The family of former Dallas Cowboys defensive end Marshawn Kneeland has shared that researchers found he had Stage 1 chronic traumatic encephalopathy, or CTE, following an examination of his brain after his death.
The diagnosis was made by specialists at the Boston University CTE Center, adding another case to the growing body of research into the long-term effects of repeated head impacts in football. Kneeland died by suicide in November 2025 at the age of 24.
According to his family, the decision to release the findings was driven by a desire to increase public awareness of brain injuries, athlete mental health, and the importance of continued scientific research. They expressed hope that sharing his story could help others and encourage greater understanding of the challenges many athletes may face.
Medical experts note that CTE is a degenerative brain disease associated with repeated blows to the head and can only be definitively diagnosed after death. Researchers also stress that while the condition has been linked to symptoms including depression, impulsivity, and mood changes, it is not possible to conclude that CTE alone caused Kneeland’s death.
Kneeland entered the NFL after being selected by the Cowboys in the second round of the 2024 NFL Draft following a successful college career at Western Michigan. His promising professional career was cut tragically short, and his family hopes his legacy will contribute to advancing research into brain health while encouraging compassion and support for athletes dealing with mental health challenges.
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