http://www.helpguide.org/articles/depression/dealing-with-depression.htm
What you eat has a direct impact on the way you feel. Reduce your intake of foods that can adversely affect your brain and mood, such as caffeine, alcohol, trans fats, and foods with high levels of chemical preservatives or hormones (such as certain meats).
Don’t skip meals. Going too long between meals can make you feel irritable and tired, so aim to eat something at least every three to four hours.
Minimize sugar and refined carbs. You may crave sugary snacks, baked goods, or comfort foods such as pasta or French fries, but these “feel-good” foods quickly lead to a crash in mood and energy. Aim to cut out as much of these foods as possible.
Boost your B vitamins. Deficiencies in B vitamins such as folic acid and B-12 can trigger depression. To get more, take a B-complex vitamin supplement or eat more citrus fruit, leafy greens, beans, chicken, and eggs.
Omega-3 fatty acids play an essential role in stabilizing mood
Foods rich in certain omega-3 fats called EPA and DHA can give your mood a big boost. The best sources are fatty fish such as salmon, herring, mackerel, anchovies, sardines, tuna, and some cold-water fish oil supplements. Aim for two servings a week.