15/12/08 Wellcome Trust researchers have developed a new form of psychotherapy that has been shown to have the potential to treat more than eight out of ten cases of eating disorders in adults, a study out reports.

This new "enhanced" form of cognitive behavioural therapy (CBT-E) builds on and improves the current leading treatment for bulimia nervosa as recommended by the National Institute of Health and Clinical Excellence (NICE). CBT-E is the first treatment to be shown to be suitable for the majority of cases of eating disorders.

According to NICE, eating disorders are a major cause of physical and psychosocial impairment in young women, affecting at least one in twenty women between the ages of 18 and 30. They also occur in young men but are less common. Three eating disorders are recognised: anorexia nervosa, which accounts for around one in ten cases in adults; bulimia nervosa, which accounts for a third of all cases; and the remainder are classed as "atypical eating disorders, which account for over half of all cases. In these atypical cases the features of anorexia nervosa and bulimia nervosa are combined in a different way.

The three eating disorders vary in their severity, but typically involve extreme and relentless dieting, self-induced vomiting or laxative misuse, binge eating, driven exercising and in some cases marked weight loss. Common associated features are depression, social withdrawal, perfectionism and low self-esteem. The disorders tend to run a chronic course and are notoriously difficult to treat. Relapse is common.

This new treatment derives from an earlier form of CBT that was designed exclusively for patients with bulimia nervosa. Both were developed by Professor Christopher Fairburn, a Wellcome Trust Principal Research Fellow at the University of Oxford. In 2004, the earlier treatment became the first psychotherapy to be recognised by NICE as the leading treatment for a clinical condition and its use was recommended across the NHS.

Now, in a study published in the American Journal of Psychiatry, Professor Fairburn and colleagues have shown that the enhanced version of the treatment is not only more potent than the earlier NICE-recommended treatment, but it can also be used to treat both bulimia nervosa and the atypical eating disorders, making it suitable for over 80 percent of cases of eating disorders.

"Eating disorders are serious mental health problems and can be very distressing for both patients and their families," says Professor Fairburn. "Now for the first time, we have a single treatment which can be effective at treating the majority of cases without the need for patients to be admitted into hospital."

154 people were recruited for the study which was based in Oxfordshire and Leicestershire. Two versions of CBT-E were compared: a simple version that focused solely on the eating disorder and a second, more complex version that simultaneously addressed commonly associated problems such as low self-esteem and extreme perfectionism. Both treatments comprised twenty 50-minute outpatient appointments over twenty weeks.

The researchers found that the majority of patients responded well and rapidly to the two forms of CBT-E and that the changes were sustained over the following year, the time at which relapse is most likely to occur. Approximately two-thirds of those who completed treatment made a complete and lasting response with many of the remainder showing substantial improvement. Patients with bulimia nervosa or an atypical eating disorder responded equally well, though a planned sub-analysis showed that patients with particularly complex clinical features responded better to the more complex treatment and vice versa.

"This new psychotherapy is an effective and relatively straightforward intervention for treating most clinical disorders seen in adults," says Professor Fairburn. "It is increasingly being used across the NHS and has the potential to improve the lives of the hundreds of thousands of people living with eating disorders."

Professor Fairburn and colleagues are also nearing the completion of a large-scale trial investigating the effectiveness of CBT-E as a treatment for anorexia nervosa, the interim result of which look very promising.

The findings have been welcomed by Susan Ringwood, Chief Executive Officer of Beat, the beating eating disorders campaign group: "This research shows that people can benefit from psychological therapy even at a very low weight. There has been so little research into eating disorders and anorexia in particular, and Professor Fairburn's work has really added to our knowledge in this challenging field."