The brain disease has most commonly been found in athletes in contact sports and others with a history of repeated brain trauma.

Meiko Locksley, one of 152 athletes diagnosed with CTE before even reaching the age of 30 as part of the Boston University CTE Center’s 2023 study, never made it past college football and began exhibiting signs of the disease in his 20s.

The man who killed four people in the New York City skyscraper that is home to NFL headquarters carried a note blaming the league for his mental health problems.