Over the last decade, anxiety has overtaken depression as the most common reason college students seek counseling services. In its annual survey of students, the American College Health Association found a significant increase—to 62 percent in 2016 from 50 percent in 2011—of undergraduates reporting "overwhelming anxiety" in the previous year. Surveys that look at symptoms related to anxiety are also telling. In 1985, the Higher Education Research Institute at U.C.L.A. began asking incoming college freshmen if they "felt overwhelmed by all I had to do" during the previous year. In 1985, 18 percent said they did. By 2010, that number had increased to 29 percent. Last year, it surged to 41 percent.

For many of these young people, the biggest single stressor is that they "never get to the point where they can say, 'I've done enough, and now I can stop,'" [one expert] says. "There's always one more activity, one more A.P. class, one more thing to do in order to get into a top college. Kids have a sense that they're not measuring up. The pressure is relentless and getting worse."