This is an ancillary study to the ongoing CARDIA study of 5,115 adults who recently completed their seventh (year 25) follow-up, in which cognitive testing was measured, and will be participating in a year 30 exam in 2015-16. The specific aims are: 1) Using repeated measures collected over 30 years, to determine the association between cardiovascular (CV) risk factors in young adulthood on cognitive function (CF) and 5-year change in CF at mid-life. 2) To determine the association between measures of metabolic regulation, oxidative stress and adiposity in young adulthood on CF and 5-year change in CF at mid-life. 3) To use GWAS data in order to identify novel common and rare genetic variants, particularly on pathways of CV disease and metabolic regulation, associated with CF and decline. 4) To determine if there are race/ethnic difference in the association between risk factors and CF and if so, if they are moderated by socio-economic status, education, literacy and other disparities.