Depression is an inflammatory disease; where does inflammation come from? [pdf]
  Omega-3 fatty acids, which are important components of
  many healthy foods, such as seafood, nuts, legumes and
  leafy green vegetables, act to reduce inflammation

Score another point for fish oil supplementation, on top of the already enormous pile of scientific research showing it to be a miracle chemical (and I definitely don't say that lightly) [2]. Seriously, if you aren't getting enough omega 3 fatty acids, either from regularly eating lots of fatty fish or through supplementation, you're seriously missing out on some good stuff. Among supplement enthusiasts, it's consistently declared to be one of the only supplements that's actually useful. I prefer the liquid form [1].[1] http://www.amazon.com/Now-Foods-Omega-Lemon-Flavor/dp/B001B4...[2] http://examine.com/supplements/Fish+Oil/Edit: added [2], a well-written examine.com page summarizing fish oil effects