Rapid Response to Day Hospital Treatment in Bulimia Nervosa and Purging Disorder: a Randomized Controlled Trial of an Intervention to Facilitate Early Behaviour Change

Even the most effective treatments for bulimia nervosa and purging disorder have high rates of nonremission and relapse. As such, improving treatment efficacy is an important research priority in this area. Research has consistently demonstrated that rapid response – defined as substantial improvements in key eating disorder behaviours (e.g., binge eating, vomiting, dietary restriction) during the initial weeks of cognitive behavioural therapy (CBT) – is the strongest and most robust predictor of good outcomes at end-of-treatment and in follow-up (Vall & Wade, 2015). Further, research has failed to identify pre-treatment demographic or clinical variables that account for this relationship, suggesting that rapid response is due to elements of CBT itself. This study aimed to demonstrate that rapid response can be clinically facilitated. A four-session CBT intervention focused on encouraging rapid response was compared to a matched-intensity motivational interviewing intervention, both adjunctive to intensive treatment in a randomized controlled trial. The CBT intervention included psychoeducation about rapid response, a focus on goal-setting, and use of behavioural skills for making concrete changes. Forty-four women with bulimia nervosa or purging disorder participated in the study. There were no baseline differences between groups on any demographic or clinical variables. Intent-to-treat results showed that compared to those who received motivational interviewing, participants who received CBT were significantly more likely to make a rapid response to day hospital treatment, and had fewer total eating disorder behaviours and more normalized eating during the first 4 weeks of day hospital treatment. Additionally, between baseline and day hospital end-of-treatment, participants who received CBT made significantly greater improvements on overvaluation of weight and shape and difficulties with emotion regulation. These findings indicate that rapid response to intensive treatment can be clinically facilitated using an adjunctive intervention focused on encouraging rapid and substantial change. These findings also suggest that rapid response may be related to improved outcome via improvements in overvaluation of weight and shape or emotion regulation. This study provides support for theoretical contentions that rapid response is due to CBT-related factors, and provides the framework for future research investigating rapid response as a causal mechanism of good outcome for eating disorders.

Rapid Response to Day Hospital Treatment in Bulimia Nervosa and Purging Disorder: a Randomized Controlled Trial of an Intervention to Facilitate Early Behaviour Change

Even the most effective treatments for bulimia nervosa and purging disorder have high rates of nonremission and relapse. As such, improving treatment efficacy is an important research priority in this area. Research has consistently demonstrated that rapid response – defined as substantial improvements in key eating disorder behaviours (e.g., binge eating, vomiting, dietary restriction) during the initial weeks of cognitive behavioural therapy (CBT) – is the strongest and most robust predictor of good outcomes at end-of-treatment and in follow-up (Vall & Wade, 2015). Further, research has failed to identify pre-treatment demographic or clinical variables that account for this relationship, suggesting that rapid response is due to elements of CBT itself. This study aimed to demonstrate that rapid response can be clinically facilitated. A four-session CBT intervention focused on encouraging rapid response was compared to a matched-intensity motivational interviewing intervention, both adjunctive to intensive treatment in a randomized controlled trial. The CBT intervention included psychoeducation about rapid response, a focus on goal-setting, and use of behavioural skills for making concrete changes. Forty-four women with bulimia nervosa or purging disorder participated in the study. There were no baseline differences between groups on any demographic or clinical variables. Intent-to-treat results showed that compared to those who received motivational interviewing, participants who received CBT were significantly more likely to make a rapid response to day hospital treatment, and had fewer total eating disorder behaviours and more normalized eating during the first 4 weeks of day hospital treatment. Additionally, between baseline and day hospital end-of-treatment, participants who received CBT made significantly greater improvements on overvaluation of weight and shape and difficulties with emotion regulation. These findings indicate that rapid response to intensive treatment can be clinically facilitated using an adjunctive intervention focused on encouraging rapid and substantial change. These findings also suggest that rapid response may be related to improved outcome via improvements in overvaluation of weight and shape or emotion regulation. This study provides support for theoretical contentions that rapid response is due to CBT-related factors, and provides the framework for future research investigating rapid response as a causal mechanism of good outcome for eating disorders.

Weight suppression increases odds for future onset of anorexia nervosa, bulimia nervosa, and purging disorder, but not binge eating disorder

ABSTRACT Background Eating disorders affect 13% of females and contribute to functional impairment and mortality, but few studies have identified risk factors that prospectively correlate with future onset of anorexia nervosa (AN), bulimia nervosa (BN), binge eating disorder (BED), and purging disorder (PD). Identifying risk factors specific to each eating disorder is critical for advancing etiologic knowledge and designing effective prevention programs. Objectives This study examined whether weight suppression (the difference between a person's highest past weight at their adult height and their current weight) correlates with future onset of AN, BN, BED, and PD. Methods Data from 1165 young women with body image concerns (mean ± SD age: 21.9 ± 6.4 y) who completed annual diagnostic interviews over a 3-y follow-up period were examined. Logistic regression models evaluated the relation of baseline weight suppression to onset risk of each eating disorder controlling for age, dietary restraint, and intervention condition. Results Elevated weight suppression predicted future onset of AN (OR: 1.36; 95% CI: 1.03, 1.80), BN (OR: 1.34; 95% CI: 1.11, 1.62), PD (OR: 1.46; 95% CI: 1.23, 1.74), and any eating disorder (OR: 1.32; 95% CI: 1.12, 1.56), but not BED (OR: 1.10; 95% CI: 0.89, 1.37). Highest past weight correlated with future onset of BN and PD but not onset of AN, BED, or any eating disorder, and baseline current weight was inversely related to future AN onset only, implying that women with the largest difference between their highest past weight and current weight are at greatest risk of eating disorders. Conclusions The results provide novel evidence that weight suppression correlates with future onset of eating disorders characterized by dietary restriction or compensatory weight control behaviors and suggest weight-suppressed women constitute an important risk group to target with selective prevention programs. These trials were registered at clinicaltrials.gov as NCT01126918 and NCT01949649.

Feeling Sick

Eating is fundamental to our survival and subject to numerous biological regulators that influence when, what, and how much we eat. This makes biological factors central to any answer for why someone develops purging disorder. Genetic factors impact body weight and temperament and may even influence a person’s susceptibility to nausea and vomiting. Yet data from family and twin studies suggest that genes may play a slightly smaller role in risk for purging disorder compared to other eating disorders. Instead, biological responses to food intake may explain the unique configuration of purging after consuming normal amounts of food in purging disorder. Compared to those with bulimia, individuals with purging disorder have greater release of hormones that trigger the brain to stop eating. Compared to those with bulimia and those without an eating disorder, individuals with purging disorder release excessive amounts of a hormone that triggers feelings of nausea and stomachache.

What Happens in Treatment

Effective treatment requires a team of health professionals working together. Team members should include, at minimum, a physician, a dietitian, and a therapist. Many treatments begin with psychoeducation to explain what maintains purging disorder, the consequences of the illness, and why a chosen therapy facilitates recovery. This chapter describes therapies that have been used to treat patients with purging disorder, including family-based treatment in adolescents, cognitive-behavioral therapy in adolescents and adults, and integrated cognitive affective therapy in adults. Most treatments require adaptation to effectively address purging as a primary symptom rather than as a response to binge eating. At this time, there are no randomized controlled trials focused on treatment for purging disorder. This means clinicians bear the responsibility of identifying a first line of treatment for their patients with purging disorder and evaluating the treatment’s effectiveness.