Kansas City Chiefs - My Take: Brain Research

Larry Johnson says he believes football damaged his brain.

What science cannot yet tell him is whether he is right.

The former Chiefs running back, now 46, told ESPN that he continues to experience serious short-term memory and orientation problems. Johnson has publicly said for years that he believes he has chronic traumatic encephalopathy, or CTE. A new ESPN report highlighted research seeking something that currently does not exist: a validated method of diagnosing CTE while a person is alive. 6abc Philadelphia

For Chiefs fans who remember Johnson carrying the football seemingly every Sunday in the mid-2000s, the story is uncomfortable.

It should be.

But the most responsible response is not to diagnose him from a distance.

It is to understand why getting a reliable diagnosis someday would matter so much.

Johnson’s Workload Provides Context, Not a Diagnosis

Johnson was one of the NFL’s most heavily used running backs during his peak in Kansas City.

He recorded 457 touches during the 2005 season, and across 2005 and 2006 he handled 752 rushing attempts and caught another 74 passes. Yahoo Sports

It is tempting to draw a straight line from that workload to Johnson’s current concerns.

Medical science does not allow us to do that.

CTE is associated with repeated head impacts, but symptoms such as memory problems, mood changes and difficulty concentrating can occur with many other conditions. Mayo Clinic says CTE still can be definitively diagnosed only through examination of brain tissue after death, and no test for living patients has yet been validated. Mayo Clinic

Johnson’s football history matters.

His reported symptoms matter.

Neither proves he has CTE.

That uncertainty is exactly why the research matters.

A Test Could Do More Than Put a Name on a Problem

Boston University researchers have been studying former football players alongside comparison groups as they search for patterns in brain imaging, blood biomarkers, cognitive testing and other measurements that could eventually identify CTE during life. ESPN’s reporting says researchers have followed more than 300 former players and believe meaningful progress is being made. 6abc Philadelphia

The obvious value of a reliable test would be answers.

But answers could have practical consequences too.

A person experiencing memory problems does not automatically have CTE. Other neurological or psychiatric conditions can produce overlapping symptoms, and some may have treatments or management strategies that differ significantly.

Accurately separating those conditions is far more useful than simply telling every former football player with cognitive problems that football must be the explanation.

That is where diagnostic precision becomes more than an academic issue.

Recent Research Also Warns Against Moving Too Fast

There is another side to the excitement around a possible living CTE test.

Scientists have to be certain it actually identifies the disease.

Researchers at the University of Pennsylvania published findings this year showing that 75% of people who met proposed clinical criteria for traumatic encephalopathy syndrome did not show CTE pathology when their brains were later examined at autopsy. The authors warned that inaccurate diagnosis could carry serious consequences for patients and families. Penn Medicine

That finding does not mean CTE is imaginary.

It means symptoms alone are not specific enough.

That is a crucial distinction.

A diagnostic test that produces false certainty could create a different problem — convincing people they have an irreversible degenerative disease when another explanation may exist.

The goal therefore cannot simply be “a CTE test.”

It has to be a test clinicians can trust.

The Scale of the Question Is Significant

A large 2026 study examined 878 former NFL players who died between 2016 and 2021 and found CTE in at least one-quarter of them. Researchers described that percentage as a conservative estimate but also acknowledged important limitations in the study population and cautioned that the results cannot determine the prevalence of CTE among current players or living retirees. The Washington Post

Those limitations matter.

So does the finding.

The conversation about football and brain health has moved beyond whether repetitive head impacts deserve serious study.

The harder questions now involve individual risk, diagnosis, prevention and eventually treatment.

Those questions become much more useful when doctors can identify what is actually happening in a living patient.

Chiefs Fans Know the Player Behind the Numbers

Johnson’s Chiefs career is remembered for enormous rushing performances and enormous workloads.

His name still brings back images of one of the most physical periods of Chiefs football.

That history makes his current comments difficult to separate emotionally from the player fans watched.

But nostalgia cannot provide a medical answer.

Neither can regret.

The best thing football can offer former players facing these questions is better science, better medical care and honesty about what is known and what remains uncertain.

My Take

Larry Johnson believes he has CTE.

Maybe someday medicine will be able to tell him whether he does.

Right now, it cannot.

That may be the most important part of this story.

Football fans have become much more aware of CTE over the past two decades, but awareness without diagnostic certainty leaves former players in an awful middle ground: they can recognize symptoms, know their history of repeated impacts and still not know what disease — if any — is causing what they are experiencing.

A reliable living test would not undo a single hit Johnson absorbed.

It would not automatically create a cure.

But it could replace speculation with evidence.

For players who spent years giving their bodies to football, that would be meaningful progress.