Grow Some Plants, or At Least, Do Some Digging

The practice
Find a way to do some gardening. Whether it's re-potting your house plants into good new compost, or planting a row of pole-beans alongside your house or on your balcony, gardening is good therapy. You don't have to do anything complicated. Hanging out with plants, enjoying their progress from sprout to leaf to flower to fruit, is satisfying and calming in itself. But actually, it turns out having your hands in the soil is extra good against depression.

The theory
I have always said that I feel better when I can garden, on however modest a scale, but it was only today that I discovered new scientific research that indicates why. The bacterium mycobacterium vaccae, present in soil, apparently increases serotonin in the brain. Serotonin is a neurochemical that seems to be linked to depression--if you don't have enough of it. Mycobacterium vaccae also encourages growth of serotonin receptor cells, which means that it makes it easier for your brain to be positively affected by serotonin, too.

Obviously the scientific data is more complex than I'm making it sound. But the bottom line remains the same--getting your hands in some soil is scientifically proven to be very likely to make you feel better.