Introduction
Anorexia nervosa is characterised by a low body mass index (BMI), fear of gaining weight, denial of current low weight and its impact on health, and amenorrhoea. Estimated prevalence is highest in teenage girls, and up to 0.7% of this age group may be affected. While most people with anorexia nervosa recover completely or partially, about 5% die of the condition, and 20% develop a chronic eating disorder. Young women with anorexia nervosa are at increased risk of bone fractures later in life.
Methods and outcomes
We conducted a systematic review which aimed to answer the following clinical questions: What are the effects of treatments for anorexia nervosa? What are the effects of interventions to prevent or treat complications of anorexia nervosa? We searched: Medline, Embase, The Cochrane Library, and other important databases up to August 2007 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
Results
We found 40 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
Conclusions
In this systematic review we present information relating to the effectiveness and safety of the following interventions: anxiolytic drugs, cyproheptadine, inpatient/outpatient treatment setting, oestrogen treatment, psychotherapy, refeeding, selective serotonin reuptake inhibitors (SSRIs), and tricyclic antidepressants.
Key Points
Anorexia nervosa is characterised by a low BMI, fear of gaining weight, denial of current low weight and its impact on health, and amenorrhoea.
Estimated prevalence is highest in teenage girls, and may affect up to 0.7% of this group.Anorexia nervosa is related to family, sociocultural, genetic, and other biological factors. Psychiatric and personality disorders such as depression, anxiety disorders, obsessive compulsive disorder, and perfectionism, are commonly found in people who have anorexia nervosa.Most people with anorexia nervosa recover completely or partially, but about 5% die from the condition and 20% develop a chronic eating disorder.Young women with anorexia nervosa are at increased risk of fractures later in life.
There is no strong research evidence that any treatments work well for anorexia nervosa. However, there is a gradual accumulation of evidence which suggests that early intervention is effective. Working with the family may also interrupt the development of a persistent form of the illness.
Evidence on the benefits of psychotherapy is unclear.
Refeeding is a necessary and effective component of treatment, but is not sufficient alone.
Very limited evidence from a quasi-experimental study suggests that a lenient approach to refeeding is as effective and more acceptable compared with a more strict approach.Refeeding may be as effective in an outpatient setting as during hospital admission.Nasogastric feeding is rarely required and can lead to problems due to hypophosphataemia.Nutritional supplements, including zinc, have only limited evidence for their effectiveness, and additional evaluation of these measures are warranted.
Limited evidence from small RCTs has not shown significant weight gain from SSRIs or tricyclic antidepressants, some of which may cause serious adverse effects.
Tricyclic antidepressants may cause drowsiness, dry mouth, blurred vision, and a prolonged QT interval in people who have anorexia nervosa.
SSRIs have not been shown to be beneficial, but the evidence remains very limited; in the four RCTs we found, conclusions were limited due to small trial size and high withdrawal rates.
Anxiolytic drugs (mainly older generation antipsychotic drugs) may prolong the QT interval, increasing the risk of ventricular tachycardia, torsades de pointes, and sudden death.
Atypical antipsychotics have been evaluated for their potential role in reducing agitation and anxiety related to refeeding, as well as for potentially increasing appetite. Weak observational evidence has suggested that they may decrease obsessiveness and agitation. However, we found no RCTs of sufficient quality on the effects of atypical antipsychotics, and further evidence from large, well-conducted RCTs is necessary to draw reliable conclusions. Some atypical antipsychotics do not appear to be associated with the same cardiac risks as older-generation antipsychotic drugs. However, further research needs to be done.
We found insufficient evidence assessing cyproheptadine for treating anorexia nervosa.
Oestrogen treatment has been hypothesized to reduce the negative effects on bone mineral density associated with anorexia nervosa. However, three small RCTs have failed to demonstrate significant changes in bone mineral density after treatment with oestrogen.