The purpose of this phase III study is to further evaluate the effects of shenwu capsule, a traditional Chinese herbal medicine, on cognition, function and memory in patients with amnestic mild cognitive impairment (MCI) who are at greater risk for developing Alzheimer's disease, in a 6-month supervised protocol of a traditional Chinese herbal medicine. The results of this study may provide support for a relatively simple and inexpensive treatment strategy with herbal therapy that specifically targets individuals with the mild cognitive impairment that directly influence risk of developing dementia for older adults.

Mild cognitive impairment (MCI) refers to a group of individuals who have some cognitive impairment but of insufficient severity to constitute dementia1,which is a transitional stage between normal aging and dementia. Amnestic MCI is the most common subtype of MCI, which shows the least reversion to normal, and is defined as a significant impairment in memory but with no impairment in activities of daily living. In an interventional study of patients meeting Petersen criteria for amnestic MCI, 16% progressed to dementia per year, 99% of whom received an AD diagnosis. Hence, MCI, in particular amnestic MCI is generally recognized in many cases to represent prodromal AD and becomes a new target for prevention and treatment of AD.

The specific aims for the study is to evaluate change in Efficacy and safety of shenwu capsule in treating amnestic MCI. Using a randomized controlled parallel group design, 324 older adults diagnosed with amnestic MCI participate in a 6-month supervised protocol of either shenwu capsule or donepezil. Cognitive testing and blood collection will occur at baseline, and months 3 and 6. Before the 6-month intervention, medial temporal atrophy (MTA) or hippocampal volume atrophy on the CT or MRI scan are assessed for all subjects. The results of this study may provide support for a safer and inexpensive treatment strategy that specifically targets individuals with the mild cognitive impairment that directly influence risk of developing dementia for older adults.

Inclusion Criteria:

• Chinese-speaking adults at least 55 to 80 years of age old, weighting between 45 to 90 kilograms, living in the community.
• diagnosed with amnestic MCI at screening: (1) memory complaint, corroborated by an informant; (2) abnormal memory function, as screened by the WMS-R Logical Memory II Delayed Story Recall subtest score <10.4 for age; (3) normal general cognitive function, as determined by a clinician's judgment based on a structured interview with the patients (MMSE of 24 to 30 score for education ); (4) no or minimal impairment in activities of daily living, as determined by a clinical interview with the patient and informant (IADL <16 score); and (5) not sufficiently impaired, cognitively and functionally, to meet NINCDS-ADRDA criteria for AD, as judged by an experienced AD research clinician. In addition, they were judged to be at stage 2-3 of the GDS, and to have a score of ≤12 of the HAMD for 17 items, of ≤4 on the HIS, and no or minimal medial temporal atrophy (MTA) or hippocampal volume atrophy on the MRI scan.
• The subjects required adequate vision and hearing to participate in study assessments. Patients receiving chronic aspirin therapy for cardio-protection (≤100 mg per day) or stable doses of antidepressants for at least 3 months were also eligible.

Exclusion Criteria:

• Significant neurologic disease that might affect cognition, such as a diagnosis of Alzheimer's disease, stroke, Parkinson's disease, multiple sclerosis, or severe head injury with loss of consciousness; a score of MMSE<24,or any major psychiatric disorder (e.g., DSM-IV-defined psychosis, major depression, bipolar disorder, or alcohol or substance abuse);
• Recent history of chronic use of NSAIDs or aspirin (>100 mg per day);
• History of upper gastrointestinal bleeding that required transfusion or surgery within the previous 3 years,or documented evidence of an active gastric or duodenal ulcer within the previous 3 months,or history of NSAID-associated ulcers;
• History of active malignancy except for basal cell carcinoma or squamous cell carcinoma of the skin, or prostate cancer, within the preceding 24 months;
• A chronic or acute renal, hepatic, or metabolic disorder; and uncontrolled hypertension and diabetes mellitus;
• History of hypersensitivity to the treatment drugs; or concomitant drugs (including anticonvulsant agents, anti-parkinsonian agents, antipsychotics, anxiolytics, hypnotic agents, neuroleptic agents, cholinomimetic agents, vitamin E, or ginkgo biloba extract or any other drugs including traditional Chinese herbal medicines which can affect memory); or participants in other clinical studies within the past 30 days.

216 in Shenwu capusle, and 108 in the Donepezil group was enrolled at baseline, 1 subjects in both group did not meet the inclusion criteria ,and 215 in Shenwu Capsule, and 107 in Donepezil were used to baseline analysis

Baseline to weeks 24

First, there was no placebo group. As all subjects knew that they were being treated with one of two drugs, and all of the individuals who assessed the patients knew this as well, the results may have been influenced by a positive response bias.