Transdiagnostic features of bulimia nervosa and binge eating disorder

The transdiagnostic cognitive behavioural theory of eating disorders (Fairburn, Cooper, & Shafran, 2003) is a relatively new theory, which attempts to describe how all eating disorders, including Bulimia Nervosa (BN) and Binge Eating Disorder (BED), are maintained. The theory suggests that in certain patients, core psychopathology interacts with one or more of four additional maintenance mechanisms which further maintain the eating disorder, thereby obstructing change. The four proposed maintenance factors include the role of a particular type of perfectionism, clinical perfectionism; difficulty in tolerating strong mood states, or mood intolerance; interpersonal difficulties; and an extremely low self-esteem, termed core low self-esteem. This series of studies examines both the cognitive and behavioural processes involved in the core psychopathology of eating disorders, and the additional proposed maintenance mechanisms in BN and BED. The overall aim of these studies is to investigate whether the additional processes described by the transdiagnostic cognitive behavioural theory of eating disorders (Fairburn et al., 2003) operate in BN and BED, thereby providing a more comprehensive account of the maintenance of these eating disorders. The first study used questionnaires to assess features of the transdiagnostic cognitive behavioural model of eating disorders (Fairburn et al., 2003) in a group of 20 participants with BN and 15 with BED. These groups were compared to control groups of 20 participants each who were normal weight (NW) and overweight (OW) but not eating disordered. It was followed by two studies examining the cognitive processes maintaining disturbed and disordered eating. The second study examined memory biases to eating, shape, weight and achieving perfection in disturbed eaters using six groups of 20 participants, varying by levels of dietary restraint, whether or not they were currently dieting and whether they were NW or OW. The third study examined attentional bias (using a modified visual probe task) towards the same kind of information in the disordered eaters from the first study. Overall, the results of the studies indicated that individuals with BED and BN exhibit similar features, which supports the notion of similar maintenance factors across eating disorders proposed by the transdiagnostic cognitive behavioural theory (Fairburn et al., 2003). Both mood intolerance and interpersonal difficulties were identified to be specific maintenance factors in these eating disorders. While perfectionism and low self-esteem were identified in high levels for both eating disorders, the nature of clinical perfectionism and core low self-esteem requires further investigation. In relation to the cognitive tasks, a differential memory bias for eating, shape, weight and achieving perfectionism was evident for those who were high in dietary restraint in comparison to those who were currently dieting suggesting that cognitive processes play a role in the maintenance of disturbed eating. It was followed by findings that the BN and BED groups exhibited a similar attentional bias effect, with a characteristic hypervigilance-avoidance response to information that was congruent with beliefs about eating, shape, weight and perfectionism. This series of studies provided support for BN and BED being adequately described by the transdiagnostic cognitive behavioural theory of eating disorders (Fairburn et al., 2003). The implications of these results are discussed in relation to the diagnostic status of BED, the transdiagnostic theory of eating disorders and the implications of identification and management of these disorders.