Thought-shape fusion in anorexia nervosa: an experimental investigation.

Cognitive biases and cognitive distortions have been implicated as important factors in the development and maintenance of many disorders. The concept of thought-shape fusion (TSF) in eating disorders was developed by Shafran, Teachman, Kerry, and Rachman (British Journal of Clinical Psychology 38 (1999) 167) as a variant of thought-action fusion, described by Shafran, Thordarson and Rachman (Journal of Anxiety Disorders 10 (1996) 379). TSF occurs when thinking about eating certain types of food increases a person's estimate of their shape and/or weight, elicits a perception of moral wrongdoing, and/or makes the person feel fat. Shafran et al. (1999) examined both the psychometric and experimental properties of TSF in an undergraduate sample. This paper reports an extension of this work to a clinical group (N=20) of patients with anorexia nervosa. After completing a set of relevant questionnaires, participants were asked to think about a food which they considered extremely fattening. They were then asked to write out the sentence, "I am eating--.", inserting the name of the fattening food in the blank. After being asked to rate their anxiety, guilt, feelings about their weight, morality, etc., participants were given the opportunity to neutralize their statement in any way they chose. The majority of the participants neutralized in ways consistent with the findings of Shafran et al. (1999). The results are discussed in terms of cognitive-behavioural formulations of eating disorders, and of the influence of cognitive biases and cognitive distortions on the processing of information relevant to food, weight and shape in anorexia nervosa.