Keeping tabs on the things you feel lucky to have in your life is a great way to boost your mood.

In a recent study from psychologists at UC Davis, researchers had 3 groups of volunteers keep weekly journals focused on a single topic. While one group wrote about major events that had happened that week, the second group wrote about hassles they'd experienced, and the last group wrote about things they were grateful for.

Ten weeks later, those in the gratitude-journal group reported feeling more optimistic and more satisfied with their lives than those in any of the other groups and reported fewer physical symptoms of discomfort, from runny noses to headaches.