There is now overwhelming evidence that nutritional therapy help treat depression. There are alternatives to drug therapy. In fact anti-depressant medications can only treat symptoms not its biochemical causes and in the end may do more harm than good.
For more information on alternative therapies see here
People should also be aware that SINGLE nutrients like St Johns wort, 5-HTP or SAM-e, Fishoil and so on, can not always treat a mental disorders, because mental illness involves a very complex biochemistry, that cannot be tinkered with by simple and single or even multiple nutrients or drugs.
Hit or Miss Supplements for Depression