The original cognitive-behavioural model of bulimia nervosa (CBT-BN) proposes that specific dysfunctional cognitions and behavioural factors maintain BN, and has provided the basis for the widely used cognitive-behavioural therapy (CBT) of BN. However, Fairburn et al. (2003) noted that among treatment completers with BN, only 40% achieved full remission of the bulimic symptomatology. The enhanced CBT-BN model (CBT-E) proposed by the authors describes how four additional factors (i.e., clinical perfectionism, low self esteem, mood intolerance and interpersonal difficulties) interact with the core psychopathology of BN (i.e., over-evaluation of eating, weight, and shape and their control) to maintain the disorder.

The goal of this study was to examine (a) the validity of the CBT-E model and (b) whether each of the four hypothesized maintenance factors intensifies the core psychopathology-bulimic symptomatology relationship in a clinical sample.

Data were analysed from 362 adults seeking treatment for BN (n = 167) or atypical BN (n =195) at four Italian specialized care centres, using latent variable structural equation modeling approach.

Both the measurement and the structural model were good fits for the data. All four hypothesized factors exacerbated the core psychopathology-bulimic symptomatology relationship. Core psychopathology explained approximately 47.7% of the variance of bulimic symptomatology. The inclusion of the direct effects and interaction terms increased the explained variance of bulimic symptomatology to 64%.

Overall, results supported the validity of the CBT-E model and highlighted the importance of assessment and treatment of the four maintenance processes included in the CBT-E model.