All cohort-level analyses were restricted to European-ancestry individuals that passed the cohort’s quality control and whose EduYears was measured at an age of at least 30. The EduYears phenotype was constructed by mapping each major educational qualification that can be identified from the cohort’s survey measure to an International Standard Classification of Education (ISCED) category and imputing a years-of-education equivalent for each ISCED category. Details on cohort-level phenotype measures, genotyping, imputation, association analyses, and quality-control filters are described in Supplementary Tables 16–19.
