Well, if they haven't dreamed yet, it's difficult to say for sure what will happen. I think the best thing is to just not treat them like they're already doomed. They'll need the support, more than anything.
If you dream of flowers and rainbows, it's easy. But most of us don't. A lot of us have to face what happened in those dreams, or memories, or however you want to look at them - and we can't try to better ourselves if people don't give us a chance to.