Bulimia nervosa and related syndromes such as binge eating disorder are common in young Western women. A specific manual-based form of cognitive behaviour therapy (CBT) has been developed for the treatment of bulimia nervosa (CBT-BN). Other psychotherapies, some from a different theoretical framework, and some modifications of CBT are also used.
To evaluate the efficacy of CBT and CBT-BN and compare them with other psychotherapies in the treatment of adults with bulimia nervosa or related syndromes of recurrent binge eating.
A handsearch of The International Journal of Eating Disorders since its first issue; database searches of MEDLINE, EXTRAMED, EMBASE, PsycInfo, CURRENT CONTENTS, LILACS, SCISEARCH, CENTRAL and the The Cochrane Collaboration Depression, Anxiety & Neurosis Controlled Trials Register; citation list searching and personal approaches to authors were used. Search date June 2004.
All studies that have tested any form of psychotherapy for adults with non-purging bulimia nervosa, binge eating disorder and/or other types of eating disorders of a bulimic type (eating disorder not otherwise specified, or EDNOS) and which applied a randomised controlled and standardised outcome methodology. Studies with greater than 50% drop-out rates were not included.
Data collection and analysis
Data were analysed using the Review Manager software program. Relative risks were calculated for binary outcome data. Standardized mean differences were calculated for continuous variable outcome data. A fixed effects model was used to analyse the data.
Sensitivity analyses of a number of measures of trial quality were conducted. Subgroup done of dianostic groups and short (</= 10 weeks) versus longer therapies. Data were not reported in such a way to permit other subgroup analyses, but the effects of treatment on depressive symptoms, psychosocial and/or interpersonal functioning, general psychiatric symptoms and weight were examined where possible. Funnel plots were drawn to investigate the presence of publication bias.
The review supported the efficacy of cognitive-behavioural psychotherapy (CBT) and particularly CBT-BN in the treatment of people with bulimia nervosa and also (but less strongly due to the small number of trials) related eating disorder syndromes. CBT has been evaluated in group as well as individual settings. Sensitivitiy analyses did not find quality of trials changed primary outcomes, but there were frequently few trials left for meta-analyses after exluding poorer trials.
Other psychotherapies were also efficacious, particularly interpersonal psychotherapy in the longer-term. Self-help approaches that used highly structured CBT treatment manuals, were promising albeit with more modest results when applied without guidance ("pure self-help") and their evaluation in bulimia nervosa merits further research. Exposure and Response Prevention did not appear to enhance the efficacy of CBT.
Psychotherapy alone is unlikely to reduce or change body weight in people with bulimia nervosa or similar eating disorders.
There is a small body of evidence for the efficacy of CBT in bulimia nervosa and similar syndromes, but the quality of trials is very variable and sample sizes are often small. More and larger trials of CBT are needed, particularly for binge eating disorder and other EDNOS syndromes. Trials evaluating other psychotherapies and less intensive psychotherapies should also be conducted.