05/04/2009 05:12 am ET Updated Nov 17, 2011

9 Mood-Boosting Tricks Of The Happiness Trade

I've succumbed to full-blown depression just once, and the only good that came of it was learning that I never wanted to experience anything like it again. So I started collecting little mood-boosting tricks--small, helpful ways to pull myself back from the edge. Science is beginning to explain why they actually work, which means that these days I don't feel ridiculous when I'm in my car and someone catches me belting out a Beatles song.

Find out the science behind these mood-boosting tricks!

You rent a bunch of stand-up comedy DVDs.
A smile can improve your mood. In one study, participants view a cartoon while simulating a smile or between puckered lips. The first group found the cartoons funnier.