Background: At present there are no measures to identify the cognitive processes and behaviours that might mediate the outcome of treatment in people with Body Dysmorphic Disorder (BDD).
Aims: To develop and validate a process measure that can be used to assess the progress of patients throughout therapy and in research for BDD.
Method: The psychometric properties of the Appearance Anxiety Inventory (AAI) were explored in a clinical group of participants diagnosed with BDD (Study 1) and in a non-clinical community group with high appearance concerns (Study 2). Item characteristics, reliability, and factor structure were analysed. Convergent validity with measures of related symptoms was assessed.
Results: The AAI was found to have good test-retest reliability and convergent validity in the measurement of appearance anxiety. It was also sensitive to change during treatment. The scale was found to have a two-factor structure in the clinical group, with one factor characterized by avoidance, and a second factor comprised of threat monitoring. However, in the community sample it appeared to have a one-factor structure.
Conclusion: The results suggest that the AAI has the psychometric properties to determine whether changes in cognitive processes and behaviours can mediate the outcome following treatment in patients with BDD. This supports its potential usefulness in clinical and research settings.