How Common Is CTE in Former NFL Players?

Chronic traumatic encephalopathy (CTE), a neurodegenerative disease caused by repetitive head impacts, can be definitively diagnosed only after death. As a result, we have a limited understanding of how prevalent CTE is among professional American football players and whether its severity correlates with dementia risk (Figure 1).

Researchers conducted a retrospective cohort study of all 1712 former NFL players who played in the era of hard-shell helmets and died between 2008 and 2021; 20% had donated their brains for neuropathologic evaluation.