Hi,
After being depressed for years, i found that fish oil supplements helped me a lot. I don't take them anymore and don't have a problem anymore, but i would do it again.
My daughter had a bit of a depression when she was about 10... i'm sad to say there is no doubt in my mind that she learned depression-type behavior from me. Anyway, i gave her cod liver oil every day for a few months and it helped her too.
(i can't believe the stuff i admit on this site)

I have also definitely found that a regular exercise routine is very uplifting.