Psychometric properties of the dimensional anxiety scales for DSM-V in an unselected sample of German treatment seeking patients.

BACKGROUND: Dimensional assessments are planned to be included as supplements to categorical diagnoses in DSM-V. The aim of this study was to examine the unidimensionality, reliability, validity, and clinical sensitivity of brief self-rated scales for specific anxiety disorders in an unselected German sample of consecutive attendees to a psychological clinic. These scales use a common template to assess core constructs of fear and anxiety.
METHODS: Dimensional scales for social anxiety disorder, specific phobia, agoraphobia, panic disorder, and generalized anxiety disorder were administered along with established scales to 102 adults seeking treatment for mental health problems at a German university outpatient clinic for psychotherapy. The computer-assisted clinical version of the Munich-Composite International Diagnostic Interview was used to assess mental disorders according to DSM-IV criteria. Dimensionality and scale reliability were examined using confirmatory factor analyses. Convergent and discriminant validity were examined by testing differences in the size of correlations between each dimensional anxiety scale and each of the previously validated scales. Each dimensional scale's ability to correctly differentiate between individuals with versus without an anxiety diagnosis was examined via the area under the curve.
RESULTS: Analyses revealed unidimensionality for each scale, high reliability, and convergent and discriminant validity. Classification performance was good to excellent for all scales except for specific phobia.
CONCLUSIONS: The application of the dimensional anxiety scales may be an effective way to screen for specific anxiety disorders and to supplement categorical diagnoses in DSM-V, although further evaluation and refinement of the scales (particularly the specific phobia scale) is needed.