Consistent with the current way of classifying eating disorders, the research on their treatment has focused on the particular disorders in isolation. Wilson and colleagues8
have provided a narrative review of the studies of the treatment of the 2 specific eating disorders as well as eating disorder NOS, and an authoritative meta-analysis has been conducted by the UK National Institute for Health and Clinical Excellence (NICE).1
This systematic review is particularly rigorous and, as with all NICE reviews, it forms the basis for evidence-based guidelines for clinical management.
The conclusion from the NICE review, and 2 other recent systematic reviews,9,10
is that cognitive behavioral therapy (CBT-BN) is the clear leading treatment for bulimia nervosa in adults. However, this is not to imply that CBT-BN is a panacea, as the original version of the treatment resulted in only fewer than half of the patients who completed treatment making a full and lasting recovery.8
The new “enhanced” version of the treatment (CBT-E) appears to be more effective.2
Interpersonal psychotherapy (IPT) is a potential evidence-based alternative to CBT-BN in patients with bulimia nervosa and it involves a similar amount of therapeutic contact, but there have been fewer studies of it.11,12
IPT takes 8 to 12 months longer than CBT-BN to achieve a comparable effect. Antidepressant medication (eg, fluoxetine at a dose of 60 mg daily) has also been found to have a beneficial effect on binge eating in bulimia nervosa but not as great as that obtained with CBT-BN and the long-term effects remain largely untested.13
Combining CBT-BN with antidepressant medication does not appear to offer any clear advantage over CBT-BN alone.13
The treatment of adolescents with bulimia nervosa has received relatively little research attention to date.
There has been much less research on the treatment of anorexia nervosa. Most of the studies suffer from small sample sizes and some from high rates of attrition. As a result, there is little evidence to support any psychological treatment, at least in adults. In adolescents the research has focused mainly on family therapy, with the result that the status of CBT in younger patients is unclear.
Preliminary findings have been reported from a 3-site study of the use of the enhanced form of CBT (CBT-E) to treat outpatients with anorexia nervosa.14
This is the largest study of the treatment of anorexia nervosa to date. In brief, it appears that the treatment can be used to treat about 60% of outpatients with the disorder (BMI 15.0 to 17.5) and that in these patients about 60% have a good outcome. Interestingly and importantly the relapse rate appears low.
There is a growing body of research on the treatment of binge-eating disorder. This research has been the subject of a recent narrative review15
and several systematic reviews.1,16,17
The strongest support is for a form of CBT similar to that used to treat BN (CBT-BED). This treatment has been found to have a sustained and marked effect on binge eating, but it has little effect on body weight, which is typically raised in these patients. Arguably the leading first-line treatment is a form of guided cognitive behavioral self-help as it is relatively simple to administer and reasonably effective.18
Until recently, there had been almost no research on the treatment of forms of eating disorder NOS other than binge-eating disorder despite their severity and prevalence.7
However, recently the first randomized controlled trial of the enhanced form of CBT found that CBT-E was as effective for patients with eating disorder NOS (who were not significantly underweight; BMI >17.5) as it was for patients with bulimia nervosa with two-thirds of those who completed treatment having a good outcome.2
In summary, CBT is the treatment of choice for bulimia nervosa and for binge-eating disorder with the best results being obtained with the new “enhanced” form of the treatment. Recent research provides support for the use of this treatment with patients with eating disorder NOS and those with anorexia nervosa.
The remainder of this article provides a description of this transdiagnostic form of CBT.