Eating a diet rich in certain foods are good for depression. I've suffered with depression since I was a child (I'm 42 years old now), so often on the look out for treatments!
A carbohydrate rich diet such as pasta, wholemeal bread, high fibre cereals etc may help. Also Tryptophan is an essential amino acid which is converted in our bodies into serotonin, a neurotransmitter, or chemical in the brain. Foods rich in tryptophan are chicken and turkey, tuna and salmon, beans and seeds.