Study: At least 1 in 4 Former NFL Players who died between 2016-21 had CTE
Research findings from Mass Brigham General, Boston University and the Concussion & CTE Foundation are a wake-up call for the NFL and scientific communities
In a new study from Mass General Brigham, Boston University, and the Concussion & CTE Foundation, researchers found evidence that at least 1-in-4 former NFL players who died between 2016 and 2021 had CTE at the time of their death.
“Community brain bank studies have shown that CTE affects less than 1% of the general population. To find that somewhere between 24.5% and 97.7% of NFL players from that time period had this progressive brain disease is a wake-up call for the NFL and scientific communities,” said lead author Daniel Daneshvar, MD, PhD, Chair of Physical Medicine and Rehabilitation at Mass General Brigham and Earl P. and Ida S. Charlton Associate Professor at Harvard Medical School. “These data, alongside my experience treating NFL players with dementia in clinic, indicate that we need to dedicate resources towards developing a cure.”
Concussion & CTE Foundation co-founders Dr. Chris Nowinski and Dr. Robert Cantu are among the authors of the study, which was published on August 25, 2026, in BMJ and featured in the New York Times.
What You Need to Know
What this Research Means
How Researchers Figured this Out
Why this Research Matters
What this Research Doesn’t Tell Us
What this Research Means
How Researchers Figured this Out
Why this Research Matters
What this Research Doesn’t Tell Us
What this Research Means
- This study found that at least 1 in 4 former NFL players who died between 2016 and 2021 had CTE at death.
- For comparison, studies of the general population consistently find fewer than 1% of the population has CTE.
How Researchers Figured this Out
- Researchers identified 878 former NFL players who died from 2016-21.
- Of those, 235 players (26.8%) donated their brains for study.
- Among the 235 players whose brains were donated and studied, 215 (91.4%) had CTE at death.
- That means the most conservative estimate is 24.5% of all former NFL players who died in that period had CTE at death.
- The opposite extreme, that nearly every player who did not donate their brain also had CTE, means that up to 97.7% of players in that study period could have had CTE. The true prevalence likely lies somewhere in the middle.
Why this Research Matters
- This study shows that CTE is a serious health issue among former NFL players.
- The odds of developing CTE increase with exposure to repetitive head impacts, so if CTE prevalence is higher than we thought in NFL players, it’s likely also higher than previously believed among former college and high school players.
What this Research Doesn’t Tell Us
- It does not tell us how many living former NFL players have CTE.
- It does not mean that 1 in 4 current NFL players have CTE.
- It does not tell us exactly how CTE prevalence may be changing in younger generations of players.
Reach Out to the HelpLine
If you or a loved one are concerned about symptoms that could be related to CTE, please reach out to our HelpLine today for free, personalized support.
We’ll connect you with trained resource specialists who know what you’re going through and can help you find a path forward.
We’ve also created this downloadable resource that outlines immediate steps you can take if you or a loved one are concerned about CTE.
Participate in Research
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