Stimulant treatment with immediate-release methylphenidate (IR MPH) has been demonstrated to improve driving performance in adolescents with ADHD. Simulated driving performance was assessed 1.5 to 2 hours post-dose in a double-blind, crossover study comparing the effects of one 10-mg dose of immediate-release methylphenidate (IR MPH) with placebo in male subjects with ADHD (aged 19-25 years) to that of matched controls without ADHD(Cox 2000). When placebo was administered to both groups, ADHD-diagnosed participants demonstrated significantly poorer driving scores than did controls (P<0.05); however, 1.5 hours after the administration of IR MPH, the driving performance of the ADHD-diagnosed group significantly improved (P<0.05) and was equivalent to that of the control group.