Feeling stressed? A bit down? Taking a vacation is more than just a fun diversion from the day-to-day grind. There’s a growing body of scientific evidence that shows travel is very good for your mental health.

In the past decade or so, researchers have learned a lot about why travel makes us happy. Psychologists who study the economics of happiness call it the Easterlin paradox: Money can lead to happiness, but only up to a point — and then we adapt. A 20-year study by Dr. Thomas Gilovich, a Cornell University psychology professor, asked participants to self-report their happiness after making any major material and experiential purchases.

At first, the participants ranked their happiness with both kinds of purchases about the same. But over time, their satisfaction with material things went down, and their satisfaction increased with experiences they had spent money on.