The investigation of P300 in children with attention deficit hyperactivity disorder before and under methylphenidate treatment

Objective The aims of the present study were to investigate latency and amplitude of N1,P2,N2 and P300 in parietal and frontal areas in children with attention deficit hyperactivity disorder(ADHD),and to determine the effect of methylphenidate(MPH)on these event-related potential(ERPs)indices in ADHD group.Methods The children with ADHD were divided into two groups at random:the children of one group were treated with methylphenidate,and the children of the other group were offered placebo(control group).The ERPs was elicited using an auditory two-stimulus oddball paradigm.Efficacy and P300 data from 60 children with ADHD enrolled in a double-blind crossover study using methylphenidate and placebo were analyzed.The correlation analysis revealed correlation in the P300 latency ratio before and under methylphenidate treatment.Results Before MPH treatment,no significant difference was found in N1,P2,N2 andP300 between two groups.MPH treatment resulted in a significantly shorter latency in P300;there was no significant difference in N1,P2,N2 before MPH and under MPH treatment in ADHD subjects(all P values 0.05).Under MPH treatment,the amplitude of P300 was not significantly different(all P values 0.05).Conclusion The ratio of parietal auditory P300 latency predicts response to stimulants in patients with ADHD.Tests such as this may help pinpoint whether to use a stimulant or some other mechanism of action.So P300 topography can be used to select optimal treatment.