Researchers analyzed 1,712 former NFL players who died between 2008 and 2021, including 338 brain donors, to estimate the possible prevalence of chronic traumatic encephalopathy (CTE) at death and its association with dementia. At least 24.5% of players who died from 2016 to 2021 had confirmed CTE, while stage IV CTE among brain donors was associated with a 44% higher risk of clinician-adjudicated dementia.