Complex CBT Effective in Treatment of Severe Eating Disorders

Majority of Patients Derive Benefit From Standard CBT

Pauline Anderson

December 23, 2008

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December 23, 2008 — A complex form of enhanced cognitive behavioral therapy (CBT-E) that targets perfectionism and low self-esteem as well as extreme dieting, binge eating, or purging appears to be a valid treatment option for patients with particularly severe eating disorders.

A study by investigators at Oxford University, in the United Kingdom, found that this complex form of CBT-E is effective for some eating-disorder patients, although it also found that most patients derive more benefit from the standard form of CBT-E.

"Now, for the first time, we have a single treatment that can be effective at treating the majority of cases [of eating disorders] without the need for patients to be admitted to the hospital," principal investigator Christopher G. Fairburn, MD, said in a statement.

These study results add important information to the current knowledge surrounding eating-disorder treatments, said Susan Ringwood, CEO of BEAT, the United Kingdom's only national charity supporting people affected by an eating disorder.

"We encourage people seeking treatment to make sure that any therapy they are offered has a sound evidence base, and this study adds to that evidence base," she told Medscape Psychiatry. "It will give hope and encouragement to people affected by eating disorders and their families to know that treatment can work and that recovery is possible."

The study is published online December 15 in the American Journal of Psychiatry.

Anorexia Not Included

The study included patients with bulimia nervosa or an eating disorder not otherwise specified, which includes binge-eating disorder. The latter is the most common eating disorder, followed by bulimia and then anorexia nervosa, which was not included in the current study.

Among other things, the study compared patients receiving 1 of 2 forms of CBT-E — CBT-Ef, which focuses exclusively on eating-disorder psychopathology, and CBT-Eb, a broader, more complex form that also addresses problems such as mood intolerance, perfectionism, low self-esteem, and interpersonal difficulties.

Patients in the study had to have a body-mass index (BMI) higher than 17.5 and be older than 18 years. A total of 154 patients were recruited between March 2002 and July 2005 — 93 from Oxford and 61 from Leicester.

Study subjects were randomized to 1 of 4 groups:

  • Immediate CBT-Ef (53).

  • Immediate CBT-Eb (50).

  • An 8-week waiting-list control group whose members eventually received CBT-Ef.

  • An 8-week waiting-list control group whose members eventually received CBT-Eb.

The groups were balanced by sex, eating-disorder diagnosis, BMI, and need to remain on psychotropic drugs.

Therapies Identical for 4 Weeks

Both forms of CBT-E comprised a 90-minute preparatory session followed by weekly 50-minute sessions and then a review session. The therapies were identical for the first 4 weeks, both concentrating on the eating disorder itself — for example, dealing with excessive concern with shape and weight, extreme dieting, binge eating, and purging.

For the rest of the study, the CBT-Ef continued to focus on these features while the CBT-Eb began to also address perfectionism, low self-esteem, and the other complex features of eating disorders.

Of the original 154, 5 did not attend their initial assessment. Of the 149 subjects remaining, 92 (61.7%) had a diagnosis of an eating disorder not otherwise specified (7 had binge-eating disorder) and 57 (38.3%) had a diagnosis of bulimia.

Patients were assessed before treatment, after 8 weeks of treatment, and at the end of treatment. Those in the control group were assessed at the end of the waiting-list period preceding treatment. After treatment, patients were reassessed 20, 40, and 60 weeks later.

Trained therapists assessed patients using the 16th edition of the Eating Disorder Examination Interview (EDE) and its self-report version (EDE-Q). Treatment outcomes included changes in severity of eating-disorder features and having a global EDE score less than 1 standard deviation (SD) above the community mean (1.74).

Of the 149 patients who started the study, 33 (22.1%) did not complete treatment or were withdrawn because of lack of response.

Substantial Change

The study authors found that patients in the waiting-list group experienced little change in symptoms. However, they noted substantial and very similar changes in those in the 2 CBT-E groups.

At the end of 20 weeks, more than half of the overall sample had a level of eating-disorder features less than 1 SD above the community mean of 1.74 — 52.7% of those with bulimia and 53.3% of those with an eating disorder not specified.

At the 60-week follow-up, these percentages were 61.4% for those with bulimia and 45.7% for those with an eating disorder not specified. As well, the mean changes in global EDE at the 60-week follow-up were similar in the CBT-Ef and CBT-Eb groups: 1.36 (SD = 1.42) and 1.33 (SD = 1.30), respectively.

At the end of treatment, 38.5% of patients with bulimia reported no episodes of binge eating or purging over the previous 28 days. At 60-week follow-up, the proportion was 45.6%.

Compliance with follow-up was high, with 95.1% of the assessments being successfully completed.

Focused Form Should Be Default

The only notable difference between the 2 forms of CBT-E was that the broader version appeared to be more effective than the focused form in patients with substantial additional psychopathology, whereas the opposite seemed to be the case for the remaining patients. The authors, however, stress the need to verify this finding.

"In the meantime, it would seem reasonable to use the present findings to guide clinical practice," they write. "Thus, the simpler focused form of the treatment, CBT-Ef, should perhaps be viewed as the default form, as it is easier to learn and implement, with the more complex form, CBT-Eb, reserved for patients with marked additional psychopathology."

Knowing that therapies have been proven effective for most eating disorders is a relief for families struggling with such issues, said Ms. Ringwood. "We know that anorexia nervosa is the rarest eating disorder, making up only 10% of all cases, so potentially this treatment (enhanced CBT) may benefit many of the remaining 90%."

The investigators are close to revealing results of research using CBT in patients with anorexia. Ms. Ringwood said she's encouraged by this news.

If CBT succeeds in improving outcomes and reduces the rate of hospitalization, then it could translate into significant healthcare savings, noted Ms. Ringwood. "We know that the sooner someone gets the specialist treatment they need, the more likely they are to recover and avoid the long-term consequences of an eating disorder."

She added that in-patient treatment is often lengthy and costly, "not only for healthcare services, but also in terms of the impact it makes in the life of the person affected and their loved ones."

However, there are currently not enough therapists in the United Kingdom qualified to offer CBT to everyone who might benefit from it, she said. "The UK government has recently committed significant extra funding for CBT training, and we look forward to this additional capacity becoming available."

Dr. Fairburn reports receiving royalties from Guilford Press.

Am J Psychiatry. Published online December 15, 2008. Abstract


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