An evaluation of the enhanced cognitive-behavioural model of bulimia nervosa

The original cognitive-behavioural model of bulimia nervosa (BN) has been enhanced to include four additional maintaining mechanisms: low self esteem, clinical perfectionism, interpersonal problems, and mood intolerance. These models have been used to guide cognitive-behavioural treatment for BN, but the enhanced model has yet to be directly evaluated as a whole in a clinical sample. This study aimed to compare and evaluate the original and the enhanced cognitive-behavioural models of BN using structural equation modelling. The Eating Disorder Examination and self-report questionnaires were completed by 162 patients seeking treatment for BN (N = 129) or atypical BN (N = 33). Fit indices suggested that both the original and enhanced models provided a good fit to the data, but the enhanced model accounted for more variance in dietary restraint and binge eating. In the enhanced model, low self esteem was associated with greater overevaluation of weight and shape, which, in turn, was associated with increased dietary restraint. Interpersonal problems were also directly associated with dietary restraint, and binge eating was associated with increased purging. While the current study provides support for some aspects of the enhanced cognitive-behavioural model of BN, some key relationships in the model were not supported, including the important conceptual relationship between dietary restraint and binge eating.