At least 1 in 4 deceased NFL players had CTE

Clinical takeaway: Evaluate former contact-sport athletes who develop cognitive or functional symptoms for treatable contributors and consider specialist referral, while explaining that chronic traumatic encephalopathy (CTE) can currently be confirmed only after death.

Repetitive head impacts are associated with neurodegenerative disease, but the prevalence of CTE among former NFL players has been uncertain because diagnosis requires postmortem brain examination.

In this retrospective cohort study, researchers identified 1,712 former NFL players from the hard-shell helmet era who died during 2008-2021. Of the 338 players whose brains were examined, 315 (93.2%) had CTE, placing the possible prevalence among all decedents between 18.5% and 98.7%.

Brain donation was most frequent during 2016-2021, when 235 of 878 deceased players underwent examination and 215 had CTE. Even under the most conservative assumption—that no non-donor had CTE—24.5%, or approximately 1 in 4, of all players who died during this period had the disease.

Dementia was diagnosed in 59.8% of all donors and 61.3% of donors with CTE. Nearly one-third of donors had stage IV CTE; 90.4% of this group had dementia, representing a 44% higher prevalence than among donors without stage IV disease.

The observational findings cannot establish causality or define the true population prevalence because brain donation may have been prompted by symptoms and informant histories were susceptible to recall bias. Lead author Daniel Daneshvar, MD, PhD, nevertheless called the findings “a wake-up call for the NFL and scientific communities.”

Source: Daneshvar DH, et al. (2026 Aug 25) BMJ. Prevalence of chronic traumatic encephalopathy at death in National Football League players: retrospective population based cohort study, 2008-21