Development and preliminary validation of the testable assumptions questionnaire--eating disorders (TAQ-ED)

While cognitive formulations of eating disorders emphasise the role of dysfunctional assumptions regarding eating, weight and shape (EWS), less is known about the role of dysfunctional assumptions that are unrelated to EWS and those linking beliefs about EWS with negative beliefs about the self or the world. The present study aimed to develop a brief measure of dysfunctional assumptions in the eating disorders and to validate it clinically. Given that cognitive-behavioural therapy frequently involves the testing of patients' assumptions with the help of behavioural experiments, the measure was designed specifically to assess assumptions that can be addressed using such techniques.

The sample consisted of 79 women with DSM-IV eating disorder diagnoses. Each participant completed the measure of testable assumptions in the eating disorders (TAQ-ED), the Eating Disorders Inventory (EDI) and the Brief Fear of Negative Evaluation scale (Brief FNE).

The TAQ-ED was made up of three scales, each of which had acceptable psychometric properties. High scores on the eating attitudes/behaviours scales of the EDI and on the Brief FNE were broadly associated with dysfunctional assumptions about the world and one's body. In contrast, high scores on ego-dysfunction scales of the EDI were associated with dysfunctional assumptions about feelings.

Different aspects of eating disorder pathology appear to be linked to different types of dysfunctional assumptions in the eating disorders. The clinical value of the proposed new measure of dysfunctional assumptions is discussed, and ideas are provided for behavioural experiments testing such assumptions.