Test of variables of attention performance among ADHD children with credible vs. non-credible PVT performance

The assessment of effort is a crucial step in the evaluation of children and adolescents who present with symptoms of an Attention-Deficit/Hyperactivity Disorder (ADHD). Studies with adults have found that a large percentage of individuals claiming to have ADHD fail performance validity measures. In children, failure on PVT measures is associated with lower scores on a wide array of neuropsychological measures. The current study examined the performance of 50 children diagnosed with ADHD on the basis of whether they passed (N = 25) versus failed (N = 25) a standalone PVT, on the Test of Variables of Attention (TOVA), the Wisconsin Card Sorting Test - 64 (WCST) and the Tower of London: Drexel (TOL). Subjects who failed one or more PVTs scored significantly below those who passed, on the Omission scores of the TOVA and on several dimensions of the WCST. No significant differences were found on the TOL scores. Specifically, subjects who failed PVTs scored more than two standard deviations below the mean on the first half TOVA Omission errors score, whereas those who passed PVTs scored within the Average range. It is proposed that first half Omission scores on the TOVA may represent an embedded measure of effort.