CLINICAL REVIEW: Eating disorders

Headnote

The essentials

* Children as young as eight may develop eating disorders.

* Some bulimic patients wait five or six years before they ask for help.

* Anorexia has the highestpremature mortality rate for psychiatric patients.

* GPs have a vital role in detection, assessment and early intervention.

* In anorexia nervosa, 5 per cent of patients will die despite treatment.

1. Epidemiology and aetiology

Eating disorders are serious and complex illnesses, and among the most common psychiatric disorders in young women. Many people do not ask for help, so the GP has a vital role in early detection and assessment. The treatment is multidisciplinary and often long term.

Prevalence

The lifetime prevalence of anorexia nervosa in young women ranges from 0.5 to 3.7 per cent, and for bulimia nervosa from 1.1 to 4.2 per cent. The incidence of anorexia nervosa is stable, but the incidence of bulimia nervosa is rising. A GP should expect one person with anorexia nervosa and about 12 patients with bulimia nervosa on their books.

Multidimensional aetiology

The aetiology of eating disorders is multidimensional, and various risk factors have been identified. These include genetic factors, a cultural value of thinness, childhood obesity, the early onset of puberty and adverse life experiences. Personality traits, bullying,low self-esteem, dieting and exercise and family dysfunction may also predispose to an eating disorder. Most sufferers are female, with only 10 per cent being male.

The onset of anorexia usually occurs in the early teens, and in late teens for bulimia, but children as young as eight may develop these disorders. Anorexia nervosa is a global phenomenon and has no social class bias. Bulimia nervosa is more culture-bound. Certain groups of people, such as ballet dancers, models and gymnasts, have a high incidence of eating disorders.

Genetic factors

Genetic factors play an important role and contribute to half the risk, but we do not know what is inherited - it could be a vulnerable personality type.The genetic and environmental risk factors interact, and the physical and psychosexual changes of adolescence act as a powerful precipitant. Dissatisfaction with shape and size leads to dieting behaviour, which could act as a precipitant for those already at risk.

Diagnosis

When considering diagnosis, the best way to think...