No not evening primrose oil but I've heard a lot about St Johns Wort. Now before you get some read your medication because many say NOT to mix it with anti depressants and why would that be?
Anyway I found it didnt do anything for me - and honestly the way they make those synthetic pills is enough to make me sick
Anyway and its outside the realms of medicine its naturopathy and I think there is another forum for that I personally think the seriously depressed need a bit more than "cure all" medicines and vitamins that as my doctor once told me just makes expensive urine.
I've also read that it is good for treating depression, but the fact sheets issued by the U.S. National Library of Medicine, however, don't list that
as being helpful for.
http://www.nlm.nih.gov/medlineplus/druginfo/natural/1006.html
Best wishes!