I think Love can help fight depression, but it depends on the situation and the love.

So my family, who always loves me no matter what, who has seen me through every depression I've ever experienced....sometimes, most times even, their love has been enough to keep me from acting on any intentions I've had, yet not enough to keep me from feeling the depths of despair.

Only recently, having been thrown into depression first from an unfortunate medication mishap, and then a work situation, did I go through a depression with a partner who didn't leave me....although it wasn't easy...love did help and I think without it I may have ended up much worse off.