This is a very interesting observation. I know a few registered nurses who had to study the placebo effect to earn their degree and I recall that placebos are

This is a very interesting observation. I know a few registered nurses who had to study the placebo effect to earn their degree and I recall that placebos are only effective if the patient has a belief that the treatment would work (and then they are only about 30% effective). following that logic it could be possible that placebo treatments become more effective as more of the population _believes_ that they are effective. You just have to hope that no one pops the placebo-belief bubble for a particular treatment, or people might see that the emperor has no clothes ;)