When researchers try to determine the types of workers who are most prone to depression, the focus is usually on the misery of those at the bottom of a company’s hierarchy—the presumed stressors being the menial duties they're tasked with and their lack of say in defining the scope of their jobs.

But it turns out that middle managers have it worse. In a new study from researchers at Columbia University, of nearly 22,000 full-time workers (from a dataset from the National Epidemiological Survey on Alcohol and Related Conditions), they saw that 18 percent of supervisors and managers reported symptoms of depression. For blue-collar workers, that figure was 12 percent, and for owners and executives, it was only 11 percent.

The researchers had a hunch about the woes of middle management because it occupies what they call a “contradictory-class location”: Middle managers have higher wages and more autonomy than the workers they manage, but they earn less than their superiors and don’t get to make big decisions. Middle managers often have to enforce strategic policies from the top—ones they didn’t develop—on subordinates who might object to those new policies. Basically, middle managers have the stressful task of absorbing the discontent of both sides.

“Employees in the middle have dual roles that embody aspects of ownership and front-line labor, without the full benefits of being one or the other—they get flak from above and below,” says Seth Prins, a doctoral student in Epidemiology at Columbia University’s Mailman School of Public Health and the lead author of the study. “Unlike standard approaches, which would predict less depression and less anxiety for every rung up the income or education ladder, the idea of contradictory-class location led us to our hypothesis about more depression and anxiety in the middle,” says Prins.