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

Note: Examples of "personal services" are dry cleaning and hairdressing (Data: Wulsin et al.) *

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.

As the authors of this recent study readily admit, this is just a few hundred thousand people in one region, so it's a little iffy to generalize nationally from these numbers. That said, these findings do align roughly with the few studies that have been done on depression rates in specific industries. And one thing for sure is that bus drivers do have it rough around the world: A 2006 paper noted 50 years' worth of studies documenting their plight.

The Industries With the Lowest Rates of Depression

Note: Examples of people in "recreation services" are dance teachers and casting directors (Data: Wulsin et al.)

One interesting thing that can be done with this data is seeing if high-depression industries have any surprisingly similar characteristics. The researchers found that the jobs with the highest rates of depression tended to "require frequent or difficult interactions with the public or clients" and have "low levels of physical activity." Perhaps that explains why miners and highway-construction workers—two physically involved jobs without much outside communication—have the low rates of depression that they do.

Here are some industry-specific rates of depression that are closer to 10.45 percent, the average rate across all industries studied:

Rates of Depression in Other Industries

Wulsin et al.

* This chart originally mislabeled “social services” as “social work.” We regret the error.