WHEN you mull over the differences between states that vote for Republicans in presidential elections and states that vote for Democrats, what do you think about? Perhaps religion: People in red states are far more likely to believe in God. Or maybe media consumption: More people in blue states like NPR.

No surprise there. But there is a little-known difference between blue states and red states that is even more pronounced and perhaps more revealing, too, because it has major public health implications. Blue states are far more likely to use therapy to treat mental illness.

We do not have perfect data on therapy rates by state, but Google searches can give us a pretty good idea. In blue states, there are 54 percent more Google searches for psychotherapists — a broad category that includes searches like “find a therapist,” “counseling” and “cognitive therapy” — than there are in red states. We know that these results are not driven by population size or Internet use because Google data is normalized by total Google searches. According to my analysis of data from the Bureau of Labor Statistics, there are also 76 percent more psychologists or psychiatrists per capita in blue states.

Whatever stereotypes you might have, it is not true that people in blue states are more neurotic or depressed. People in red states and blue states are, roughly speaking, equally likely to take antidepressants.