They have to want to help themselves, if they don't there's nothing more you can do. You have to make that decision on when to walk away from it.
What's your opinion when you live with someone who doesn't want to help themselves? They've been to rehab for drug addiction and basically they don't want to change their life. Would you throw the towel in for good?
I think that they need to go and at least try to help themselves. Not saying that you need to throw in the towel or anything, you need to tell that person that they are the one who can change their own life. No one else can do that so they need to help themselves