Marshawn Kneeland diagnosed with stage 1 CTE after suicide

Researchers at the Boston University CTE Center announced that former Dallas Cowboys defensive end Marshawn Kneeland has been diagnosed with stage 1 chronic traumatic encephalopathy (CTE). Kneeland, who died by suicide in November 2025, was only 24 years old. His family shared the diagnosis to raise awareness about the potential struggles faced by athletes in high-contact sports. Dr. Ann McKee noted that they have found CTE in nearly half of athletes studied who died before age 30. The Cowboys honored Kneeland for the remainder of the 2025 season with commemorative decals and shirts.

• 2:11 PMYahoo Sports — Former Cowboys DE Marshawn Kneeland diagnosed by researchers with stage 1 CTE