Is there anything short of a near death experience that you think would work? What did the near death experience teach you? I wonder if there is anyway to duplicate the effect without nearly dying?
It put everything into perspective for me, simply being alive gives me a chance at anything, when you have something you take for granted taken away from you, you start to appreciate everything more. Just waking up and seeing the sun was amazing, drinking coffee, going for a walk despite having nothing else - no job, friends or prospects no longer bothered me.
Obviously the high of having your life back doesn't last forever, but the appreciation for everything still lasts, I don't compare myself to others so much anymore and therefore don't feel worthless or depressed.
I don't know how you could simulate this feeling exactly but I would imagine being sent to boot camp would have the same effect. I read a story a while ago that there were these military style disciplinary camps that parents send their spoiled out of control kids to, their beliefs and world views get rattled so hard they come back as angels who appreciate simple things like comfort and not suffering.
That being said, I don't know how a depressed person who react to being in a survival environment, I'm not suggesting it but just thinking of an idea with similar concepts!