There are several vitamin and mineral deficiencies that can cause symptoms of depression. If you happen to have one of these deficiencies then a supplement will help you. If your depression is caused by something else then supplements will not be the answer.
B-complex vitamins are essential to mental and emotional well-being. They cannot be stored in our bodies, so we depend entirely on our daily diet to supply them. B vitamins are destroyed by alcohol, refined sugars, nicotine, and caffeine so many people may be deficient in these.