Sometimes when I observe someone doing their job, I can't help but think, "Man, that must be hard." Maybe it's a retail worker dutifully leading a customer to the linens aisle for the umpteenth time. Maybe it's a cab driver who's shuttling passengers around at 5 a.m. It's always hard to say who truly has it harder; perhaps that retail worker and that cab driver have themselves come away from other interactions thinking the same thing I did.

Now, some psychiatrists have spoken on which jobs are actually more of a grind, at least from the standpoint of mental health. A study published last month in the journal Social Psychiatry and Psychiatric Epistemology suggests that some jobs have much higher rates of depression than others.

Using data representing about 214,000 western Pennsylvanians, the study's authors calculated the incidence of depression across 55 industries. The highest rate of depression (16.2 percent) was found among bus drivers. The lowest (6.9 percent) was found among those in "amusement and recreation services," a broadly defined group that includes the sports, fitness, and performing-arts industries.

The Industries With the Highest Rates of Depression

From an economic standpoint, it's important to identify rates of depression because of how much productivity is lost to mental-health concerns (to say nothing of the awful psychic toll exacted on the level of the individual.) One study found that depression costs the economy $83 billion annually, the majority of which is lost because of decreased productivity in the workplace.