I think the power of will is very strong on the human body, and some stories are truly extraordinary. It is pretty amazing what our bodies can do, and how a positive outlook can have. Take Michael Douglas and his cancer. He had stage iv cancer which is pretty well the end of the line, but he kept a positive outlook and "beat" it. We know very little about the brain, and I believe a positive outlook can accomplish very great things.
It is a complex effect. Having a positive look on the outcome, seems to speed up the healing process. The how and why are quite a mystery though.