Subtyping bulimic women along dietary restraint and negative affect dimensions

Elevated cognitive dietary restraint mediates the relationship between greater impulsivity and more frequent binge eating in individuals with binge-spectrum eating disorders

PURPOSE

The current study aimed to examine the relationships between impulsivity, dietary restraint, and binge eating frequency in individuals with binge-spectrum eating disorders.

METHODS

Secondary data analysis was conducted on baseline data from three ongoing or recently completed clinical trials. 148 participants diagnosed with a DSM-5 eating disorder characterized by binge eating were administered a clinical interview to assess dietary restraint and binge eating frequency and completed a self-report measure of trait impulsivity.

RESULTS

Mediation analyses found that increased dietary restraint mediated the relationship between higher impulsivity, particularly greater positive urgency and sensation-seeking, and more frequent binge eating episodes.

CONCLUSION

While more research using momentary assessment methods is necessary to confirm our findings, results from the current study call attention to the potential role of dietary restraint in the impulsivity-binge eating relationship for individuals with binge-spectrum eating disorders.

LEVEL OF EVIDENCE

Level V descriptive study.

An examination of the interpersonal model of binge eating over the course of treatment

The current study examined the interpersonal model of binge eating, which posits that interpersonal problems lead to negative affect, which results in binge eating, over the course of two psychotherapy treatments (interpersonal psychotherapy and cognitive behavioural therapy) in 162 adults with binge-eating disorder. A series of longitudinal simple mediation analyses preliminarily showed that treatment addresses the mechanisms of the interpersonal model of binge eating as theoretically proposed in predicting reductions in binge eating, the primary dependent variable, and the secondary dependent variables including global eating disorder psychopathology, shape concern, and weight concern, but not reductions in restraint or eating concern. Moderated mediation analyses did not fully support treatment differences, as changes in the mechanisms of the interpersonal model occurred in both treatments and suggest both treatments addressed negative affect and interpersonal precipitants of eating disorder symptomatology. Future research should replicate this study using variables that do not overlap in time to investigate causation of the model, and more generally, further examine theoretical treatment models and treatment mediators as this research could help improve efficacy of treatment for binge-eating disorder.

Predictors and moderators of psychological changes during the treatment of adolescent bulimia nervosa

This study examined predictors of psychological change among 80 adolescents with bulimia nervosa (BN) participating in a randomized-controlled trial comparing family-based treatment (FBT) to supportive psychotherapy (SPT). Psychological outcomes (cognitive eating disorder pathology, depression, and self-esteem) were explored at baseline, post-treatment, and 6-month follow-up. Multi-level growth models examined predictors of rate of change in psychological outcomes and moderators of treatment effects. All psychological outcomes improved through 6-month follow-up (moderate to large effect sizes) across both treatments. Overall, few significant predictors were identified. Older adolescents had faster change in self-esteem relative to younger adolescents (p = 0.03). Adolescents taking psychotropic medication at baseline had faster change in eating concerns relative to adolescents not taking medication (p = 0.02). Age (p = 0.02) and baseline purging severity (p = 0.03) moderated the relationship between treatment condition and change in eating concerns, where younger adolescents and individuals with high baseline purging had greater change when treated with FBT relative to SPT. Age and purging did not significantly moderate change in other psychological outcomes. Bulimic symptom improvement did not predict change in psychological symptoms. Generally, FBT and SPT were equally efficacious with respect to psychological improvement, although FBT may be more efficacious in younger adolescents and those with more frequent purging.

Review of smartphone applications for the treatment of eating disorders

mHealth tools may be a feasible modality for delivering evidence-based treatments and principles (EBPs), and may enhance treatment for eating disorders (EDs). However, research on the efficacy of mHealth tools for EDs and the extent to which they include EBPs is lacking. The current study sought to (i) review existing apps for EDs, (ii) determine the extent to which available treatment apps utilize EBPs, and (iii) assess the degree to which existing smartphone apps utilize recent advances in smartphone technology. Overall, existing ED intervention apps contained minimal EBPs and failed to incorporate smartphone capabilities. For smartphone apps to be a feasible and effective ED treatment modality, it may be useful for creators to begin taking utilizing the abilities that set smartphones apart from in-person treatment while incorporating EBPs. Before mHealth tools are incorporated into treatments for EDs, it is necessary that the feasibility, acceptability, and efficacy be evaluated.

Alternative methods of classifying eating disorders: models incorporating comorbid psychopathology and associated features

There is increasing recognition of the limitations of current approaches to psychiatric classification. Nowhere is this more apparent than in the eating disorders (EDs). Several alternative methods of classifying EDs have been proposed, which can be divided into two major groups: 1) those that have classified individuals on the basis of disordered eating symptoms; and, 2) those that have classified individuals on the basis of comorbid psychopathology and associated features. Several reviews have addressed symptom-based approaches to ED classification, but we are aware of no paper that has critically examined comorbidity-based systems. Thus, in this paper, we review models of classifying EDs that incorporate information about comorbid psychopathology and associated features. Early approaches are described first, followed by more recent scholarly contributions to comorbidity-based ED classification. Importantly, several areas of overlap among the classification schemes are identified that may have implications for future research. In particular, we note similarities between early models and newer studies in the salience of impulsivity, compulsivity, distress, and inhibition versus risk taking. Finally, we close with directions for future work, with an emphasis on neurobiologically-informed research to elucidate basic behavioral and neuropsychological correlates of comorbidity-based ED classes, as well as implications for treatment.

Predictors and moderators of response to cognitive behavioral therapy and medication for the treatment of binge eating disorder

OBJECTIVE

To examine predictors and moderators of response to cognitive behavioral therapy (CBT) and medication treatments for binge-eating disorder (BED).

METHOD

108 BED patients in a randomized double-blind placebo-controlled trial testing CBT and fluoxetine treatments were assessed prior, throughout, and posttreatment. Demographic factors, psychiatric and personality disorder comorbidity, eating disorder psychopathology, psychological features, and 2 subtyping methods (negative affect, overvaluation of shape/weight) were tested as predictors and moderators for the primary outcome of remission from binge eating and 4 secondary dimensional outcomes (binge-eating frequency, eating disorder psychopathology, depression, and body mass index). Mixed-effects models analyzed all available data for each outcome variable. In each model, effects for baseline value and treatment were included with tests of both prediction and moderator effects.

RESULTS

Several demographic and clinical variables significantly predicted and/or moderated outcomes. One demographic variable signaled a statistical advantage for medication only (younger participants had greater binge-eating reductions), whereas several demographic and clinical variables (lower self-esteem, negative affect, and overvaluation of shape/weight) signaled better improvements if receiving CBT. Overvaluation was the most salient predictor/moderator of outcomes. Overvaluation significantly predicted binge-eating remission (29% of participants with vs. 57% of participants without overvaluation remitted). Overvaluation was especially associated with lower remission rates if receiving medication only (10% vs. 42% for participants without overvaluation). Overvaluation moderated dimensional outcomes: Participants with overvaluation had significantly greater reductions in eating disorder psychopathology and depression levels if receiving CBT. Overvaluation predictor/moderator findings persisted after controlling for negative affect.

CONCLUSIONS

Our findings have clinical utility for prescription of CBT and medication and implications for refinement of the BED diagnosis.

The mediational significance of negative/depressive affect in the relationship of childhood maltreatment and eating disorder features in adolescent psychiatric inpatients

OBJECTIVE

Childhood maltreatment is a risk factor for eating disorder and negative/depressive affect appears to mediate this relation. However, the specific elements of eating- and body-related psychopathology that are influenced by various forms of childhood maltreatment remain unclear, and investigations among adolescents and men/boys have been limited. This study investigated the mediating role of negative affect/depression across multiple types of childhood maltreatment and eating disorder features in hospitalized adolescent boys and girls.

METHOD

Participants were 148 adolescent psychiatric inpatients who completed an assessment battery including measures of specific forms of childhood maltreatment (sexual, emotional, and physical abuse), negative/depressive affect, and eating disorder features (dietary restriction, binge eating, and body dissatisfaction).

RESULTS

Findings suggest that for girls, negative/depressive affect significantly mediates the relationships between childhood maltreatment and eating disorder psychopathology, although effects varied somewhat across types of maltreatment and eating disorder features. Generalization of mediation effects to boys was limited.

Stability and change in patterns of concerns related to eating, weight, and shape in young adult women: a latent transition analysis

Although college women are known to be at high risk for eating-related problems, relatively little is known about how various aspects of concerns related to eating, weight, and shape are patterned syndromally in this population. Moreover, the extent to which various patterns represent stable conditions or transitory states during this dynamic period of development is unclear. The present study used latent class and latent transition analysis (LCA/LTA) to derive syndromes of concerns related to eating, weight, and shape and movement across these syndromes in a sample of 1,498 women ascertained as first-time freshmen and studied over 4 years. LCA identified 5 classes characterized by (a) no obvious pathological eating-related concerns (prevalence: 28%-34%); (b) a high likelihood of limiting attempts (prevalence: 29%-34%); (c) a high likelihood of overeating and binge eating (prevalence: 14%-18%); (d) a high likelihood of limiting attempts and overeating or binge eating (prevalence: 14%-17%); and (e) pervasive bulimic like concerns (prevalence: 6%-7%). Membership in each latent class tended to be stable over time. When movement occurred, it tended to be to a less severe class. These findings indicate that there are distinct, prevalent, and relatively stable forms of eating-related concerns in college women.

Subtyping women with bulimia nervosa along dietary and negative affect dimensions: further evidence of reliability and validity

Studies have found that individuals with bulimia nervosa can be classified into dietary and dietary-negative affect subtypes and that the latter exhibit greater eating pathology, psychiatric comorbidity, and functional impairment; a more protracted clinical course; and a worse treatment response. In this report, the authors describe 2 prospective studies that found that young women with threshold (n = 48) and subthreshold (n = 83) bulimic pathology can be classified into dietary and dietary-negative affect subtypes; that two subtyping approaches produced similar results (mean kappa = .94); that the subtyping distinction showed 4-week test-retest reliability (kappa = .61); and that the dietary-negative affect subtype showed greater eating pathology, emotional distress, functional impairment, treatment seeking, and lower likelihood of recovery over 6-month and 3-year follow-ups than the dietary subtype. The dieting-negative affect subtyping distinction evidenced greater test-retest reliability and concurrent and predictive validity than did the purging-nonpurging subtyping distinction. The additional evidence for the reliability and validity of this subtyping scheme, particularly the prognostic utility, suggests it is worth additional inquiry.

Subtyping children and adolescents with loss of control eating by negative affect and dietary restraint

OBJECTIVE

Research suggests that subtyping adults with binge eating disorders by dietary restraint and negative affect predicts comorbid psychopathology, binge eating severity, and treatment outcome. Little research has explored the validity and clinical utility of subtyping youth along these dimensions.

METHOD

Children (aged 8-18 years) reporting loss of control eating (n=159) were characterized based upon measures of dietary restraint and negative affect using cluster analysis, and then compared regarding disordered eating attitudes and behaviors, and parent-reported behavior problems.

RESULTS

Robust subtypes characterized by dietary restraint (n=114; 71.7%) and dietary restraint/high negative affect (n=45; 28.3%) emerged. Compared to the former group, the dietary restraint/high negative affect subtype evidenced increased shape and weight concerns, more frequent binge eating episodes, and higher rates of parent-reported problems (all ps<0.05).

CONCLUSION

Similar to findings from the adult literature, the presence of negative affect may mark a more severe variant of loss of control eating in youth. Future research should explore the impact of dietary restraint/negative affect subtypes on psychiatric functioning, body weight, and treatment outcome.

Prognostic significance of two sub-categorization methods for the treatment of binge eating disorder: negative affect and overvaluation predict, but do not moderate, specific outcomes

Given the absence of known predictors and moderators for binge eating disorder (BED) treatment outcome and recent findings regarding meaningful sub-categorizations of BED patients, we tested the predictive validity of two subtyping methods. Seventy-five overweight patients with BED who participated in a randomized clinical trial of guided self-help treatments (cognitive-behavioral therapy (CBTgsh) and behavioral weight loss (BWLgsh)) were categorized in two ways. First, a cluster analytic approach yielded dietary-negative affect (29%) and pure dietary (71%) subtypes. Second, research conventions for categorizing patients based upon shape or weight self-evaluation yielded clinical overvaluation (51%) and subclinical overvaluation (49%) subtypes. At the end of treatment, participants subtyped as dietary-negative affect reported more frequent binge episodes compared to the pure dietary subtype, and those with clinical overvaluation reported greater eating disorder psychopathology compared to the subclinical overvaluation group. Neither method predicted binge remission, depressive symptoms, or weight loss. Neither sub-categorization moderated the effects of guided self-help CBT and BWL treatments on any BED outcomes, suggesting that these two specific treatments perform comparably across BED subtypes. In conclusion, dietary-negative affect subtyping and overvaluation subtyping each predicted, but did not moderate, specific and important dimensions of BED treatment outcome.

Subtyping adolescents with bulimia nervosa

Cluster analyses of eating disorder patients have yielded a "dietary-depressive" subtype, typified by greater negative affect, and a "dietary" subtype, typified by dietary restraint. This study aimed to replicate these findings in an adolescent sample with bulimia nervosa (BN) from a randomized controlled trial and to examine the validity and reliability of this methodology. In the sample of BN adolescents (N=80), cluster analysis revealed a "dietary-depressive" subtype (37.5%) and a "dietary" subtype (62.5%) using the Beck Depression Inventory, Rosenberg Self-Esteem Scale and Eating Disorder Examination Restraint subscale. The "dietary-depressive" subtype compared to the "dietary" subtype was significantly more likely to: (1) report co-occurring disorders, (2) greater eating and weight concerns, and (3) less vomiting abstinence at post-treatment (all p's<.05). The cluster analysis based on "dietary" and "dietary-depressive" subtypes appeared to have concurrent validity, yielding more distinct groups than subtyping by vomiting frequency. In order to assess the reliability of the subtyping scheme, a larger sample of adolescents with mixed eating and weight disorders in an outpatient eating disorder clinic (N=149) was subtyped, yielding similar subtypes. These results support the validity and reliability of the subtyping strategy in two adolescent samples.

Psychological Treatment of Eating Disorders

Manual-based cognitive behavior therapy (CBT) is presently the most effective treatment of bulimia nervosa. Its efficacy is limited, however. Different strategies for improving upon current manual-based CBT are discussed, including combining CBT with antidepressant medication, integrating CBT with alternative psychological therapies, and expanding the scope and flexibility of manual-based CBT. CBT is underutilized in clinical practice. Dissemination of evidence-based treatment is a priority. Research on anorexia nervosa is minimal. Effective treatments have yet to be developed, although the Maudsley method of family therapy has shown the most promise in the treatment of adolescents. The most commonly seen eating disorders in clinical practice are those classified as "eating disorder not otherwise specified." With the exception of binge eating disorder (BED), however, they have been neglected by researchers. Several psychological therapies have been shown to be effective in treating BED. Controversy exists over whether treatment-specific effects have been identified. Whereas treatments have proved effective in eliminating binge eating and associated eating disorder psychopathology, achieving clinically significant weight loss remains a challenge.