After a 1-month single-blind run in phase, 910 subjects will be titrated, over a period of up to 8 weeks, to target doses of either: 0 (placebo); 24 mg/day galantamine; 16 mg/day galantamine; or 8 mg/day galantamine, in a 2:2:2:1 randomization ratio. Double-blind treatment will continue for a total of 5 months. The change from baseline in ADAS-cog and CIVIC-plus scores at Month 5 will be the primary efficacy endpoints. Tolerability will be evaluated based on adverse event reports, laboratory values, ECG, and vital signs with particular focus on the adverse event rates in the slower titration schedule for 24 mg/day. Efficacy of 24 mg/day and 16 mg/day galantamine will be compared with that of placebo. Information on the dose response relationship of galantamine will be evaluated.