He added that in today’s television news environment, the definition of breaking news “means the latest thing we have to show you.”

Leslie-Jean Thornton, a journalism professor who is a colleague of Mr. Gillmor’s at Arizona State University, said that even faculty members who by necessity were steeped in news needed breaks from it.

“As journalism professors, there’s a need and a desire to stay on top of things — so much so that it becomes somewhat addictive for some of us,” she wrote in an email. “It’s hard to step away, even for a few hours, but yet the constant wash of uncertainties is emotionally draining and physically harmful — teeth damaged from being clenched in anger or frustration, skyrocketing blood pressure, heart palpitations.”

She added, “I joke that we need trauma care, but I’m not really joking at all.”

Graham C. L. Davey, emeritus professor of psychology at the University of Sussex in England, said in an email that many people followed the news because they did not want to be caught unaware.

“These are the people with an intolerance of uncertainty, and are probably already anxious individuals, and are exactly the ones for whom negative news has a negative psychological impact on their own personal anxieties and worries,” he said.

As consumers become satiated, the news media responds by increasing the “emotionality” of its coverage, meaning negativity is emphasized to keep customers engaged, he wrote.