I'm not saying it will work as well as a psych drug, but you might try adding fish oil supplements to your diet. Studies suggest they may help with depression. Be sure to ask for the non-mercury ones, and ones without impurities. You can ask at GNC, for instance, and they should be able to help you.

You can test to make sure you've got good-quality ones, without mercury and whatnot, but taking one of the supplements and poking it with a pin, squeezing out the liquid inside on a China plate or similar (NOT paper), then put it in the freezer for at least five hours, if not overnight. When you pull it out, the liquid should either evaporate or remain a liquid, which will tell you it's high-quality. If it's coagulated or gotten slushy, you don't want it.