3-year study of donepezil therapy in Alzheimer's disease : Effects of early and continuous therapyDepartment of Psychiatry, Institute of Brain and Behaviour, Maastricht Hospital University, Maastricht, PAYS-BAS Delays in the diagnosis of Alzheimer's disease, and, therefore, delays in treatment, may have a detrimental effect on a patient's long-term well-being. This study assessed the effects of postponing donepezil treatment for 1 year by comparing patients treated continuously for 3 years with those who received placebo for 1 year followed by open-label donepezil for 2 years. Patients (n = 286) with possible or probable Alzheimer's disease (according to DSM-IV, NINCDS-ADRDA, and Mini-Mental State Examination criteria; see text) were randomized to receive donepezil (5 mg/day for 4 weeks, 10 mg/day thereafter) or placebo (delayed-start group) for 1 year. Of the 192 completers, 157 began a 2-year, open-label phase of donepezil treatment. Outcome measures were the Gottfries-Br?ne-Steen scale, the Mini-Mental State Examination, the Global Deterioration Scale, the Progressive Deterioration Scale, the Neuropsychiatric Inventory, and safety (adverse events). Mixed regression analysis was used to compare changes between the groups over 3 years on the efficacy measures. There was a trend for patients receiving continuous therapy to have less global deterioration (Gottfries-Brane-Steen scale) than those who had delayed treatment (p = 0.056). Small but statistically significant differences between the groups were observed for the secondary measures of cognitive function (Mini-Mental State Examination; p = 0.004) and cognitive and functional abilities (Global Deterioration Scale; p = 0.0231) in favor of continuous donepezil therapy. Over 90% of the patients in both cohorts experienced one treatment-emergent adverse event; most were considered mild or moderate.