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The Placebo Effect

Roboramma said:
Because when we use placebo controls, they are one of the things that's being controlled for.
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The control is being controlled for? :confused:

Roboramma said:
We also know that the effect "people experience social pressure to say the medicine makes them feel better" is a real effect that can be controlled for (we control for it using placebos), that doesn't mean it's not part of the placebo effect.

Every aspect of the placebo effect can at least potentially be known and controlled for. Why would that make them not placebo?
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You're confusing me. Now you're saying there's no placebo effect because everything can be controlled for.
 
Roboramma said:
Arth said:
The fact that we can potentially track down the different aspects of placebo doesn't make them not placebo.
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Why would they be? If they are known and can be controlled for, why are they still placebo? That doesn't make sense.
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Because when we use placebo controls, they are one of the things that's being controlled for.
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"They" are the actual effects we're talking about. We control for those effects in placebo controlled trials. The reason we give people placebos is to control for a variety of effects. To the extent that an actual physiological mechanism exists, that will be one of the effects that's being controlled for.
 
arthwollipot said:
You're confusing me. Now you're saying there's no placebo effect because everything can be controlled for.
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Maybe that's the implication of your weird definition of placebo, but it's clearly not the implication of my view.

One more time: We do placebo controlled trials for a reason. The reason is to control for a variety of effects. Every one of those effects is a part of the placebo effect. The fact that we understand some of those things doesn't make them not a part of the placebo effect.

We understand for instance that sometimes people taking medication expect to feel better, and thus are more alert to improvements in their condition so are more likely to report positive improvements than those receiving no treatment. That's part of the placebo effect. The fact that we understand the mechanism doesn't make it not part of the placebo effect. The fact that we can control for it by giving people sugar pills doesn't make it not part of the placebo effect.
 
Roboramma said:
But to be clear, when you say that the placebo effect is a sham, you aren't saying that such effects don't exist?
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To be clear, I'm saying, and always have been saying since the very first post in the thread, that the so-called "Powerful Placebo" effect - the "mind over matter" effect that Kapchuk and others promote - is a sham.

In the most recent set of conversations I have been saying that the media claiming that we now understand and can control the placebo effect is wrong. One potential mechanism of placebo has been identified. That doesn't explain the whole placebo effect.
 
Roboramma said:
We understand for instance that sometimes people taking medication expect to feel better, and thus are more alert to improvements in their condition so are more likely to report positive improvements than those receiving no treatment. That's part of the placebo effect. The fact that we understand the mechanism doesn't make it not part of the placebo effect. The fact that we can control for it by giving people sugar pills doesn't make it not part of the placebo effect.
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If you control for, say, regression to the mean in your clinical trial, then regression to the mean no longer contributes to the placebo effect in that trial. That doesn't mean that it is never a placebo factor, but it does mean that it doesn't count towards the placebo effect in your trial. That's why controls exist - to eliminate factors that could otherwise contribute to a placebo effect in your trial.

Is this a clearer way of putting it?
 
arthwollipot said:
If they are known and can be controlled for, why are they still placebo? That doesn't make sense.
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You're very confused. Placebo effects are precisely what placebo-controlled trials control. Whether we know the mechanism of the effect or not is irrelevant.
 
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jt512 said:
You're very confused. Placebo effects are precisely what placebo-controlled trials are designed to control. Whether we know the mechanism of the effect or not is irrelevant.
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Which is why I say that the mouse study shouldn't be considered as addressing the placebo effect at all.
 
arthwollipot said:
I'm a bit confused as to why when something is known and controlled, it somehow is still part of a placebo effect. The placebo effect is defined as all of the responses that are not controlled for.
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This appears to be the source of your confusion. Your definition of placebo effect is wrong. The placebo effect is all responses that are not due to the active treatment. Consider the case of a pill comprised of an active ingredient in an inert medium. The placebo effect is any effect not due to the active ingredient. In principle, if you treat the active treatment arm and the placebo arm of a trial identically except that you give the placebo arm the pill minus the active ingredient, then you have controlled for all placebo effects (regardless of any knowledge you may have about their mechanisms).
 
jt512 said:
In principle, if you treat the active treatment arm and the placebo arm of a trial identically except that you give the placebo arm the pill minus the active ingredient, then you have controlled for all placebo effects (regardless of any knowledge you may have about their mechanisms).
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In a "spherical cow in a vacuum" sense yes. But that doesn't mean that all these effects are one thing that one interesting experiment can explain, in the way that the reporting suggests that the mouse study explains them.
 
arthwollipot said:
In a "spherical cow in a vacuum" sense yes.
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I have no idea what that means.

But that doesn't mean that all these effects are one thing that one interesting experiment can explain, in the way that the reporting suggests that the mouse study explains them.
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I haven't read about the mouse study you are referring to, and it doesn't matter. What I am telling you is that you don't understand what is meant in medicine by "placebo effect."
 
jt512 said:
The misconceptions you have expressed about what the placebo effect is, which I have corrected you on, are misconceptions, period. They do not depend on what some mouse study may or may not have to say.
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What I have been saying (recently) about the placebo effect are in direct reference to the mouse study referenced in this post.
 
What you wrote was wrong in any context.

You wrote:

"The placebo effect is defined as all of the responses that are not controlled for."

That is wrong.

You wrote:

"If you control for, say, regression to the mean in your clinical trial, then regression to the mean no longer contributes to the placebo effect in that trial."

That is worse than wrong. It is nonsense because regression to the mean is not a placebo effect.

You wrote:

"That doesn't mean that it [regression to the mean] is never a placebo factor..."

Regression to the mean is never a placebo effect, and a placebo, therefore, never controls it.

You wrote:

"If they [purported placebo effects] are known and can be controlled for, why are they still placebo? That doesn't make sense."

It makes total sense because placebo effects are exactly what a placebo controls.

I could go on, but I'll leave it to you to explain why any of the above statements would be correct in the context of a mouse study.


ETA: I've read the paper: https://www.internationalskeptics.com/forums/showthread.php?postid=14395913#post14395913
 
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When you're trying to find out whether a medical treatment actually works you need to carefully eliminate every confounding factor which might lead you to think it's having an effect when it actually isn't, whether those factors are real (i.e. measurable), all in the mind, or just the usual sources of error. Those who are interested only in whether the medicine they're testing is effective often lump all those factors under the umbrella term placebo effect. They don't care whether they're real, psychosomatic, errors, or a mixture of all three. They just want to eliminate them, and a double blind randomised clinical trial where the control group receive a placebo does that very well.

People who are interested in what those confounding factors are, and whether at least one of them might be real, often seem to reserve the term placebo effect for that subset of factors (a subset which might well be empty).

Having two definitions for the same term often causes confusion.
 
@arthwollipot: I have now read all of the mouse study paper except for the methods section. Nothing you wrote is correct in the context of that paper.
 
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Pixel42 said:
When you're trying to find out whether a medical treatment actually works you need to carefully eliminate every confounding factor which might lead you to think it's having an effect when it actually isn't, whether those factors are real (i.e. measurable), all in the mind, or just the usual sources of error. Those who are interested only in whether the medicine they're testing is effective often lump all those factors under the umbrella term placebo effect. They don't care whether they're real, psychosomatic, errors, or a mixture of all three. They just want to eliminate them, and a double blind randomised clinical trial where the control group receive a placebo does that very well.
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Yep.

People who are interested in what those confounding factors are, and whether at least one of them might be real, often seem to reserve the term placebo effect for that subset of factors (a subset which might well be empty).
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Agreed, though Arthwolipot seems to have reserved the term for the opposite group of factors, not the subset that is real, but the subset that is not.
 
Very interesting, this latter part of the discussion.

artwollipot, I'm having trouble wrapping my head around your linguistic argument. You seem to be defining placebo as necessarily a sham; and cutting away those portions of it that turn out not to be a sham after all, as therefore definitionally not placebo.

I mean, if placebo by definition is a sham, then we don't need studies about that focused question. That question, 'Is placebo real or a sham'', would then be conclusively settled at the definition stage itself.

But on the other hand: take the term, 'paranormal'. We do define it as not existing. If we study its claims, and find some of its alleged manifestations to be valid, including even such crazy stuff like telepathy; then we do immediately shift that portion away from the head Paranormal and under the head Stuff-your-brain-has-evolved-to-do.

So in that sense such linguistic contortions need not necessarily be misplaced.

The linguistics is probably the least important part of all this; and clearly there's no unanimity on this; but just to be clear: Is that how you'd explicitly like to define 'placebo'? As something that, like 'paranormal', necessarily is something that definitionally does not and cannot exist?

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If what this report seems to be showing is true --- IF --- then does that mean that things like homeopathy etc might have some valid application after all, in the form of placebo (or whatever we call it)? Particularly in situations where bona fide treatment may not be available --- either because there is none at all, or because that specific person or populace doesn't have access to it?

(Not arguing that that's so. I'm asking if that might be so, after all, basis this somewhat different angle now introduced.)
 
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