A case series evaluation of guided self-help for bulimia nervosa using a cognitive manual

Conceptualising Binge Eating: A Review of the Theoretical and Empirical Literature

Binge eating is a distressing symptom common to bulimia nervosa (BN), anorexia nervosa binge/purge subtype (AN-BP) and binge-eating disorder (BED). Over the last 40 years, many attempts have been made to conceptualise this symptom in terms of its antecedents, function, triggers, consequences, and maintaining factors. Cognitive theories of binge eating have evolved as new evidence has emerged. This literature review summarises the main and most influential cognitive models of binge eating across different eating disorder presentations. Many theories have examined binge eating in the context of restriction or compensatory behaviours, as is often observed in cases of BN. Few theories have examined binge eating as it occurs in BED specifically. The long-term efficacy of cognitive behavioural therapy (CBT) treatment based on these models leaves much to be desired, and indicates that there may be maintaining factors of binge eating not addressed in the typical CBT treatment for eating disorders. More recent cognitive models of binge eating propose possible maintaining beliefs, but further study is required to validate these models. Suggestions for future research are presented.

A systematic review of the existing models of disordered eating: Do they inform the development of effective interventions?

Despite significant advances in the development of prevention and treatment interventions for eating disorders and disordered eating over the last decade, there still remains a pressing need to develop more effective interventions. In line with the 2008 Medical Research Council (MRC) evaluation framework from the United Kingdom for the development and evaluation of complex interventions to improve health, the development of sound theory is a necessary precursor to the development of effective interventions. The aim of the current review was to identify the existing models for disordered eating and to identify those models which have helped inform the development of interventions for disordered eating. In addition, we examine the variables that most commonly appear across these models, in terms of future implications for the development of interventions for disordered eating. While an extensive range of theoretical models for the development of disordered eating were identified (N=54), only ten (18.5%) had progressed beyond mere description and to the development of interventions that have been evaluated. It is recommended that future work examines whether interventions in eating disorders increase in efficacy when developed in line with theoretical considerations, that initiation of new models gives way to further development of existing models, and that there be greater utilisation of intervention studies to inform the development of theory.

Participation and outcome in manualized self-help for bulimia nervosa and binge eating disorder - a systematic review and metaregression analysis

There is a growing body of research on manualized self-help interventions for bulimia nervosa (BN) and binge eating disorder (BED). Study and treatment dropout and adherence represent particular challenges in these studies. However, systematic investigations of the relationship between study, intervention and patient characteristics, participation, and intervention outcomes are lacking. We conducted a systematic literature review using electronic databases and hand searches of relevant journals. In metaregression analyses, we analyzed study dropout as well as more specific measures of treatment participation in manualized self-help interventions, their association with intervention characteristics (e.g. duration, guidance, intervention type [bibliotherapy, CD-ROM or Internet based intervention]) and their association with treatment outcomes. Seventy-three publications reporting on 50 different trials of manualized self-help interventions for binge eating and bulimia nervosa published through July 9th 2012 were identified. Across studies, dropout rates ranged from 1% to 88%. Study dropout rates were highest in CD-ROM interventions and lowest in Internet-based interventions. They were higher in samples of BN patients, samples of patients with higher degrees of dietary restraint at baseline, lower age, and lower body mass index. Between 6% and 88% of patients completed the intervention to which they had been assigned. None of the patient, study and intervention characteristics predicted intervention completion rates. Intervention outcomes were moderated by the provision of personal guidance by a health professional, the number of guidance sessions as well as participants' age, BMI, and eating disorder related attitudes (Restraint, Eating, Weight and Shape Concerns) at baseline (after adjusting for study dropout and intervention completion rates). Guidance particularly improved adherence and outcomes in samples of patients with bulimia nervosa; specialist guidance led to higher intervention completion rates and larger intervention effects on some outcomes than non-specialist guidance. Self-help interventions have a place in the treatment of BN and BED, especially if the features of their delivery and indications are considered carefully. To better determine who benefits most from what kind and "dosage" of self-help interventions, we recommend the use of consistent terminology as well as uniform standards for reporting adherence and participation in future self-help trials.

A cross-sectional analysis of the cognitive model of bulimia nervosa

OBJECTIVE

The present study aimed to directly test Cooper et al.'s cognitive model of the maintenance of bulimia nervosa.

METHOD

The major predictions of the model were tested cross-sectionally using multiple regression analyses and structural equation modeling in a mixed sample comprising nonclinical female university students (n = 298) and clinical eating disorder patients (n = 44).

RESULTS

Consistent with model, negative self-beliefs was associated with negative emotion, negative emotion with positive and negative beliefs about eating, beliefs about eating with eating behavior, and binge eating with negative self-beliefs. However, contrary to hypotheses, results did not consistently support a direct link between compensatory behavior and negative self-beliefs. Furthermore, the role of permissive thoughts was found to be questionable. Of note, results suggested that components of the model may operate to maintain bulimic pathology in a slightly different way for purging and nonpurging behaviors.

DISCUSSION

While the results of this research provide some preliminary evidence for the validity of the cognitive model as an explanation of the persistence of bulimic symptoms, further work is required to develop the model.

How many therapists? Practical guidance on investigating therapist effects in randomized controlled trials for eating disorders

OBJECTIVE

An important question in implementation/dissemination research is whether the efficacy of a given treatment varies in part based on the therapist delivering the treatment. This study sought to provide practical guidance to researchers in the field of eating disorders for building measurement of therapist effects into the design of a typical, relatively small randomized controlled trial (RCT).

METHOD

Using assumptions based on past trials of eating disorder treatments, Monte Carlo simulations were used to examine 12 different scenarios based on crossing the number of therapists (between two and five) and the estimated therapist effect size (small, medium, and large). Patient sample size and study design were held constant.

RESULTS

There was reasonable power (≥70%) to detect the therapist effect with three or four therapists and a large effect size.

DISCUSSION

Several practical implications for testing therapist effects in RCT are discussed.

A critical evaluation of the efficacy of self-help interventions for the treatment of bulimia nervosa and binge-eating disorder

OBJECTIVE

Cognitive behavioral therapy (CBT) is efficacious for the treatment of bulimia nervosa (BN) and binge-eating disorder (BED). As a number of factors limit the availability of CBT, self-help manuals have been developed to make the treatment more widely available.

METHOD

Published studies evaluating the efficacy of self-help programs in the treatment of BN and BED were reviewed.

RESULTS

Controlled studies of self-help programs for BN and BED have often employed a waiting list control group, and indicate that self-help provides more benefit than remaining on a waiting list. However, fewer studies have utilized a more active control group, and these studies have not been as positive.

CONCLUSION

In general, open and wait-list trials indicate that self-help is helpful in treating BN and BED, but there is little evidence for the specific efficacy of self-help in comparison to other treatments. Additional studies of self-help are needed to determine the specific utility of self-help interventions for BN and BED.

Treatment of bulimia nervosa: where are we and where are we going?

OBJECTIVE

The purpose of this article is to review the extant treatment literature on bulimia nervosa and to offer suggestions for future research directions.

METHOD

The available treatment studies regarding both pharmacotherapy and psychotherapy are reviewed.

RESULTS

Both pharmacotherapy and psychotherapy appear to play a role in the treatment of bulimia nervosa; however, available data suggest that cognitive behavioral therapy remains the treatment of choice.

CONCLUSION

Additional work is clearly indicated regarding assisted and unassisted self-help. An enhanced form of CBT and the integrative cognitive-affective therapy both deserve further study. New approaches need to be piloted. More research is needed on treatment modeling.

Self-help and guided self-help for eating disorders

BACKGROUND

Anorexia nervosa (AN), bulimia nervosa (BN), binge eating disorder (BED) and eating disorder not otherwise specified (EDNOS) are common and disabling disorders. Many patients experience difficulties accessing specialist psychological treatments. Pure self-help (PSH: self-help material only) or guided self-help (GSH: self-help material with therapist guidance), may bridge this gap.

MAIN OBJECTIVE

Evaluate evidence from randomised controlled trials (RCTs) / controlled clinical trials (CCTs) for the efficacy of PSH/GSH with respect to eating disorder symptoms, compared with waiting list or placebo/attention control, other psychological or pharmacological treatments (or combinations/augmentations) in people with eating disorders.

SECONDARY OBJECTIVE

Evaluate evidence for the efficacy of PSH/GSH regarding comorbid symptomatology and costs.

SEARCH STRATEGY

CCDANCTR-Studies and CCDANCTR-References were searched in November 2005, other electronic databases were searched, relevant journals and grey literature were checked, and personal approaches were made to authors.

SELECTION CRITERIA

Published/unpublished RCTs/CCTs evaluating PSH/GSH for any eating disorder.

DATA COLLECTION AND ANALYSIS

Data was extracted using a customized spreadsheet. Relative Risks (RR) were calculated from dichotomous data and weighted/standardized mean differences (WMD/SMD) from continuous data, using a random effects model.

MAIN RESULTS

Twelve RCTs and three CCTs were identified, all focusing on BN, BED, EDNOS or combinations of these, in adults, using manual-based PSH/GSH across various settings. Primary comparisons:At end of treatment, PSH/GSH did not significantly differ from waiting list in abstinence from bingeing (RR 0.72, 95% CI 0.47 to 1.09), or purging (RR 0.86, 95% CI 0.68 to 1.08), although these treatments produced greater improvement on other eating disorder symptoms, psychiatric symptomatology and interpersonal functioning but not depression. Compared to other formal psychological therapies, PSH/GSH did not differ significantly at end of treatment or follow-up in improvement on bingeing and purging (RR 0.99, 95% CI 0.75 to 1.31), other eating disorder symptoms, level of interpersonal functioning or depression. There were no significant differences in treatment dropout. Secondary comparisons:One small study in BED found that cognitive-behavioural GSH compared to a non-specific control treatment produced significantly greater improvements in abstinence from bingeing and other eating disorder symptoms. Studies comparing PSH with GSH found no significant differences between treatment groups at end of treatment or follow-up. Comparison between different types of PSH/GSH found significant differences on eating disorder symptoms but not on bingeing/purging abstinence rates.

AUTHORS' CONCLUSIONS

PSH/GSH may have some utility as a first step in treatment and may have potential as an alternative to formal therapist-delivered psychological therapy. Future research should focus on producing large well-conducted studies of self-help treatments in eating disorders including health economic evaluations, different types and modes of delivering self-help (e.g. computerised versus manual-based) and different populations and settings.