Recent Clinical Trials of Cholinomimetics for Patients with Alzheimer’s Disease in Japan

According to the estimation based on the recent epidemiological investigations of age-associated dementia conducted in Japan (Otsuka et al., 1991), an overall prevalence rate of dementia including institutionalized elderly persons and admitted patients in the population aged 65 years and over was 6.7% in 1990. The number of those with dementia was approximately 994,000. Also, it has been reported that vascular dementia (VD) were more predominant than Alzheimer type dementia (ATD) in Japan (Homma and Hasegawa, 1989). However, Karasawa and Homma (1990) suggested a relatively increased prevalence rate of ATD and a decreased rate of VD probably due to the reduction of cerebrovascular disorders in the elderly persons in survey results conducted in Tokyo in 1980 and 1988. It seems no doubt that ATD will be the most common age-associated dementia in the elderly in Japan. Taking into consideration an extraordinary burden on patients, caregivers and society, effective treatments for ATD patients are urgently required.