Lean proteins; Lean proteins, however, carry plenty of amino acids, which may positively affect your mood.

Omega-3 fatty acids; people with higher levels of omega-3 fatty acids were less likely to experience moderate or mild symptoms of depression. Sources that contain the highest levels of omega-3 fatty acids include flax seeds, walnuts, and salmon.

Berries; berries may help prevent the release of cortisol, a hormone produced by the adrenal gland.Keep berries in your bag to combat stress when it hits.

Folic acid; You can get high amounts of folic acid in leafy greens, oatmeal, sunflower seeds, oranges, fortified cereals, lentils, black-eyed peas, and soybeans.

Vitamin B-12; Food sources of vitamin B-12 include lean beef, clams, oysters, crab, wild salmon, eggs, cottage cheese, yogurt, milk, and fortified cereals.

Vitamin D; Food sources of vitamin D include milk, egg yolks, mushrooms, and fish that have bones. You can also get vitamin D in supplement form.

Dark chocolate; Participants in one study were given a dark chocolate mixed drink every day for a month. Results showed significantly improved mood, which researchers linked with a high polyphenol content. Polyphenols are a type of antioxidant.

Turkey contains the amino acid tryptophan and melatonin, which are the calming and relaxing chemicals that make you tired after Thanksgiving dinner.

Magnesium, also found in bananas, may improve sleep and reduce anxiety — two symptoms of seasonal depression.