Marshawn Kneeland Diagnosed With Stage 1 CTE After Dying by Suicide at 24

3 articles · Updated · NBC Sports · Jul 7

Boston University researchers found stage 1 CTE in Marshawn Kneeland’s brain after the former Cowboys defensive lineman died by suicide in November 2025 at age 24.
The diagnosis came from post-mortem brain tissue analysis released by his family through the Concussion & CTE Foundation; CTE still can be confirmed only after death.
Dr. Ann McKee said the finding was not surprising, noting the center has detected CTE in nearly half of studied athletes who died before age 30.
Foundation CEO Chris Nowinski said Kneeland developed CTE despite playing in the era of concussion protocols and improved helmets, arguing repeated head impacts—not just concussions—drive the disease.
Kneeland’s family said the diagnosis offers context for struggles he may have faced and aims to raise awareness of long-term brain-disease risks across contact sports.

Sources

NBC Sports8h ago

Marshawn Kneeland Diagnosed with Stage 1 CTE Posthumously

USA TODAY21h ago

Marshawn Kneeland CTE diagnosis announced, Cowboys DE died by suicide at 24

AtoZ Sports6h ago

Former Cowboys DE Marshawn Kneeland diagnosed with CTE months after his tragic death, here's what we know

13 Sources

If CTE is only confirmed after death, how are today's athletes supposed to manage their neurological health?

With modern safety gear failing to stop CTE, is the future of American football itself in question?

Stage 1 CTE Confirmed in Marshawn Kneeland: A Wake-Up Call for NFL Mental Health and Player Safety

Overview

On July 7, 2026, Marshawn Kneeland, a Dallas Cowboys defensive end, was posthumously diagnosed with Stage 1 Chronic Traumatic Encephalopathy (CTE), bringing new understanding to his long-standing mental health struggles. This diagnosis provided a posthumous explanation for the challenges he faced, which were documented as far back as 2020, including serious concerns for his well-being and incidents that required police and counselor intervention. The confirmation of CTE highlights the deep connection between repeated head trauma and mental health issues, emphasizing the urgent need for better support and awareness for athletes facing similar battles.

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