John Branch

The actual prevalence, researchers said, may be much higher.

Researchers say it’s all about reducing the total number of blows to the head.

“We never see things that are this dire,” a former chief scientist of the agency said about rates of C.T.E. in former players.

At least one in four N.F.L. players, and likely a much higher percentage, had the brain disease when they died. Will anything change?

The report was commissioned by Blackbird Mountain Guides, which was in charge of the trip near Lake Tahoe in February.

As an executive with the outdoor-supply retailer REI and an experienced climber, he conquered Mount Everest in 1963, when fewer than 10 people were known to have done so.

For decades, there had been an average of 30 each year. With a new deterrent in place, there were none in the second half of 2025.

An acclaimed researcher is an expert at explaining complicated problems. Now she has to confront the most vexing question: What is happening to her?

With dams removed from the Klamath River, a group of Indigenous youth is on a journey to descend the full length, through Oregon and California.

M.I.T. Class President Barred From Graduation Ceremony After Pro-Palestinian Speech (Published 2025)