As medicine comes to understand more about depression and mental illness, we not only develop better chemical anti-depressants, we've begun to learn about the anti-depressants that already exist, all around us. There is a whole medicine cabinet of anti-depressants available to us right on our plates – if we eat the right foods:

Packed with folate, dark leafy greens such as spinach, kale and Swiss chard fight against all kinds of inflammation. What's that got to do with depression? The so-called “neuroinflammatory hypothesis” of major depressive disorder upholds that depression is caused by inflammation in the brain, and the science seems to bear that out. So eat your spinach; not only will it make you strong like Popeye, it may give you his sunny disposition as well.

We've sung the praises of walnuts before, for their effectiveness in keeping colon cancer and prostate cancer in check. Now we want to sell you on their benefits against depression. Studies have demonstrated how omega-3 fatty acids support brain function and reduce depression symptoms, and walnuts are one of the most robust plant-based sources of omega-3 fatty acids.

Another study points to free radicals as culprits. Actually, it points to a low selenium level as the culprit – the young people in the study who were running low on that mineral were more likely to be depressed. And since selenium is the Great Free Radical Slayer, the researchers connected the dots. Brazil Nuts are so loaded with selenium that just one gives you about half of your recommended daily allocation.

Depressed? Drink a glass of milk. The vitamin D for which milk is so well-known is something of a depression eraser. Low serum levels of vitamin D are associated with clinically significant symptoms of depression in otherwise healthy individuals, according to this study.

The antioxidants found in abundance within foods such as berries havebeen found to be an effective combatant against general anxiety disorder and other stress-related ailments. Anti-oxidants actually deactivate free radicals before they can attack cells.

It's quite possible that the anti-depressant drug that your doctor has prescribed for you works simply by targeting the way your brain uses serotonin, the “feel good” hormone. Tryptophan does the same thing, only you won't need a prescription for it: the serotonin-producing chemical is found in turkey.

Several studies have indicated that omega-3 fatty acids are effective in treating depression where no other treatments are effective due to high inflammation levels in the brain. The best sources for these chemicals are fatty fish, such as salmon.