When doctors test new medicines, they often compare it against another medicine -- or against a placebo. A placebo is a fake; it is known to have no effect other than what is given it by the hope placed in it. There are arguments and counter-arguments about their effectiveness. There are circumstances when a placebo alone won't help. There are other circumstances where a placebo will make some kind of difference.
That is to say, the clinical testing procedure has to take into account that hope alone is measurably good for you, and makes an objective difference in your health and wellbeing.
I'm not advocating placebos, or anything that is fake. I would simply want people to take hope itself seriously. It has proven itself in many clinical trials by now. If unfounded hope can make a measurable difference in someone's life, how much more difference is made by a solid and trustworthy hope.