Second childhood

摘要

For most of the 1980s, foreigners looked to Japan as the country of the future. In one respect it still is: it has the highest proportion of elderly people of any large country, a distinction which is accompanied by an exceptionally high rate of dementia, a broad term for defects in memory and cognition concentrated mainly among the elderly. These are diseases of the brain as it ages. After the age of 65, the risk of getting dementia doubles every five years. According to the World Health Organisation, 47.5m people suffer from the condition, of whom about 4.6m are in Japan. The most common form, accounting for more than 60% of all diagnoses, is Alzheimer's disease.