CHANGES IN EVENT-RELATED POTENTIALS WITH STIMULANT MEDICATION IN CHILDREN WITH ATTENTION-DEFICIT HYPERACTIVITY DISORDER

Thirty-two children with attention deficit hyperactivity disorder (ADH D) undergoing a 4 week double-blind medication assessment (methylpheni date) and 32 normal controls were studied using event-related potentia ls (ERPs). The ERPs were recorded from 13 active electrodes during a v isual feature detection task. Significant age effects were found in N2 , P3a and P3b latencies, that did not interact with group. The P3a and P3b latencies were significantly longer in the ADHD children on basel ine testing; there were no latency differences between the groups of c hildren when the normal controls were compared with the ADHD children on their optimal drug dosage (as determined by extensive behavioural a nd cognitive assessments). There were no significant distributional ef fects either between groups, or with the ADHD children as a function o f medication; there were also no significant differences in reaction t ime measures. Thus, only the ERPs reflected slowed processing in the A DHD children that normalized on appropriate medication.