Health

HuckleB

(35,773 posts) Sun Jul 8, 2012, 11:56 AM Jul 2012

Placebo effects without deception? Well, not exactly…

http://www.sciencebasedmedicine.org/index.php/placebo-effects-without-deception-well-not-exactly/

"...

In other words, not only did Kaptchuk et al deceive their subjects to trigger placebo effects, whether they realize or will admit that that’s what they did or not, but they might very well have specifically attracted patients more prone to believing in the power of “mind-body” interactions. Yes, patients were informed that they were receiving a placebo, but it must be emphasized again and again that that knowledge was tainted by what the investigators also told them about what the placebo pills could do. After all, investigators told subjects in the placebo group that science says that the placebo pills they would take were capable of activating some sort of woo-ful “mind-body” healing process.

In fact, I would say that what Kaptchuk et al did was no different than what we know about what is required to induce placebo effects. They were also far more suggestive than the explanations that investigators conducting placebo-controlled clinical trials offer subjects during the recruitment process. Consider: In most clinical trials, investigators tell subjects that they will be randomized to receive either the medicine being tested or a sugar pill (i.e., placebo). This, patients are told, means that they have a 50-50 chance of getting a real medicine and a 50-50 chance of receiving the placebo. In explaining this, investigators in general make no claim that that the placebo pill has any effect whatsoever. In fact, in most clinical trials, subjects are explicitly told that it does not. In contrast, Kaptchuk et al explicitly tried to “optimize the placebo response” for purposes of the study by telling their subjects that the sugar pill activated some sort of mind-body response that would make them feel better — but only if they religiously took the sugar pills. Yes, they did tell the subjects that they didn’t have to believe in mind-body interactions to experience the healing response. But did it matter? I doubt it, because people with authority, whom patients tend to believe (namely doctors) also told subjects that there was strong evidence showing that these placebo pills activated some sort of powerful “mind-body” mechanism. This alone makes proclamations about how the investigators triggered placebo effects without deception — shall we say? — not exactly in line with the reality of the situation. A far better design would have included at least one more group, namely a group receiving the placebo but without all the suggestion about how it would activate “powerful mind-body” effects using a neutral script that simply said it was a sugar pill and wasn’t expected to do anything. Lacking that additional group, this study tells us very little that we didn’t already know.

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It's worth reading the full thing, IMO.