Overview
- The study, published Oct. 28, 2026 in JAMA Network Open, analyzed medical records for 2,362 former NFL players who died from 2008 through 2023 and adjusted for brain‑donation bias to estimate disease prevalence.
- Among 387 donated brains in the sample nearly 94 percent showed CTE pathology, and after correcting for the tendency of symptomatic families to donate the team calculated a 74.5 percent estimated prevalence in the studied cohort.
- Researchers also estimated that roughly one in four players in the cohort had dementia, a condition commonly seen in later stages of CTE and a sign of substantial long‑term cognitive burden.
- CTE remains diagnosable only at autopsy because definitive identification requires observing abnormal tau protein patterns in brain tissue, a limitation that skews research toward symptomatic cases and complicates efforts to measure living prevalence.
- Players acknowledged the risk but continue to play, the NFL reiterated its safety work, and scientists urged steps such as limiting full‑contact practices, reducing cumulative impacts at youth and pro levels, developing in‑life diagnostics, and increasing care and research funding.