I though the “placebo effect” is just regression to the mean. I.e. “sick people tend to get better”

It is quite measurably not, oddly - https://www.health.harvard.edu/mental-health/the-power-of-th...

Essentially believing you have been given something that will make you healthier, can reduce the stress responses, pain perception and other issues that may be making the problem worse. In some cases it can be enough to allow the immune system to get better traction and objectively get healthier faster than with no medicine.

Pretty weird eh?

The wild part is that the body releases internal painkillers when they get some fake (or real) ones, and that this reaction can be blocked by naloxone, indicating that it's a physical response.

No, the mind can have a significant effect on the body. For example this webmd article on placebo cites studies where what the participant was told about a pill (stimulant vs sleep aid) effected heart rate, blood pressure and reaction time in opposite directions. https://www.webmd.com/pain-management/what-is-the-placebo-ef...

Nah, it works the other direction too. People expecting side effects from a placebo often get them- though you could argue that many side effects are common symptome now being associated with the drug. Still, the placebo effect beats no treatment per https://ebmh.bmj.com/content/5/1/15 or https://pubmed.ncbi.nlm.nih.gov/12535498/

Only in subjective outcomes. There was no objective outcome where an effect could be perceived.

Interesting, it looks like the studies I was thinking of are fairly old: https://www.scientificamerican.com/article/study-finds-place...

Actually, the studies you cite seem to be in line with this Scientific American article: no objective benefits, but some efficacy on subjective benefits and pain reduction.

It isn't. People recover better with a placebo than with nothing. There are studies that even show that some placebo are better than other based on the price, the colour, who prescribed it, ...

That doesn't seem to be all of it.

See also https://en.m.wikipedia.org/wiki/Nocebo

> Just like the placebo effect causes real, very significant healing effects

No, not really. https://www.painscience.com/articles/placebo-power-hype.php

Edit: gee, apparently I hit a sensitive topic. I did not realize that Hacker News was so attached to a belief in such a strong placebo effect.