Happy with the soil

The happiness of working with soil is partly due to the fact that you pick up particularly happy bacteria while digging. University of Colorado researcher Christopher Lowry injected mice with the soil-dwelling bacterium Mycobacterium vaccae and as a result of the study he found increased serotonin levels in the mice's brains.

You can easily get your own dose of the same medicine by taking a walk in the forest or by planting something. You don't even have to wait until spring. For example, why not grow basil in a pot in your sunniest window.