A change of mind: the Conners abbreviated rating scales reconsidered.

A cutoff score of 15 on the Conners 10-item Abbreviated Teacher Rating Scale (ATRS), based on a study from this laboratory, has been widely used by investigators for diagnosis of the syndrome known now as Attention Deficit Disorder with or without Hyperactivity. A replication of the original research employing a larger norm sample indicates that the suggested score of 15 is too low. Comparing the norm sample with hyperactive subjects selected by cutoff of 15 on the ATRS showed that the groups differed greatly on hyperactivity but not on inattention. The abbreviated form of the Conners scale does not effectively select children with attention deficits. Numerous problems with both the 39-item teacher scale and the abbreviated form suggest strongly that they be abandoned as research tools.