Evaluating The Efficacy And Safety Of Donepezil Hydrochloride (Aricept) In The Treatment Of The Cognitive Dysfunction Exhibited By Children With Down Syndrome, Aged 11 To 17

All participants will start with a dose of 2.5 mg/day (2.5 ml) donepezil ; dose escalation will occur every 2 weeks to a maximum of 5 mg/day (5 ml) donepezil. All doses will be administered orally.

All participants will start with a dose of 2.5 mg/day (2.5 ml) donepezil ; dose escalations will occur every 2 weeks to a maximum of 10 mg/day (10 ml) donepezil. All doses will be administered orally.

All participants will start with a dose of 2.5 mg/day (2.5 ml) placebo; dose escalations will occur every 2 weeks to a maximum of 10 mg/day (10 ml) placebo. All doses will be administered orally.