Speed of processing and verbal learning deficits in adults diagnosed with attention deficit disorder.

Abstract

While frontal lobe dysfunction has been hypothesized to account for the cognitive and behavioral symptoms characteristic of Attention Deficit Disorder (ADD), inconsistent neuropsychological findings have been reported in adults with residual ADD. Twenty-five ADD adults were compared to 30 gender-, age-, and education-matched healthy controls on measures of sustained attention, psychomotor speed and integration, executive functioning, and verbal learning. There were no group differences in accuracy on the Continuous Performance Task ; however, ADD patients exhibited slower reaction time to targets. In addition, patients exhibited slowed psychomotor speed relative to controls. No group differences were observed in executive functioning. For memory, patients acquired less information and displayed inconsistent application of a semantic clustering strategy. Cuing memory with semantic prompts improved memory performance to a greater degree for patients than for controls. Patients were susceptible to retroactive interference and item recall inconsistency. The results indicate a selective pattern of deficits, revealing slowed cognitive processing and a significant list-learning deficit. Neurobehavioral deficits are discussed in relation to hypotheses of frontal lobe dysfunction in ADD.