When Football and Families Collide: What a New CTE Study Shows

A large retrospective study published in The BMJ has sharpened estimates of how often chronic traumatic encephalopathy (CTE) is found at death among former National Football League players. The research team, made up of investigators from Mass General Brigham, Boston University, and the Concussion & CTE Foundation, identified 878 former players who died between 2016 and 2021; 235 of those individuals donated their brains for research and 215 of the donated brains were diagnosed with CTE, producing a conservative prevalence of 24.5% and a theoretical upper bound of 97.7% if every non-donor also had the disease.

When the window is widened to include deaths from 2008 through 2021, 1,712 decedents were identified and 338 brains were examined, of which 315 were found to have CTE, reinforcing that the burden of disease in this population can be substantial. Among brain donors, 104 (30.8%) had stage IV CTE, 202 (59.8%) were judged by study clinicians to have dementia before death, and the presence of stage IV pathology was associated with a 44% higher prevalence of clinician‑diagnosed dementia, a finding that links advanced neuropathology to cognitive decline.

Because CTE is confirmed only after death, families must make choices with incomplete information, and some parents have rethought whether children should play tackle football while others balance sport and community values. Researchers plan further analyses to estimate overall prevalence and to develop ways to identify CTE during life, and continued study of biomarkers, imaging, and exposure measures will be needed before definitive answers can be reached.