pikaso commented on dienasgramata's post:

He has a lot of time for the law in Oregon, where doctors can give a terminally ill patient a "potion to take when life gets too bad. I believe something like 40% or more of the patients die without taking it. Which means that every day they're thinking, 'Hmmmm – today's worth living.' And then one day they don't, and they die. That seems to me a very human thing, and a very good thing, because they can think, 'OK, that's sorted, I've got the potion, now I can get on and try and get the most out of life.'"

http://www.guardian.co.uk/books/2010/sep/01/terry-pratchett-alzheimers-assisted-suicide