Outcome predictors for the cognitive behavior treatment of bulimia nervosa: Data from a multisite study

Objective: The aim of this study was to discover clinically useful predicto rs of attrition and outcome in the treatment of bulimia nervosa with cognit ive behavior therapy. Method: Pretreatment, course of treatment, and outcome data were gathered o n 194 women meeting the DSM-III-R criteria for bulimia nervosa who were tre ated with 18 sessions of manual-based cognitive behavior therapy in a three -site study. Differences between dropouts and nondropouts and between recov ered and nonrecovered participants were first examined descriptively, and s ignal detection analyses were then used to determine clinically significant cutoff points predicting attrition and abstinence. Results: The dropouts were characterized by more severe bulimic cognitions and greater impulsivity, but it was not possible to identify clinically use ful predictors. The participants with treatment failures were characterized by poor social adjustment and a lower body mass index, presumably indicati ng greater dietary restriction. However, early progress in therapy best pre dicted outcome. Signal detection analyses revealed that poor outcome was pr edicted by a reduction in purging of less than 70% by treatment session 6, allowing identification of a substantial proportion of prospective failures . Conclusions: A cutoff point based on reduction of purging by session 6 usef ully differentiates patients who will and will not respond to cognitive beh avior therapy for bulimia nervosa, potentially allowing early use of a seco nd therapy.