Objective: To compare the short- and medium-term effects of psychostimulant medication in children with attention deficit hyperactivity disorder (ADHD).
Methods: Seventy-three children with ADHD participated in a double-blind crossover study of dextroamphetamine (DEX) and methylphenidate (MPH; results previously reported). At the completion of this study, subjects continued to take the preferred stimulant. Subjects were restudied 6-9 months later. The principal outcome measures were the Revised Conners' Parent and Teacher Rating Scales.
Results: Fifty-three families (73%) returned the follow-up surveys. At 6-9 months, mean T scores were still significantly lower than the mean at baseline for all factors of both the CPRS-R and CTRS-R (P < 0.01). There were no statistically significant differences between scores at 6-9 months and scores at the completion of the corresponding medication period in the crossover trial.
Conclusions: After 6-9 months treatment with stimulant medication, ratings remained significantly better than at baseline. This suggests that the early benefits of stimulants are sustained for at least 6 months.