Clinical and psychometric validation of an extended version of the Testable Assumptions Questionnaire (TAQ-ED-R)

Testable dysfunctional assumptions are a central aspect of the cognitive profile of patients with eating disorders. These are conditional beliefs that can be challenged directly using techniques such as behavioural experiments and surveys. Recent research has suggested that such assumptions fall into three classes (assumptions about one's body, one's feelings and the world), but the emerging scale had only relatively few items. The present study examines the clinical and psychometric utility of an extended version of that scale--the Testable Assumptions Questionnaire-Eating Disorders-Revised (TAQ-ED-R).

The TAQ-ED-R and the Eating Disorders Examination-Questionnaire (EDE-Q) were administered to 200 women--72 with eating disorders, and 128 with no eating disorder. Differences between anorexic, bulimic and non-clinical women were examined, and associations with EDE-Q scores were tested.

The three subscales had adequate to good internal consistency across all three samples. The two clinical groups reported relatively high levels of testable assumptions, but there was no difference between the anorexic and bulimic women on the overall scale. Although all three forms of testable assumption were associated with levels of eating pathology, assumptions relating to one's body were the key correlate.

The TAQ-ED-R is a clinically useful measure of dysfunctional assumptions that can be tested with the help of behavioural experiments and surveys. It will be important to test the predictive validity of the new measure, as well as its capacity to drive treatment for comorbid states, such as alexithymia and social anxiety.