Are you feeling down or depressed? It is a known fact that depression increases in the winter time. So if the darker dreary days or Fall and Winter 'get to you,' increase your intake of complex carbs. Eat more whole grains, fruits, vegetables, and legumes. Yes, these are carbohydrate foods but they are the complex (or good) carbs. These carbs boost your serotonin levels. Serotonin is a mood-elevating chemical in the brain. By the way, these are good foods you should be eating anyway.