In this JAMA article, Kenneth Langa, Eric Larson, Eileen Crimmins, Jessica Faul, Deborah Levine, Mohammed Kabeto, and David Weir report on findings from their recent study of dementia in the US. Using cohort data from the Health and Retirement Study, which collects information on older Americans’ health, cognitive abilities, and life circumstances, they found that the prevalence of dementia declined significantly between 2000 and 2012. The decline they found – from 11.6% to 8.8% – translates to about 1 million fewer Americans with the condition. They attribute some of the improvement to increasing educational attainment among older Americans and better control of cardiovascular risk factors for dementia.