I currently take a multi vitamin, omega 3/6, and one of those vit c + zinc fizzy Berocca things.
Not sure how much good it all does, as I train 4 times a week and try and eat healthily at the same time, but I do know that when I don't / can't train, eat badly, and don't bother with the vitamins, I feel like utter d*gsh*t in comparison.
I'm a firm believer in regular exercise, a good diet and sufficient sleep being the best anti-depressent there is.