Efficiently assessing negative cognition in depression: an item response theory analysis of the Dysfunctional Attitude Scale.

Despite a central role for dysfunctional attitudes in cognitive theories of depression and the widespread use of the Dysfunctional Attitude Scale, form A (DAS-A; A. Weissman, 1979), the psychometric development of the DAS-A has been relatively limited. The authors used nonparametric item response theory methods to examine the DAS-A items and develop a briefer version of the scale. Using DAS-A data obtained from depressed participants enrolled in 2 large depression treatment studies (N=367), the authors developed a 9-item DAS form (DAS-SF1). In addition, because 2 versions of the DAS are needed for certain study designs, they also developed a 2nd short version (DAS-SF2). These short forms were highly correlated with the original 40-item DAS-A (rs ranged from .91 to .93), exhibited change similar to that of the DAS-A over the course of treatment, were moderately correlated with related self-report assessments, predicted concurrent depression severity, and predicted change in depression from before to after treatment. Taken together, the authors believe the DAS-SF1 and DAS-SF2 provide an efficient and accurate assessment of dysfunctional attitudes among depressed individuals.