the Middle Ages, mostly for religious or aesthetic reasons. There is also an ongoing discussion on the validity of amenorrhea as a diagnostic criterion because there are reports of spontaneous menstruation in women who fulfill all other criteria for anorexia nervosa.

Epidemiology

Anorexia nervosa has been diagnosed increasingly over the past century, with incidence levels reaching a plateau in the 1970s. Since then, a study among primary-care patients in the United Kingdom found that incidence rates have been stable between the period from 1994 to 2000 (4.7 per 100,000 population). This stability, despite high publicity of the thin ideal in popular culture, suggests that anorexia nervosa is less likely the result of cultural influence than intuitively ...