The prospect of diagnosing chronic traumatic encephalopathy in living individuals is nearing reality, forcing NFL players to weigh a difficult choice: learn if they have the degenerative brain disease, or remain uncertain.
Former All-Pro running back Larry Johnson, 46, openly discusses his struggles with disorientation and short-term memory loss. He reports not remembering where his car is parked or losing awareness while driving, and believes he has CTE.
Johnson was a first-round pick by the Kansas City Chiefs in 2003 and played nine seasons in the NFL as a physical running back. He attributes his current symptoms to the constant pounding his body endured during his career.
Currently, CTE can only be definitively diagnosed after death through brain examination. Many former NFL players have committed their brains to science to aid post-mortem research.
Michael Alosco, a neuropsychologist and associate professor at Boston University, said scientists are "close" to a live diagnosis. Alosco is part of the government-funded Diagnose CTE Research Project, now in its second phase.
The project's subjects are 50 years and older, as CTE is generally thought to be developed enough for testing at that age. Since 2015, researchers have monitored over 300 former players alongside Alzheimer's patients who did not participate in contact sports, seeking patterns in testing data.
An exact timeline for these research efforts remains unclear. A reliable diagnostic test could change how doctors approach treatment for players experiencing CTE-related symptoms.
Rachel Grashow, a Harvard University researcher, highlighted that many cognitive conditions overlap with CTE symptoms but are treatable. Players who attribute treatable symptoms to CTE face a higher risk of self-harm.
A 2024 study found that nearly one-third of former NFL players experiencing general health issues like sleep apnea, hypertension, low testosterone and depression believed they had CTE. This group was five times more likely to report suicidal thoughts than players who did not link their symptoms to the disease.
ESPN asked over 30 active and retired NFL players about their concerns regarding CTE. Indianapolis Colts tight end Mo Alie-Cox, 32, in his ninth season, said he would not want to know if he had CTE. Alie-Cox cited concerns that people would treat him and perceive him differently if he received a positive diagnosis.
Researchers widely believe repeated sub-concussive head hits cause CTE. The condition has no specific symptoms or treatment, largely because doctors cannot diagnose it while a person is alive.
