Antidepressant drugs cost Americans $10 billion each year and have many nasty side effects: sleep disturbances, nausea, tremors, changes in body weight. Is there an easier way? According to Time Magazine, one psychologist thinks that exercise may be the best way to treat depression.

Jasper Smits’ ideas aren’t groundbreaking; observational studies in the 1970s and 80s showed that Americans who exercised were not only less likely to be depressed than those who did not but also less likely to become depressed in the future. And in 1999, a Duke study found that aerobic exercise was just as helpful in treating depression as Zoloft. More studies had similar findings: exercise boosts mood.

“I was really surprised that more people weren’t working in this area when I got into it,” says Smits, an associate professor of psychology at Southern Methodist University.

Why does it work? Exercise may alter brain chemistry in much the same way that antidepressant drugs do — regulating the key neurotransmitters serotonin and norepinephrine. A University of Georgia study found that exercise can switch on certain genes that increase the brain’s level of galanin, a peptide neurotransmitter that appears to tone down the body’s stress response by regulating another brain chemical, norepinephrine. As a result, new problems don’t stress us out as much.

Maybe the science behind these findings is just more evidence that we’re not meant to be sitting around all day. Try to move a little more at work or check out these cool new folding bikes. Squeezing just a half hour of cardio into your day might be the key to happiness!

Photo: Kirklees