I wish they had included a third group which received a placebo and was told it was real medicine. The study's not properly complete without one.
I'm not particularly surprised by the results, but I'd be very surprised if the people who knowingly take a placebo do as well as the people who take a placebo believing it's real medicine.
I wish they had included a third group which received a placebo and was told it was real medicine.
That's pretty much what I meant by "... third group who received a placebo that they didn't know was a placebo".
Placebo Effect Benefits Patients Even When They Knowingly Take a Fake Pill
This is a little bit disturbing. (A kind of belief in belief, perhaps? Like, "I know a placebo is where you take a fake pill but it makes you feel better anyway if you believe it's real medicine, so I'd better believe this is real medicine!")
Though it's too bad they (apparently) didn't have a third group who received a placebo that they didn't know was a placebo, to compare the effect size.
Edit: Here's the actual study. RolfAndreassen points out that its results may not actually be strong evidence for what is being claimed.