The state of knowledge seemed clear: school education protects against dementia. Every school year is supposed to reduce the risk of developing dementia in later life by up to seven percent. Researchers at the University of Duisburg-Essen (UDE) have shown quite some perseverance and have now refuted this causal connection. Their work is based on a school reform that extended schooling in Sweden 80 years ago. The American Journal of Epidemiology covers this in its current issue.