The chemical is used as the starting point for other drugs, including nicergoline, a treatment for senile dementia.

ECONOMIST: LSD

This raises problems for pensions (Japan has a pay-as-you-go system) and health care (the number of people with senile dementia is set to reach 2.6m in 2015, up from 1m in 1990).

ECONOMIST: Social conventions and demography add to the sclerosis

In 2002, after the Chilean supreme court ruled that senile dementia made him unfit to face trial, he was forced to resign his Senate seat too (even senators-for-life need to be compos mentis).

ECONOMIST: Chile's new constitution