If someone is going to be a vegetable for life I say they might as well be offed. Who would WANT to be kept alive as a vegetable?
For the suicide thing, maybe it was just me, but I tended to sleep... a lot. Like 16 hours a day when I was depressed, sometimes more. Anything to make time pass as fast as it could. I would state that as a symptom. (I may have missed it reading through, but I don't recall seeing it)