Ach ano, co uz je to nejaky systematic review proti vahe slova HPI :). Len skoda ze si ani neklikol na to com som nalinkoval.

Bolest nie je ochorenie. Ano, placebo je proti bolesti statisticky vyznamne efektivne, nasiel by si to aj v tom linku, keby si si ho precital. A proti nicomu inemu:

Binary Outcomes
As compared with no treatment, placebo did not have a significant effect on binary outcomes .

Continuous Outcomes
... there was a beneficial effect of placebo... There was significant heterogeneity among the trials with continuous outcomes. The magnitude of the effect of placebo decreased with increasing sample size, indicating a possible bias related to the effects of small trials.
Pain, obesity, asthma, hypertension, insomnia, and anxiety were each investigated in at least three independent trials. Only the 27 trials involving the treatment of pain (including a total of 1602 patients) showed a significant effect of placebo as compared with no treatment. There was no significant effect of placebo on the other conditions, although the confidence intervals were wide.

DISCUSSION
We did not detect a significant effect of placebo as compared with no treatment in pooled data from trials with subjective or objective binary or continuous objective outcomes. We did, however, find a significant difference between placebo and no treatment in trials with continuous subjective outcomes and in trials involving the treatment of pain. ... The use of placebo outside the aegis of a controlled, properly designed clinical trial cannot be recommended.