JAMA Study: At Least 1 in 4 Former NFL Players Had CTE

A JAMA study published August 25, 2026 found at least 1 in 4 former NFL players who died between 2016 and 2021 had CTE, a degenerative brain disease diagnosable only after death. Of 878 deceased players, 235 brains were donated; 215 had CTE. Researchers from Mass General Brigham and Boston University called it the first population-level estimate. Lead author Daniel Daneshvar noted NFL players die from neurodegenerative disease at roughly four times the general-population rate.