Factor analysis of five adult ADHD self-report measures: are they all the same?

Objective: To test the assumption in the research and assessment of ADHD symptoms that self-report scales measure the same underlying cognitive construct and that there is convergent validity among the scales. The present study specifically tested this assumption by analyzing the scores of 616 individuals on five ADHD self-rating scales using principal components analysis.

Method: Participants completed five self-report scales widely used in the clinical and research communities: the CSS, the BADDS, the CAARS, the AADDES, and the WURS.

Results: Results show that while all scales were highly correlated and loaded onto a single factor solution, the WURS was differentiated from the other four scales best seen through a two factor solution. Therefore, the WURS may also measure other mental and emotional constructs independent from ADHD. Furthermore, participants that reported a previous diagnosis of ADHD scored significantly higher on all measures than those who did not.

Conclusion: Since these scales are in strong agreement with one another in diagnosing ADHD, assessment becomes an issue of which scale is the least time-consuming and most pragmatic for the evaluator to use.