Detailed Description:

Dementia is a chronic, progressive neurodegenerative syndrome, characterized by an abroad category of non-reversible impairment in cerebral function, making a long-term and gradual decrease in the ability to mental cognitive tasks and performance of daily activities. The World Health Organization says that 47.5 million people around the world are living with dementia. Alzheimer's disease is accounting for 60-70 percent, the most common type of dementia. According to the record from the Ministry of Health and welfare in Taiwan, the population over 65-year-old is more than 3.36 million. It is estimated that there are more than 250,000 people with mental disabilities and nearly 600,000 people with mild cognitive impairment. With the aging of the population, experts predict that the number of patients suffering from Alzheimer's disease will be up to 800,000. In 2016, a study based on the health insurance database from 1997 to 2008 in Taiwan showed that 78.2 percent of patients have received Chinese medicine treatment, such as herbal medicine and acupuncture after diagnosed as Alzheimer's disease. Therefore, this clinical trial is designed as a randomized, double-blinded, placebo-controlled, crossover clinical trial that aims to investigate the effect of VGH-AD1, traditional Chinese herbal medicine powder, on Alzheimer's disease. Participants will be randomized allocated 14 participants into each group A and B. Group A will receive VGH-AD1, while group B will receive a placebo two times per day for eight weeks. Then entry two weeks wash-out period. And then two groups will be switched for another eight weeks. Post-study follow up will be 4 weeks after the intervention end. The study duration is totally 22 weeks. All participants will be assessed by the MMSE, IADL, NPI-Q, IQCODE, GDS, QOL-AD, TCM50, which will be conducted at baseline, week 8,10,18 and 22.}}