That is incorrect. Evidence suggests that the placebos can be effective even when the subject is aware that they are receiving a placebo. See Placebos without deception.
You cannot legitimately rule out the placebo effect simply because you were aware of the possibility of the placebo effect.
Since I have to go and do a 12 hour graveyard shift, I'll make a quick point on this now and comment on the rest later.
This study presented in the link is the same study ac500 previously provided me on a pm, just in a different presentation (ac500, please confirm this).
Now, for the purpose of my statement with Placebo, I realize that the definition or criteria needs to be refined. But before I do so, a few comments on the study.
A. It's extremely flawed. IBS being the main protagonist of symptoms. Why are the subjects comprised of 70% women and the rest men. Why isn't their other mental conditions, if at all, are not presented or discussed. Was there a blind test, a double blind and mix test conducted? No, there was not. But, as many as these flaws exist, which clearly factor into results and make them unreliable. The grossest and I MEAN GROSSED error and misleading statement in this study, is that it's a Placebo without deception or as such. There is a deception at play in this study, a while it's a minor one, it's is a deception. Note that for ANY placebo to work, may that be an artifact or a sugar pill, a suggestion that 'this will help you', or 'improve your condition', or 'shown to have improved same conditions previuosly' has to be either made or somehow expressed or communicated to the subject. That's the bottom line of Placebo, this is how it works. In this case, while the subjects were told that they will be given Placebos, they were also informed that those Placebos HAVE PREVIOUSLY "been shown in clinical studies to produce significant improvement in IBS symptoms through mind-body self-healing processes" <---- This right there, is classic Placebo at it's best. Not only it's a deception, it's one in the worst kind. They're pulling this stunt literally over the subjects eyes. This is not a Placebo without deception, rather either some twisted reverse psychology or mind games. And the proof for this is that while those subjects shown improvement while using this 'Placebos', they only did so because they were told and suggested that those Placebos have clinically proven to improve IBS symptoms. But guess what, if those patients would have been told that these placebos have no effects whats or ever, or worse, been clinically proven to worsen the IBS conditions, what do you suppose the study results would have shown and proven?
The above is not more and no less analogous to superstition in its mildest form. Think of sports athletes, and I mean the Pros. Ever heard of a Rabbit's foot? A lucky charm, a necklace, a specific sock or shirt or pants or underwear players wear for major games ?? Is that real? Is that Placebo? Is that Superstition? Clearly, those players are aware that this is in their minds... yet, having those artifacts on gives them peace of mind and allows them to perform better... Is that Placebo or superstition? And for that matter, where does religion factor into this? Faith, belief, superstition.. Placebo?
Trust me, you don't want to head there, it's endless.
So let me just refine the definition of Placebo here so there are no mistakes. If a person is already subjected to an ongoing Placebo, and is showing positive correlation and reaction to hypothesized results... without him being aware of it FIRSTLY (although somehow suggested, either flat out or covertly that 'this will improve something'), then any subsequent administering of the drug or the placebo artifact would still work or be active along those parameters. Even if you inform the subject that he was under placebo, unless this person has an iron will power, which is rare, he will still exhibit positive reaction to the Placebo effect. Simply because his mind has already converted to believe that this works. But it's still by deception initially. However, this won't work the other way around.