The placebo effect only really changes self-reported symptoms. It makes people feel much better and that shouldn't be discounted, but it doesn't change things you can make objective measurements of - like whether the patient is alive or dead.
That isn't actually true. Ask any doctor about patients who just lost the will to live. Also read about the research about morphine and placebos, how a morphine blocking drug actually blocked the placebo effect - without the person knowing they got the blocker drug!
