[medlyyy]

I think you're misunderstanding what "placebo effect" means. Colloquially it's applied to things that "do nothing," or have only a psychological impact but in reality the placebo effect continues to work even when people are fully aware that what they are taking is a placebo:

1. https://onlinelibrary.wiley.com/doi/full/10.1111/jebm.12251 2. https://www.sciencedirect.com/science/article/pii/S152659001...

So the situation is more complicated than "figment of your imagination" or "wishing it away" (this doesn't work and isn't what placebo is referring to by they way - you have to actually receive a treatment even if that treatment has no direct effect) - it's clearly a real biological effect. Just the mechanisms are more obscure.

There's obviously a limit to what placebo effects can accomplish even if they can be positive, and I think the goal & point made is that because surgery is inherently risky, there should be an expectation of benefit over and above what can be accomplished with risk-free methods; ie., that surgeries which are shown to be only as effective as placebo should probably not be performed.

[fooblat]

I find those studies problematic. In the ones I read from your links, the doctor says something along the lines of "this pill is a placebo. It means it has no active ingredients. However, the 'placebo effect' is known to be powerful and if you take these pills as instructed they can still help you..."

As I understand it, a big part of the placebo effect is setting the expectation that the treatment will help. And it is only known to help in subjective conditions, such as pain.

I expect we might see different results if the doctor said something more like "This pill has no active ingredients and does nothing. We are giving it to you to see if you will imagine that it worked anyway."

Kissing a child's scraped knee is not a treatment but, it along with a reassuring "there, all better!" works wonders for the child anyway. They are comforted and relived.

[tsimionescu]

There is as yet no reason to think placebo is a 'real' effect, except for cases of subjective symptoms or body functions under conscious control (directly like breathing rhythm or indirectly like pulse).

For all other cases, like infections or tumors, the placebo effect seems to only be a measure of poorly understood differences in natural processes, which can cause spontaneous remissions at unpredictable rates.

The act of giving fake medicine to the control group has no direct effect on the people taking it - the idealized study results would almost certainly be the same if the control group received no medication at all. However, the reported data would be much harder to trust, as it would be obvious for the data collectors and pacients which group they are part of, making it trivial for them to misreport data and symptoms to influence the result in the direction they desire (whether consciously or not).

That is the real reason for the double blind study design in most tteatments - fear of fake data, not any mysterious healing/detrimental effects from the act of taking sugar pills.