Discriminant validity of the Wender Utah Rating Scale for attention-deficit/hyperactivity disorder in adults.

The authors examined the factor structure and discriminant validity of the Wender Utah Rating Scale (WURS) in adults seeking evaluation for attention-deficit/hyperactivity disorder (ADHD). Three factors (Dysthymia, Oppositional/Defiant Behavior, and School Problems) accounted for 59.4% of the variance. In a stepwise discriminant function analysis, age and childhood school problems emerged as significant variables. The classification procedure correctly classified 64.5% of patients. Among those who did not have ADHD, only 57.5% were correctly classified compared with 72.1% among those with ADHD. The WURS is sensitive in detecting ADHD, but it misclassifies approximately half of those who do not have ADHD.