Diagnostic Accuracy of the Conners' Adult ADHD Rating Scale in a Postsecondary Population.

Clinicians frequently rely upon the results of self-report rating scales when making the diagnosis of ADHD; however, little research exists regarding the ability of self-report measures to accurately differentiate ADHD from other disorders. This present study investigated the ability of the Conners' Adult ADHD Rating Scale (CAARS) to discriminate between 249 postsecondary students with carefully diagnosed ADHD and 507 clinical controls. The overall discriminant validity of the CAARS was 69%, and it had an unacceptably high false positive and false negative rate. At lower prevalence rates, a high score on the CAARS has only a 22% chance of accurately identifying individuals with ADHD. Although the CAARS is an adequate screening measure, it should not be the main method by which a diagnosis is made, as it frequently misidentifies individuals with other psychological complaints as having ADHD. Implications for clinical practice are discussed.