Neuropsycho-epidemiologic study on aging and dementia in Japan: The Tajiri Project

One conception of aging and cognitive deterioration is that cognitive decline becomes common with age, and dementia may be regarded as one extreme of the continuum. An alternative conception is that the cognitive process is spared by the aging process itself and that cognitive functioning of healthy older adults and those with slight cognitive impairment, a Clinical Dementia Rating (CDR) score of 0.5, should be different. Since 1988, we have been performing the Tajiri Project, i.e., a community-based study on stroke, dementia, and bed-confinement prevention for older adults aged 65 years and over in Tajiri, Miyagi Prefecture, a typical agricultural area in northern Japan. The project needs an integrated approach of neurology, neuropsychology, neuropsychiatry, neuroimaging, and neuroepidemiology. We herein review the main findings of the project.