Implementation and predictive capacity of CBT coping strategies in individuals with bulimia nervosa

Background. The efficacy of cognitive behavioral therapy (CBT) for bulimia nervosa (BN) has been well established. However, despite considerable research devoted to the identification of CBT prognostic indicators, few robust variables have been found to predict CBT response or relapse. Interestingly, little is known about whether individuals with bulimia nervosa (BN) actually implement strategies to overcome BN. Objective. To examine the extent to which CBT participants report implementing strategies to overcome BN and to assess the predictive utility of such strategies. Methods. Participants were women (N = 143) with BN enrolled in a group CBT study. The primary measure was a modification of the Coping Scale, adapted to assess frequency of strategies used to abstain from BN behaviors. Additional measures included the Eating Disorders Questionnaire (EDQ), Eating Disorders Inventory (EDI), Beck Depression Inventory (BDI), and Eating Behaviors-III (EB-III). Results. The Coping Scale was subjected to a principal-components analysis with varimax rotation, which yielded a 3 factor solution: cognitive (COG), stimulus-response prevention (SRP), and interpersonal (INT). Frequency of the composite (COM; t = 13.67), COG (t = 10.41), SRP (t = 11.34), and INT (t = 12.49) coping scores significantly increased pre- to post-treatment (all p's < .001). However, results of hierarchical multiple logistic regression analyses indicated that utilization of coping strategies at end of CBT did not improve upon prediction of 1-month BN symptom remission after accounting for treatment condition and end of treatment measures of BN symptom severity, BDI total score, and EDI Perfectionism and Interpersonal Distrust scores. By 1-month follow-up, the COM score declined significantly (t = -3.13, p = .002), which appears to be due to reductions in use of INT ( t = -4.49, p < .001) rather than COG ( t = -1.07, p = .29) or SRP (t = -1.67, p = .10) methods. INT coping use at 1-month follow-up significantly predicted 6-month BN symptom remission (B = .21, Wald (1) = 4.72, p = .03). Discussion. BN coping strategies were found to increase by end of treatment, which lends support to our understanding of the mechanisms of action of CBT. Although coping strategy use at treatment completion did not predict relapse, use of INT at 1-month significantly predicted 6-month remission, which highlights the importance of interpersonal support to maintain treatment gains.