Scientists have produced the first consensus criteria to diagnose chronic traumatic encephalopathy (CTE) in living people.

The state of play: As of now, CTE can only be diagnosed after death. But a new paper, written by over 20 scientists, is a step toward a "biomarker" that could definitively say whether a living person has the disease.

Why it matters: The closer scientists get to being able to detect CTE during life, the closer the existential threat to contact sports, namely football, becomes.

• What happens when an active NFL player finds out he has CTE? Will he retire? What happens when numerous players find out?
• Scariest of all, what if a 15-year-old football player is diagnosed with CTE? Should youth football even continue?

Of note: Flag football is on the rise due to safety concerns around kids starting tackle football too early. But roughly 1.4 million kids ages 6 to 12 still played tackle as of 2018.

The backdrop: The brains of deceased NFL players like Junior Seau and Ken Stabler have been donated to science so CTE could be confirmed, and the results are alarming.

• Eye-opening stat: Ann McKee, a neuropathologist, examined the brains of 111 deceased NFL players. All but one had CTE.
• The NFL has responded by making the game safer through rule changes and equipment upgrades, and America's love affair with football has continued largely unabated.
• 71 of the 100 most-watched broadcasts of 2020 were NFL games, and just last week the league nearly doubled its already massive TV deals.

Between the lines: The exact cause of CTE remains unclear, but we do know that it can be detected at an early age and spread rather quickly.

• Tyler Hilinski, the former Washington State QB who died by suicide, had Stage 1 CTE. He was 20.
• Aaron Hernandez, who killed himself in his prison cell, had Stage 3 CTE, which researchers had never seen in a brain under 46 years old. Hernandez was 27.

The big picture: As scary as CTE is to read about, that's mostly what we've done: read about it. What happens when we see it?

• The reality of this disease has been conveyed mostly through studies and tragic stories told by family members of the deceased.
• What happens when we know people who have it? What happens when we hear them talk about it and see them suffering from it?

The bottom line,via The Nation's Dave Zirin: "The days of plausible deniability — by the NFL, by players, and by fans — will be coming to a screeching halt in the next several years."

TheNational Suicide Prevention Lifeline(1-800-273-8255) provides 24/7, free and confidential support for anyone in distress, in addition to prevention and crisis resources. Also available foronline chat.