To make matters worse, the payoff for all that stress may be wanting: A 2014 report found that nearly 40 percent of the doctoral students surveyed hadn’t secured a job at the time of graduation. What’s more, roughly 13 percent of Ph.D. recipients graduate with more than $70,000 in education-related debt, though in the humanities the percentage is about twice that. And for those who do secure an academic post, census data suggest that close to a third of part-time university faculty—many of whom are graduate students—live near or below the poverty line.

A new study by a team of Harvard-affiliated researchers highlights one of the consequences of these realities: Graduate students are disproportionately likely to struggle with mental-health issues. The researchers surveyed roughly 500 economics Ph.D. candidates at eight elite universities, and found that 18 percent of them experienced moderate or severe symptoms of depression and anxiety. That’s more than three times the national average, according to the study. Roughly one in 10 students in the Harvard survey also reported having suicidal thoughts on at least several days within the prior two weeks. (Other recent studies have had similar findings, including one published earlier this year that described graduate-student mental health as a “crisis.”)