The Power of the Placebo Effect works even without deception. :)

[kneeproblemguy]

That is cool kind of is it not. If it is true? How does one find out. Clever set up of tests.

PLoS ONE: Placebos without Deception: A Randomized Controlled Trial in Irritable Bowel Syndrome

Placebos without Deception: A Randomized Controlled Trial in Irritable Bowel Syndrome

Them claim that it is "A Randomized Controlled Trial" that sounds rather good then. I mean what can go wrong there?

So Placebo Effect is a thing to reckon with. To take into consideration. But it also allow a lot a deception.

And the dreaded Nocebo Effect Nocebo - Wikipedia, the free encyclopedia

In medicine, a nocebo reaction or response refers to harmful, unpleasant, or undesirable effects a subject manifests after receiving an inert dummy drug or placebo. Nocebo responses are not chemically generated and are due only to the subject's pessimistic belief and expectation that the inert drug will produce negative consequences.

In these cases, there is no "real" drug involved, but the actual negative consequences of the administration of the inert drug, which may be physiological, behavioural, emotional, and/or cognitive, are nonetheless real.

I mean listen to what them say. The Nocebo Effect "are due only to the subject's pessimistic belief and expectation that the inert drug will produce negative consequences.

In these cases, there is no "real" drug involved, but the actual negative consequences of the administration of the inert drug, which may be physiological, behavioural, emotional, and/or cognitive, are nonetheless real."

So if one are a pessimist then even the most positive Placebo Effect can go badly wrong or even worse
there is even a saying for it named Murphy's Law: "Anything that can go wrong will go wrong" or "If something can go wrong then it will go wrong in the most unfortunate and daring circumstances and when you least expect that to happen to you or somebody you care for."