A double-blind double-cross if you will.

the study is setup so that the person taking the pill and the person giving it to the participant who is recording the results both don't know whether the pill is a placebo, but some other person knows or it's written somewhere else what the person got so in the end they can know if the result was from placebo. the important part is the researcher at the time of recording/interpreting doesn't know, because if they know they may be bias in favor or against the placebo.

The people interacting with patients don't know which is which, but somebody does.

The whole point is seeing if the drug is better than a placebo, so you definitely need that information when it's time to analyze data.

deeply meaningless rant:

why do we need two words for placebo effect when it's just positive placebo and negative placebo, i know i know, the word placebo has an ingrained positive aspect in its root... but it's not like the english language ever gives a fuck about the roots of a word, it bastardises all words equally! why make an exception now?? why not just call it negative placebo!

Placebo Blocker

People can be idiots for forming a firm belief that something can be bad for them when all evidence and expert opinion contradicts it.

Anybody, idiot or otherwise can, due to the nocebo effect, trully feel bad due to nothing else than a strongly held belif that something will make them feel bad.

Those are two separate things.

There aren't indications of idiocy from feeling actual effects due to nothing else than a placebo or nocebo effect from a strongly held belief, whilst there can be idiocy in the way one gains a belief so strong was that it actually triggers one of those effects.

The example given by the previous poster does seem to fit a situation of people who are indeed idiots not because of how they feel but because of how they came to believe they would be feeling like that in a certain situation.