Qinggongshoutao Bolus

This study is a 52-weeks, multicenter, randomized, double-blind, double- placebo, parallel controlled phase VI trial being carried out in 20 centers around China. The study population includes amnestic mild cognitive impairment patients (planned a total of 360) aged 55-85 in both gender. Participants will be randomly allocated to Qinggongshoutao bolus (7g per time,2 times per day) and placebo identified to Ginkgo biloba (Ginaton), Ginkgo biloba (Ginaton) (80mg per time, 2 times per day) and placebo identified to Qinggongshoutao bolus, or placebo identified to Qinggongshoutao bolus and placebo identified to Ginkgo biloba (Ginaton) for a 52-weeks double-blind treatment period. The primary outcome measure is change from baseline in the Alzheimer's Disease Assessment Scale- Cognition Subscale (ADAS-cog) and rate of conversion to dementia. The secondary outcomes are changes from baseline in the Mini-Mental State Examination(MMSE), Delayed Story Recall(DSR), Alzheimer's Disease Cooperative Study/Activities of Daily Living scale adapted for MCI patients (ADCS/MCI/ADL24). Safety is being assessed by observing side effects and adverse reaction during the entire treatment period. Statistical analysis will be conducted according to per-protocol population and intend-to-treat population and the safety will be analyzed in safety set.