Past Issues

Objective: In this study, we intended to investigate the effect of methylphenidate on the behavioral performance in a Go/NoGo task in children with attentiondeficit/hyperactivity disorder. Methods: We assessed 16 children with ADHD and 18 healthy controls aged 8 to 12 years. Participants received two separate task sessions, about one month apart. ADHD children were free of medication in the first session and took the regular dosage in the second session, while untreated controls received the identical task in both sessions. We collected and analyzed behavioral data (rates of correct Go trials, reaction times to Go trials, and rates of correct NoGo trials). Results: ADHD children had significantly higher rates of correct Go trials on medication than off medication (p < 0.05). The Go reaction times showed no significant difference with a medium effect size of 0.47 between sessions. We found that the rate of correct NoGo trials was not significantly increased from Session 1 to Session 2 in the ADHD group. Conclusion: The current findings suggest that methylphenidate is effective for enhancing behavioral performance in a Go/NoGo task. Future studies with a larger sample size are warranted.