Childhood Cognitive Ability and Incident Dementia: The 1932 Scottish Mental Survey Cohort into their 10th Decade.

Background: The prevention of dementia is a global priority but its etiology is poorly understood. Early life cognitive ability has been linked to subsequent dementia risk but studies to date have been small and none has examined sex differences.

Methods: In the 1932 Scottish Mental Survey cohort, we related intelligence test scores at age 11 years in 16,370 boys and 16,097 girls (born in 1921) to incident dementia ages ≥65 years as ascertained using probabilistic linkage to electronic health records up to the age of 92 years (1,231 cases in men, 2,163 in women; median follow-up 15 years).