Event-related potentials study in attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is a childhood disorder characterized by lack of sustained attention, hyperactivity and impulsivity. Children with ADHD have functional impairment occurring at multiple levels. In the present study, cognitive status was assessed using auditory event-related potentials (ERPs). Twenty ADHD children and 20 controls were recruited for the study and ERPs were recorded on a computerized evoked potential recorder, using the international 10-20 system of electrode placement. The ADHD children showed a statistically significant N200 latency prolongation and amplitude decrease compared with the controls; the latencies of the other waves, i.e. N100, P200, P300, were prolonged in the ADHD children but the difference versus the controls was statistically insignificant. Reaction time was significantly longer in the ADHD subjects as compared with the controls. The above findings are suggestive of dysfunctions in the discrimination of task-relevant stimuli and a slower motor response in ADHD children.