Bulimia Nervosa
Bulimia is a complex condition that has been recognised only relatively recently and brought to public attention. It remains poorly understood but the incidence of bulimia is thought to be about 1% in the western female population. It is considered to be a condition of western societies, principally seen among Caucasians. Bulimia is much more common in females, usually affecting adolescents and young adults.
The underlying causes of bulimia are still unknown. It is believed that about 50% of patients with bulimia have suffered from anorexia in the past. The majority of people with eating disorders are still technically classified as “EDNOS” (i.e. eating disorder not otherwise specified). In reality this classification acknowledges the overlap between the symptoms of eating disorders and complicates the treatment. Many of the factors that are thought to contribute to the aetiology of anorexia are likely to apply also to the aetiology of bulimia.
The factors that contribute to the development of bulimia are varied and in reality highly individual. They potentially include individual or family factors and wider social factors.
Individual / family factors include:
- female adolescence
- low self-esteem
- personal or family history of depression
- personal or family history of obesity
- high personal expectations
- family history of eating disorders
- disturbed family interactions
Social factors might include:
- pressure to slim
- pressure to conform and to achieve
Precipitating factors are general stresses, especially those that threaten self-esteem.
Clinical Features
Bulimia can present with a range of clinical features. These include concerns about shape and weight, an intractable urge to overeat with binges invariably occurring in isolation. They are associated with a sense of loss of control and invariably with guilt and feelings of shame or self-loathing. Binge eating often first induces a feeling of relief which is followed by one of disgust. Patients may then induce vomiting.
Repeated vomiting in itself causes many physical health problems including: potassium depletion potentially causing cardiac arrhythmias, renal impairment, muscular paralysis or spasms, erosion of dental enamel from vomiting stomach acid, calluses over knuckles from scraping against incisors when inducing vomiting and swollen salivary glands - particularly, the parotid glands on the cheeks.
In “pure” bulimia, rather than mixed eating disorders or “EDNOS”, weight usually remains within the normal range.
Diagnostic Criteria
Diagnostic criteria includes frequent bulimic episodes i.e. episodes of gross overeating which are associated with a subjective sense of loss of control together with a range of other compensatory behaviour, such as: dieting, self-induced vomiting, purgative abuse (laxatives), diuretic use and vigorous exercising.
There are inevitably extreme concerns about shape and weight - the same "core psychopathology" as in anorexia. The relationship between this disorder and anorexia remains somewhat controversial.
Investigations
The principle medical investigations for monitoring complications of bulimia are related to electrolyte disturbances - notably hypokalaemia (low blood Potassium). Serum amylase is sometimes raised although the cause is uncertain. ECGs are indicated if electrolytes disturbances are identified and blood tests need to be repeated at regular intervals if bulimia is severe. Patients with low body weights and bulimia are at highest risk of sudden death making monitoring and treatment all the more pressing.
Treatment
A combination of antidepressants and psychological treatment is considered the best option. Generally, medication involves a particular type of antidepressant – the selective serotonin reuptake inhibitors, such as Fluoxetine (Prozac) which are licensed for the treatment of bulimia, often at relatively high doses of around 60mg per day.
Psychotherapy is also a mainstay of treatment and a particular form of psychotherapy, Cognitive Behavioural Therapy, has a good evidence base. During the course of psychotherapy, patients aim to understand the links between their feelings and thoughts and behaviour and try to develop alternative strategies for managing their symptoms. Often other models, such as viewing bulimia as addictive behaviour or addressing issues such as self esteem, might offer a more understandable explanation. This may be particularly difficult as sufferers of bulimia can present a self-assured façade or even deny the severity or existence or their symptoms for a variety of complex reasons.