Talk:Placebo/Archive 1

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More discussion

Hello. This article needs many more off article talk. Placebo is confusing and many use it as excuses for misconduct in medicine and getting money for sugar tablets or holy water snake oil. Article is very good, but I will see if I can be adding some more info to the talk. Hylas Chung 08:52, 25 May 2006 (UTC)

- It seems that the term "placebo" is being used here to discount innefective treatments; what would be more interesting and beneficial is how this mysterious mind:body connection works and it achieves such amazing results. Placebo could be a word that covers a number of self healing mechanisms that have a very real effect. —Preceding unsigned comment added by 124.183.185.149 (talk) 07:11, 27 March 2008 (UTC)

Suggestion to merge

It is my intention to edit a merge of these two pages for several reasons.

(1) to make the placebo article symmmetrical with the article on the counterpart, derivative term nocebo.

(2) a certain amount of the confusion within and between the two current articles, and right throughout the available literature, is caused by the fact that there are several different applications of the term placebo, which are in their origins, correct application, and function, so different that they are clearly homonyms (rather, that is, being examples of an essentially contested concept, where people are disputing about what is the best and most ideal instantiation of a notion upon which they all agree).

(3) the historical reasons for the emergence of certain of these terminological usages need to be explained; in particular because some of them have been responsible for the emergence of derivative terms and concepts (e.g., nocebo).

(4) much of the controversy is generated by a failure to distinguish which kind of placebo is being spoken of.

I am suggesting that a combined entry, with clear sections on, for example, "what does the term placebo denote?", "Why placebo effect?", "why placebo response?", "Ambiguity of usage of terminology" and similar important items can be discussed, clearly described and elaborated, before any of the issues relating to the role, ethics and relevance of placebos in drug trials can be either understood or discussed.

Anyway, produced the current article on nocebo, I would be prepared to submit a merged article within a short time, for all to view and edit further.

Such a presentation, would then also allow readers to understand the issue in the realm of medicine, as raised by:

Stewart-Williams, S. & Podd, J., "The Placebo Effect: Dissolving the Expectancy Versus Conditioning Debate", Psychological Bulletin, Vol.130, No.2, (March 2004), p.326:

Finally, it is sometimes argued that placebo effects are, by definition, desirable effects. After all, the word placebo comes from the Latin meaning “to please,” and the archetypal placebo event involves an improvement in health. The undesirable effects of inert agents have been dubbed nocebo effects, and the agents producing them nocebos (Hahn, 1997). Just as inert agents can produce analgesia, they can also produce hyperalgesia (Benedetti & Amanzio, 1997). In the latter case, the inert agent would be a nocebo and the hyperalgesia a nocebo effect. However, there are several problems with the placebo–nocebo distinction. Inert agents may sometimes simultaneously produce both desirable and undesirable symptoms. For example, the response may mimic not only the healing effects of drugs and other treatments, but also some of their side effects (Shapiro, Chassan, Morris, & Frick, 1974). In such instances, we would have to say that the agent in question is both a placebo and a nocebo. It would be more parsimonious to say that the same agent (a placebo) can simultaneously produce both desirable and undesirable effects. Another problem is that the same effect might be desirable for one person but undesirable for another. For instance, placebo immunosuppression may be undesirable to most people but desirable to people suffering an autoimmune disorder (Olness & Ader, 1992). In this case, we would have to say that the former group had taken nocebos but the latter placebos, and we could not know which we had administered until we had established whether the recipients considered the effects desirable or not. Furthermore, although the same effect was produced in both cases, and presumably through the same mechanisms, by labeling one a placebo effect and one a nocebo effect, we would in effect be treating it as two different phenomena, simply because it was desirable to one group but not the other. These considerations lead us to suggest that, despite the origin of the word placebo, the desirability of the effect should not be part of the definition [of the terms placebo and placebo effect].
  • References
  • Benedetti, F., & Amanzio, M. (1997). The neurobiology of placebo analgesia: From endogenous opioids to cholecystokinin. Progress in Neurobiology, 52, 109–125.
  • Hahn, R. A. (1997). The nocebo phenomenon: Scope and foundations. In A. Harrington (Ed.), The placebo effect: An interdisciplinary exploration (pp. 56–76). Cambridge, MA: Harvard University Press.
  • Olness, K., & Ader, R. (1992). Conditioning as an adjunct in the pharmacotherapy of lupus erythematosus. Journal of Developmental & Behavioral Pediatrics, 13, 124–125.
  • Shapiro, A. K., Chassan, J., Morris, L. A., & Frick, R. (1974). Placebo-induced side effects. Journal of Operational Psychiatry, 6, 43–46.

--- It would look something like this (given that I have already merged 4, 5 & 6 under nocebo): I believe that we need the following six divisions to clearly disambiguate the mess:

(1) Placebo: describing the evolution of the term placebo, from the Septuagint version of the Psalms, as translated by Jerome into his first version of the Vulgate, and how this translation was used as the text for the Roman Catholic "Office of the Dead" ritual, etc.,etc. and how, following this thread, how the original term placebo has only one meaning: a simulator.

Then all of the applications of such a dummy simulator in medicine and pharmacology could be discussed.

A second section would also need to appear to detail the pejorative use of the term placebo -- in the period where modern scientific medicine was emerging from the morass of herbal medicine and traditional physic, and was atempting to dissociate itself from so-called "heroic medicine" -- to designate therpies that had once been thought efficacious, but were now found (per medium of this fore-runner of evidence based medicine) to be bereft of active ingredients.

A third section would need to appear to deal with the therapist-delivered placebo (essentially the legendary sugar pill) which embodied the notion that a placebo was a "pleaser".

All of this is because the issue of elaborating all of the considerably different aspects of all of the different sorts of placebo, requires such a sort of exposition.

(2) Placebo Effect: Stressing that this description ascribes agency to the drug. A short note stating that this was either the consequence of being given either a sugar pill, or of being given a dummy, inert, simulator (it didn't matter which) -- and, as a consequence, the administraion (in either case) of something which, both by definition, and by stipulation, contained no active substances, and therefore, could not logically be spoken of having any sort of substance-centred agency (as it was all subject-centred response). But, in addition, once the term placebo began to be used by some people to denote "an active and pleasing drug", it was then technically possible to speak of a placebo effect.


(3) Placebo Response: Essentially a matching piece to that which I have written about "nocebo response".


This would then lead on to (4) Nocebo; (5) Nocebo Effect; and (6) Nocebo Response: as it now apppears under nocebo.

Finally, due to the interwoven histories of the terms placebo, placebo effect, placebo reaction, placebo response, nocebo, nocebo effect, nocebo reaction, and nocebo response,I believe that everyone would be far better served if the two placebo sections are merged; and, as a consequence are symmetrical with article on nocebo.

Given all of the above, I must also add that I have thought about things for a very long time, and I really can't come up with any single argument against merging thhe two articles. Anyway, I offer this up for your consideration cogtrue 00:29, 1 June 2006 (UTC)

Surprised to see no response to your post for such a long time. I offer my views with regards to your arguments:
  1. The symmetry argument doesn't necessarily hold in my opinion as the terms "placebo" and "placebo effect" are well known while "nocebo" and "nocebo effect" are not. A search on Google results in 1,200,000 pages on "placebo effect" and 18,600 pages on "nocebo effect". So there is no symmetry in usage.
  2. The confusion within the articles will not necessarily be resolved by a merge. On the other hand, if a merge does resolve the confusion, there is no reasoin why the articles couldn't be separated again without causing confusion again.
  3. Could the emergence of various terms be explained satisfactorily but without going into too much detail in the main (placebo) article?
  4. Again, would a merge help clarify the term "placebo"? Not necessarily.
Having said all that, I am much in favour of your presentation of the article's structure. Providing such a structure will go a long way to alleviate all issues you are talking about. However, since the term "placebo effect" is widely used, I doubt you could simply merge ii into the main article.
In summary, I would favour a structured presentation of "placebo" as outlined, but also keeping the "placebo effect" article. This solution would integrate all features of your suggestion while leaving open the possibility for a detailed explanation of the "placebo effect." Aquirata 22:09, 15 June 2006 (UTC)

Hello. I think placebo and effect should be merge. But it should also be kept seperate. The merging one will be the top hierarchy and be summarized over time. The other ones can be linked. Redundant lines can be cut by good editing. Thanks. Hylas Chung 05:50, 27 July 2006 (UTC)

Hello, as a personn working in pharmaceutical industry, I think that placebo and placebo effect are two different things. A placebo is the reconstitued medicine without the active ingredient and if used by human can give a placebo effect, but placebo is also made for analytical tests. In this case no placebo effect. Secondly, placebo effect can be obtained by taken a placebo, but also for many other reason. for example when you take a medecine by oral route, you often feel better in few minutes in spite of it is still not in your blood.
that's why i think that it not the best idea to merge placebo effect and placebo.--Leridant 08:30, 1 August 2006 (UTC)

I also oppose the merge, the placebo effect is a significant topic worthy of its own article. Addhoc 12:54, 9 August 2006 (UTC)

I oppose too, Wiki should be easy to browse with common intuition which dictates in opposition to merger. (I'm an unregistered user) - a chemistry student from Israel.

I support the merge, very related topics. --Afa86 21:14, 4 November 2006 (UTC)

Symmetry in usage

On 15 June, in relation to Nocebo, Aquirata commented as follows:

The symmetry argument doesn't necessarily hold in my opinion as the terms "placebo" and "placebo effect" are well known while "nocebo" and "nocebo effect" are not. A search on Google results in 1,200,000 pages on "placebo effect" and 18,600 pages on "nocebo effect". So there is no symmetry in usage.

Whilst this comment is accurate, in one sense it is not entirely "correct".

The issue with the term "nocebo" (the bringer of harm) is that it is, essentially, a deviant usage that is being ever more actively discouraged in the technical medical literature. The term "nocebo" only exists because somebody has seen a need to produce a counterpart of the benefactor "type" of "placebo" (I am yet to complete that section of Placebo (origins of technical term)) -- the drug that produces a beneficial response -- namely, the drug that produces a harmful response.

Therefore, in a general sense, the 1,200,000:18,600 ratio is misleading; because it is far more a case of "every time somebody uses the deviant term "nocebo" it further cements the inaccurate "benevolent" usage of the corresponding term "placebo". Thankfully the majority of usages of the term placebo refer to an inert simulator; not to a "pleaser".

From the above, it is my intention to ensure that the "nocebo" and "placebo" articles reflect one another in an appropriate way -- when it is necessary -- and that the rest of the placebo article speaks of the dummy simulators. Lindsay658 05:49, 28 July 2006 (UTC)

Merge the articles.--Ncosmob 21:19, 4 August 2006 (UTC)


Redirect

The article for Derbisol redirects here, but Derbisol isn't mentioned on the page. Jeremymiles 18:40, 11 September 2006 (UTC)

Merger into paradox/irony/oxymoron

I think it would be more appropriate if placebo effect, as a phenomenon or whatever you call it, be merged under the class "oxymoron" or "irony". "Placebo", it must be stressed would be appropriate, but not the term "placebo effect". There is a vast difference between the two. Merging the two would only serve to blur the distinction and that would just confuse one and everybody. This is my humble perspective.Sriram sh 13:34, 18 October 2006 (UTC)

???? What do those subjects have to do with placebo or placebo effect? -- Fyslee 14:21, 18 October 2006 (UTC)

All that I wanted to say was that for anyone acquainted with pharmaceuticals and drugs, placebo and placebo effect are two different things. Of course, placebo effect could be broadly used in any sense one wants so long as the term gives the full extent of the meaning, which is, to say, a contradiction of sorts, and not just in the medical sense of the term. So, the articles MUST be separate and there is no ground for a merger.Sriram sh 10:09, 19 October 2006 (UTC)

Merging

I merged Placebo (origins of technical term) and Placebo (medicine) and Placebo Effect into Placebo, as they were less like distinct subjects and more like content forking of Placebo.

I split off Placebo (at funeral), as medieval funeral meal gatecrashers have no relevance to medicine. Anthony Appleyard 13:31, 13 December 2006 (UTC)

I have tidied and merged in Uses of the term placebo. Anthony Appleyard 09:47, 14 December 2006 (UTC)

Inline text or ref footnotes?

I prefer all text (except authors' names and dates and page numbers) to be inline, not in footnotes, as over 40 years of reading books I have had a weariness and tediousness of having to keep on leafing back and forth between the text and notes. Anthony Appleyard 09:47, 14 December 2006 (UTC)

Obecalp

There is an incoming redirect from Obecalp but no explanation of what Obecalp is in the text (yes, it's "placebo" backwards but there is no mention of context or whether it's an actual product). Wikipedia guidelines say that an incoming redirect should be explained in the first couple of paragraphs. -76.4.49.201 17:10, 29 January 2007 (UTC)

Article length

This article is rather long - too long? Ben Finn 15:17, 30 January 2007 (UTC)

Way too long! And it's almost unreadable! We need some serious cleanup and splitting here. — Kieff | Talk 19:03, 3 February 2007 (UTC)
Too long, but little grounds for splitting. The main problem is that there is too much detail on the historical clinical trials, some of which might merit their own entries (as relevant to the history of medicine) but many of which should simply be reduced to conclusion and citation. Ohwilleke (talk) 18:16, 6 March 2008 (UTC)
I think a series of mergers is to blame for this. Rather than a thoughtful combination of data, we get the same thing being said five different ways, for each of the five articles that were merged into this one. --Infophile (Talk) (Contribs) 18:20, 6 March 2008 (UTC)

Intro

The introduction is a bit weird, since it starts with a quote rather than a definition, followed by a parenthetical comment qualifying the quote. --Starwed 10:41, 23 February 2007 (UTC)

I agree, it is awkwardly written, almost enough to justify a cleanup tag. If I knew anything about the topic I would rewrite it myself. GofG ||| Contribs 14:01, 06 day of march sincerly melissa seymour miami dade college(UTC)
I took the liberty, and hope this version meets approval of others. --Ginkgo100talk 20:16, 24 March 2007 (UTC)

Placebo in psychotherapy

The lead seems to say that it is only medicines that have the placebo effect. Also types of psychotherapies have no real effect other than the placebo. And also accupunture and chiropractic. ProtoCat 19:38, 10 May 2007 (UTC)

I believe that "medication or treatment" might be a better way of encompassing all. However, like everything on Wikipedia, we need a reliable source which documents/defines this. Any thoughts or suggestions? -- Levine2112 discuss 21:54, 10 May 2007 (UTC)
Despite the movement of this article towards becoming an almost exclusive account of pill-popping, I suggest that your needs will be met by using the far more general and far more appropriate term "therapeutic intrusions"?
Given that, in the absence of it being applied with some sort of therapist intention, the entity in question can not be considered to be a "placebo" — regardless of whether it be animal, mineral or vegetable, or whether it be a chemical or simply "talking".
Despite all of the ramblings that one might read, a placebo is always a "placebo"-counterpart of some other thing!
And that particular "some other thing" is always (at least in a medical sense) a therapeutic intrusion.
From this, therefore, whatever is designated placebo is the "active" therapeutic intrusion, from which the supposed active ingredient has been removed.
From this, and despite the movement within this article to maroon the core concept placebo onto a remote island called "sugar pill" (the reason why I am no longer contributing to the article!), a placebo is always a counterpart of some "thing" (i.e, it can never be in, and of itself a placebo, it is always a placebo-counterpart of an "active" something else).
Anyway, I suggest that "therapeutic intrusions" sufficiently reflect the fact that the intrusions are performed with a deliberate intention.
Also, btw, the July 2005 edition of the Journal of Clinical Psychology (i.e., Vol.61, No.7, contains a significant number of papers that address the various issues connected with the use of "placebo"-type controls in the appraisal of the effectiveness of various sorts of psychotherapy. Perhaps that might be the first place for you to look?Lindsay658 02:37, 11 May 2007 (UTC)
"Therapeutic intrusions". Thanks for that, Lindsay658. You taught me something! So, is it a misuse of the term "placebo effect" to explain some people's rationale of why certain alternative medicines (for instance) appear to be effective? (And of course, per your definition, I mean a therapy that is pill-less.) -- Levine2112 discuss 02:56, 11 May 2007 (UTC)

Brief answer. No time for greater detail. Sorry!

(a) In my view (based on a considerable amount of detailed study of such things), from the origins and original application of the term placebo (by scientists, that is), it is inescapably correct and irrevocably true that, given that a placebo is (in terms of drug therapy):

the entire conglomerate of active drug,
PLUS the entire drug administration ritual,
PLUS all of the other things and paraphernalia that accompany an "active treatment" (including the diagnostic, prognostic, prescription and other rituals)
MINUS whatever it might be that the "received wisdom" supposes (or, hopefully, the accurate scientific knowledge knows) is the chemical that is uniquely responsible for the therapeutic changes routinely observed whenever that "active drug" is administered,

the usage of the term placebo is only appropriate in circumstances where the response of a group of subjects:

(i) to the entire drug administration ritual, etc. PLUS the format of the drug (without the designated" "active ingredient, that is)
is being contrasted with
(ii)another group of subjects that have received the "active drug" per medium of all of those rituals.

This, then, gives a measure of the (a) extent to which a subject is responding to the "active ingredient" itself, contrasted to (b) the extent to which subjects simply respond to the rituals themselves.

(For example, Kirsch has found that whenever the efficacy of "active drugs" and their "placebo counterparts" have been contrasted in tests in which subjects are completely unaware that any administration has taken place, there is always a zero result from the placebos. In other words, a subject is 100% responding to the rituals; and, in the absence of any knowledge that the ritual has taken place, there is nothing for them to respond to.)

(b) Whenever somebody says something about a response to, say, an acupuncture treatment as being "just a placebo", they are saying three things:

(i) they are accepting that there has been, indeed, some sort of change in the subject;
(ii) they are unable, within their understanding of the universe, to identify an "active ingredient"; and
(iii) as a consequence of (ii) the only conclusion they can draw is that somehow the changes have been generated though some sort of psychosomatic factor (i.e., something in the mind has been able to produce a change in the body)

(c)In the realms of "talking" psychotherapy, the issue of placebo controls in testing treatment efficacy becomes far more than just an abstract intellectual, philosophical question -- for, if one is to test the efficacy of a particular therapeutic intrusion by contrasting "active treatment" against "placebo treatment", one must be able to identify the "active ingredient" (so that, of course, it can be present in the first and absent in the second.

Now, in addition to the difficulty of isolating indisputably "active ingredients" a further problem arises: if there are no "active ingredients", then is any and all of the observed efficacy due to the therapeutic rituals alone?

(d)Kirsch and his colleagues, to me, seem to be on the right track when they speak of trials that contrast the efficacy of "active drugs" and their "placebo counterparts" as actually measuring something that they call "response expectancy"; and in their opinion, it is the individual subject's own level of "response expectancy" that dictates the level to which they will "respond" to the rituals (regardless of whether the "active ingredient" is present or absent).

(e)Lastly, an I don't want to re-open this can of worms in relation to those who are now driving this article in such a counter-productive "placebo effect" direction, there is no such thing as a placebo effect! There can't be; simply because, by definition, in terms of its target condition, the placebo is always 100% inert. The only thing one can legitimately speak of is a "placebo response" within a subject; there is never any sort of "placebo effect" hidden somewhere within the drug.

Hope that helps. In hasteLindsay658 04:48, 11 May 2007 (UTC)

Remarkable! If that was in haste, I imagine you can write a dissertation of the subject. It makes me think that the term "placebo effect" is actually a paradoxical oxymoron. To summarize, it sounds as though you are saying that the term is often (if not always) misused. -- Levine2112 discuss 16:43, 11 May 2007 (UTC)

Upon reflection, I realize that the term "therapeutic intrusion" could be construed as being intentionally applied with some pejorative connotation, for some antagonistic purpose. I would propose that, for those sorts of reason, the term "therapeutic intervention" seems to be far less provocative; and, as well, in terms of the normal, conventional sorts of medical discourse, it also seems to be quite a well-worn medical expression anyway.Lindsay658 04:51, 14 May 2007 (UTC)

I have added a section on the concept of placebo to an already long and discursive article, believing this needed some treatment. However I'd be interested in joining a cooperative clean-up of the whole thing if others are interested. John PriceJohnHarmonPrice 11:17, 14 May 2007 (UTC)

I'm not sure I agree with Lindsey's definition: Many alternative therapies have been tried and shown to have no better response than a placebo, therefore, it's reasonable to presume that improvements seen from them in practice are due to a "placebo effect". Indeed, the very reason why placebos are necessary is because of the very act of treatment having an effect.
Unless Lindsey can show a reliable medical source making that claim, I cannot agree with him. Adam Cuerden talk 16:04, 15 May 2007 (UTC)
Adam Cuerden: somewhere you seem to have your wires crossed. What you have written agrees with my position 100% (and, also, what you have said reflect what I have said).
Except, of course, that you have made the conventional category mistake of referring to a "placebo effect", when there can never be a placebo-centred-agent-of-change, and there can only be a subject-centred-response.
BTW this is where the "placebo effect" confusion all began, in a number of the early papers that spoke of subjects having subject-centred placebo responses the authors happened to parenthetically remark that it was obvious to anyone with any clinical experience that, in many cases, placebo drugs were efficacious (i.e., in many cases when dummy treatments were administered, patients got better), and the comprehensive misunderstanding of these parenthetical comments (or, in the majority cases, a total failure to read the original papers), have led many to incorrectly maintain the view that these authors were speaking of placebo-centered agency.Lindsay658 18:36, 15 May 2007 (UTC)
Oh, is that what you meant? Sorry, I misread your objection to the term as a rejection of the possibility of psychological effects skewing clinical outcomes, and particularly misread your section ending "(iii) as a consequence of (ii) the only conclusion they can draw is that somehow the changes have been generated though some sort of psychosomatic factor (i.e., something in the mind has been able to produce a change in the body)" which I thought implied that that wasn't a valid opinion; that the alternative/ineffective treatment actually had important merit that the scientist didn't see. I agree with you that "placebo effect" is a poorly-chosen phrase, and placebo response is what's really meant, but we provbably have to provisionally accept the term, because it's so widespread. Of course, we do need to be perfectly clear that the so-called "placebo effect" is instead just a tendency to expect to feel better, and using confirmation bias and other mild delusions on yourself to see improvement, and perhaps force yourself to do things you didn't think you could. As far as I know the literature, it doesn't cause any changes to anything that can't be affected by mood, e.g. tumor growth rates, but can work well on psychological effects of diseases like pain or depression. Adam Cuerden talk 02:51, 16 May 2007 (UTC)
I think the first sentence should include the word treatment as in psychotherapy. FatherTree 21:30, 23 May 2007 (UTC)

Changes that have been reverted

Anthony Appleyard (talk · contribs) has reverted my edits and requested it be discussed.

Per my first change, I moved the "Meanings of placebo" section to the Placebo disambig page. It is more suited there since most of the meanings aren't directly related to the general meaning assumed in the article.

My second change, I removed the "Notable absences of placebo effect" section. This has been uncited since February and is very questionable since it offers no explination or further details. Not enough information for an entire section anyways.

My last change was removing the unecyclopedia summary section, located at the bottom of the article. There is no need to rehash the entire article in an unorganized, bulleted list. The article is already overly long and this section provides nothing benefetial to the article, since it is already sumarized at the beginning of the article. Also, why are there questions in the section? This isn't an elementary school text book with a quiz and a summary at the end of a lesson. --Android Mouse 05:47, 15 June 2007 (UTC)

Revert

I have reverted User:Anonywiki's recent block of edits in their entirety, since they consist only of unsourced POV. —Ashley Y 08:26, 26 July 2007 (UTC)

Just because there are no citations, doesn't mean "they consist only of unsourced POV". The page was a mess and I made it more neutral and correctly stated that giving a placebo as an actual treatment is rare and quite pseudoscientific.

I'm sure if you go to the homeopathy page you are told that it's pseudoscientific and that very few doctors practice it, why not here? After all, homeopathy has the same effect. Talking about studies always conveys a POV.

Large studies have said placebo=bad and were at the top of the article as well as one or two studies saying placebo=good. They were removed and replaced with studies ALL saying placebo=good. So I took them out, please do NOT revert my edit, it's clear that having no study at all is NPOV. Anonywiki 03:13, 6 August 2007 (UTC)

Please read WP:RS and WP:NPOV. —Ashley Y 07:10, 6 August 2007 (UTC)

References added

References were added and a medical definition of Placebo effect as well as it seems that the article was concentrated in placebo medicines and forgetting placebo healing procedures. The article has been placed under the WP:MED scope ℒibrarian2 20:01, 25 August 2007 (UTC)

WikiProject class rating

This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot 04:22, 10 November 2007 (UTC)

Reference link?

Does anyone have a link for this PDF article cited in the Methodology of administration section? Thanks.

M. Nimmo (2005) Placebo: Real, Imagined or Expected? A Critical Experimental Exploration Final year undergraduate Critical Review, Dept. of Psychology, University of Glasgow. PDF copy.

Bricker (talk) 00:20, 11 December 2007 (UTC)

Hi Bricker. Yes, it is http://www.psy.gla.ac.uk/~steve/placebo.pdf - Tekaphor (talk) 02:05, 11 December 2007 (UTC)
Much obliged to you, Tekaphor. Bricker (talk) 10:16, 11 December 2007 (UTC)

Relevance?

Are the sections "Willow bark" and "Mercury for syphilis" relevant to the subject of placebo? If so, this should be made clear in the text, currently it isn't. 192.122.223.171 (talk) 12:48, 6 January 2008 (UTC)

Are controlled studies REALLY designed to disadvantage the placebo condition?

I question the statement that 'It is a view held by many "that placebo-controlled studies often are designed in such a way that disadvantages the placebo condition"[18].' First of all, 'it is a view held by many' is a classic example of a phrase used by a writer on wikipedia who wants to promote their own point of view but hide behind an attribution of the view to an unspecified "many." This at first blush reads like point of view pushing. Second, anyone who is competently designing a performing a controlled clinical study will take great pains to try to make the test condition and the control (placebo) condition identical in every way except the medication vs. placebo. That's the whole purpose of having a control condition in the first place! Anyone who is designing a clinical trial to disadvantage the control condition is simply being unethical. If they documented the ways they biased against the placebo condition, the study would challenged at the time of peer-review and likely not accepted for publication. If they bias against the control condition and DON'T document this, they're being unethical, vulnerable to a scandal if someone blows the whistle, and putting their own careers at risk.

I suggest simply rewriting this sentence to state something like "For a new drug to be accepted for general clinical use, it must typically show a statistically significant improvement compared to the placebo condition." —Preceding unsigned comment added by AIDSvideos (talk • contribs) 17:32, 12 January 2008 (UTC)

I'm inclined to agree here...the reference for the above claim is "(Herbert and Gaudino, 2005, pp.788–789)" with no actual indication of more publication details. It does sound weasel-ly. — Scientizzle 18:17, 12 January 2008 (UTC)

cleanup tag

i've put one on as it's a mess, right from after the contents, as this talk page admits. it's also overlong --Mongreilf (talk) 11:18, 17 January 2008 (UTC)

Children and animals

The argument is used again and again in Talk:Homeopathy (and sometimes in the article itself), that the positive result from such-and-such a trial (or anecdote) cannot be explained by the placebo effect because the subjects were children (babies) or animals. The possibility that adults/humans with knowledge of whether the subject is receiving a verum or placebo can unconsciously influence the subject, or that the measures of improvement, even if they are largely objective, can be influenced by the knowledge of those evaluating the conditions of the subjects, are often not recognized. It would be helpful if this article could include a section on this topic. --Art Carlson (talk) 14:27, 25 January 2008 (UTC)

even though there may be no placebo effect, there could be other non-specific effects, such as just giving attention to the subject. There are often many non-specific effects that could possibly alter the subject. —Preceding unsigned comment added by 158.132.12.81 (talk) 02:24, 27 March 2008 (UTC)

Potentially useful refs

I'm just listing these here as I find them - I haven't looked yet to see how many are already used in the article - but here goes:

  • PMID 15266510 - Cochrane Library review of the placebo effect
  • PMID 11372012 - NEJM 2004
  • PMID 12406519 - Definitions of placebo
  • PMID 18226748 - Contains a useful, if brief, history in the full-text version.
  • PMID 18250260 - Biochemical mumbo-jumbo...
  • PMID 16280578 - ... and a review article covering the same.
  • PMID 14976306 - If it's in Science, it must be true.
  • PMID 15377572 - Physician attitudes toward placebo.
  • PMID 16549251 - a 2006 review article from the NIMH.

Any others? I'll keep an eye out. Once I've gathered a few I'll start working on the article. MastCell Talk 22:10, 4 March 2008 (UTC)

Here's a good one: Waber RL, Shiv B, Carmon Z, Ariely D (2008). "Commercial features of placebo and therapeutic efficacy". JAMA. 299 (9): 1016–7. doi:10.1001/jama.299.9.1016. PMID 18319411.{{cite journal}}: CS1 maint: multiple names: authors list (link) — Scientizzle 01:59, 9 March 2008 (UTC)

A few more references, often more practice oriented:

--Hans Adler (talk) 21:21, 25 April 2008 (UTC)

Redundancy

While going through the article to fix section headers, I noticed that a lot of the information here seems to be redundant. One major way this article could be improved would be to compress a lot of that together.

Also, there's a lot of information on studies on the placebo effect here. Perhaps we could fork that to its own article? --Infophile (Talk) (Contribs) 19:33, 5 March 2008 (UTC)

Relative Strength

While many sections of this article are excessively detailed, one are of wide general interest is not discussed in detail. For which conditions have the placebo effect been strong, and for which have they been relatively modest. No comprehensive data is called for, but examples at the low, medium and high end of the range would be useful. The fact that there is a wide variation is mentioned, but there is no follow up information. Ohwilleke (talk) 18:20, 6 March 2008 (UTC)

Cleanup

This article had a chaotic mixture of Harvard references and footnote references. I have ordered the references alphabetically, categorised them (books, research, general audience), and converted all footnote references into Harvard style. There are still a couple of footnotes left: Harvard references look a bit strange in the lede, and in some cases further down there were additional references. I have also removed four(!) references related to the old testament, and with no obvious connection to the article.

Based on the theory that the article is currently so disorganised that I can't make its structure worse, I will now organise it into three chapters: Placebos, Placebo effect, and Placebo-controlled studies. I hope that's OK for the regulars here. --Hans Adler (talk) 15:05, 26 April 2008 (UTC)

I have removed the following references from the list of historical or modern research papers because they were not used. The lists are so long that these papers don't serve any purpose there if they are not cited.

  • Bacon, R., Of Simulation and Dissimulation, 1597.
  • Charcot, J.M., "The Faith-Cure", The New Review, Vol.VIII, (January 1893), pp.18–31. Medical examination of Lourdes miracles.
  • Goddard, H.H., "The Effects of Mind on Body as Evidenced by Faith Cures", American Journal of Psychology, Vol.10, No.3, (April 1899), pp.431–502.
  • Houston, W.R., "The Doctor Himself as a Therapeutic Agent", Annals of Internal Medicine, Vol.11, No.8, (February 1938), pp.1416–1425.
  • Merton, R.K., "The Unanticipated Consequences of Purposive Social Action", American Sociological Review, Vol.1, No.6, (December 1936), pp.894–904. [1]
  • Aronson, J., "When I use a word … Please, please me", British Medical Journal, Vol.318, No.7185, (13 March 1999), p.716.
  • Di Blasi, Z., Harkness, E., Edzard, E., Georgiou, A. & Kleijnen, J., "Influence of Context Effects on Health Outcomes: A Systematic Review", The Lancet, Vol.357, No.9258, (10 March 2001), pp.757–762.
  • Ernst, E. & Resch, K.L., "Concept of True and Perceived Placebo Effects", British Medical Journal, (26 August 1995), Vol.311, No.7004, pp.551–553.
  • Evans M. 2000. Justified deception? The single blind placebo in drug research. J Med Ethics. 26:188–193. PMID 10860211.
  • Hahn, R.A. & Kleinman, A, "Belief as Pathogen, Belief as Medicine: "Voodoo Death" and the "Placebo Phenomenon" in Anthropological Perspective", Medical Anthropology Quarterly, Vol.14, No.4, (August 1983), pp.3, 16–19.
  • Jacobs, B., "Biblical Origins of Placebo", Journal of the Royal Society of Medicine, Vol.93, No.4, (April 2000), pp.213–214.
  • Kirsch, I., "Response Expectancy as a Determinant of Experience and Behavior", American Psychologist, Vol.40, No.11, (November 1985), pp.1189–1202.
  • Kirsch, I., "Response Expectancy Theory and Application: A Decennial Review", Applied and Preventive Psychology, Vol.6, No.2, (Spring 1997), pp.69–79.
  • Lasagna, L., "The Placebo Effect", The Journal of Allergy and Clinical Immunology, Vol.78, No.1, Pt.2, (July 1986), pp.161–165.
  • Lorenz, J., Hauck, M., Paura, R.C., Nakamura, Y., Zimmermann, R., Bromm, B. & Engela, A.K., "Cortical Correlates of False Expectations During Pain Intensity Judgments — A Possible Manifestation of Placebo/Nocebo Cognitions", Brain, Behavior, and Immunity, Vol.19, No.4, (July 2005), pp.283–295.
  • McDonald CJ, McCabe GP. 1989. How much of the placebo 'effect' is really statistical regression? Stat Med. 2:417-27. PMID 2814076.
  • McGlashan, T.H., Evans, F.J. & Orne, M.T., "The Nature of Hypnotic Analgesia and Placebo Response to Experimental Pain", Psychosomatic Medicine, Vol.31, No.3, (May-June 1969), pp.227–246.
  • McMahon, C.E., "The 'Placebo Effect' in Renaissance Medicine", Journal of the American Society of Psychosomatic Dentistry and Medicine, Vol.22, No.1, (1975), pp.3–9.
  • McMahon, C.E., "The Role of Imagination in the Disease Process: Pre-Cartesian History", Psychological Medicine, Vol.6, No.2, (May 1976), pp.179–184.
  • McMahon, C.E. & Hastrup, J.L., "The Role of Imagination in the Disease Process: Post-Cartesian History", Journal of Behavioral Medicine, Vol.3, No.2, (June 1980), pp.205–217.
  • Miller, F.G., "Sham Surgery: An Ethical Analysis", The American Journal of Bioethics, Vol.3, No.4, (Fall 2003), pp.41–48.
  • Miller, F.G., "William James, Faith, and the Placebo Effect", Perspectives in Biology and Medicine, Vol.48, No.2, (Spring 2005), pp.273–281.
  • Pyysiäinen, I., "Mind and Miracles", Zygon, Vol.37, No.3, (September 2002), pp.729–740.
  • Rajagopal, S., "The placebo effect". Psychiatric Bulletin, Vol.30, (2006), pp.185–188.
  • Senn SJ. 1988. How much of the placebo 'effect' is really statistical regression? [letter] Stat Med. 7:1203. PMID 3201046.
  • Senn SJ. 1992. The ignoble lie [letter; comment]. J Clin Epidemiol. 45:1338–40.
  • Senn SJ. 1996. A personal view of some controversies in allocating treatment to patients in clinical trials. Stat Med. 14:2661–74. PMID 8614742.
  • Senn SJ. 1997. Are placebo run ins justified? [letter] BMJ 314:1191–3. PMID 9146400.
  • Senn SJ. 2001. The Misunderstood Placebo. Applied Clinical Trials 10:40–46.
  • Senn SJ. 2002. Ethical considerations concerning treatment allocation in drug development trials. Statistical Methods in Medical Research volume 11, pp.403–411.
  • Shapiro, A.K., "A Contribution to a History of the Placebo Effect", Behavioral Science, Vol.5, No.2 (April 1960) pp.109–135.
  • Staats, P., Hekmatb, H. & Staats, A., "Suggestion/Placebo Effects on Pain: Negative as Well as Positive", Journal of Pain and Symptom Management, Vol.15, No.4, (April 1998), pp.235–243.
  • Stam, H.J. & Spanos, N., "Hypnotic Analgesia, Placebo Analgesia, and Ischemic Pain: The Effects of Contextual Variables", Journal of Abnormal Psychology, Vol.96, No.4, (November 1987), pp.313–320.
  • Stam, H.J., Hypnotic Analgesia and the Placebo Effect: Controlling Ischemic Pain, (Ph.D. Dissertation), Carleton University, (Ottawa, Canada), 1984.
  • Stewart-Williams, S. & Podd, J., "The Placebo Effect: Dissolving the Expectancy Versus Conditioning Debate", Psychological Bulletin, Vol.130, No.2, (March 2004), pp.324–340.
  • Walach, H., "Placebo and Placebo Effects – A Concise Review", Focus on Alternative and Complementary Therapies, Vol.8, No.2, (June 2003), pp.178–187.
  • Wampold, B.E., Minami, T., Tierney, S.C., Baskin, T.W. & Bhati, K.S., "The Placebo is Powerful: Estimating Placebo Effects in Medicine and Psychotherapy from Randomized Clinical Trials", Journal of Clinical Psychology, Vol.61, No.7, (July 2005), pp.835–854.

--Hans Adler (talk) 22:10, 26 April 2008 (UTC)

Early history of placebos

Compassion, and not raillery, is to be bestowed on the hypochondriac, as the firm persuasion which he entertains will not allow his feelings to be treated as imaginary, nor his apprehension of danger to be considered as groundless, however the physician may be of opinion, that it is the case in both respects. To gain his confidence, it will be necessary to attend to his complaints, as if they were all real; and to satisfy him, it will by all means be advisable to give him some kind of innocent medicine or placebo, changing it from time to time, whenever he expresses any disappointment of relief. The general health is at the same time to be put into the best state possible. — Robert Thomas (1813), The Modern Practice of Physic, 4th ed., London, p.309. (Perhaps we can use this.) --Hans Adler (talk) 19:57, 26 April 2008 (UTC)

Mention of a "mock-heroic placebo" in 1803. [2]. A placebo ineffective for Syphilis, 1809. [3] --Hans Adler (talk) 20:30, 26 April 2008 (UTC)

Flawed logic in a placebo effect ?

Suggestion:

The "Placebo Effect" and another possible solution.

In most tests dealing with new and experimental drugs, the 'placebo effect' (often a dummy simulator) shows that 'it' also improves the medical condition in some patients as well.

Could it be that the 'placebo' can actually improve some conditions, as it is made of something, or can it be the simple fact that taking 'a simple glass' of water three times a day can help with certain medical symptoms ?

To truly check with the placebo effect, may involve other possible causal factors that are not being examined ?

--Caesar J. B. Squitti  : Son of Maryann Rosso and Arthur Natale Squitti 16:54, 23 June 2008 (UTC)

The placebo effect exists: undue weight to a minority opinion

There are overwhelming evidence (gathered during more than a century) for the existence of the placebo effect. Part of the text in the section Placebo#Doctor-patient_relationship gives undue weight to the minority opinion that there is a significant controversy about the existence of placebo effect. IMO that section should be made shorter or moved to the end of the article to a new section labeled "controversy". MaxPont (talk) 07:47, 3 October 2008 (UTC)

I am not an expert, and I don't know if the controversy has been more or less settled by now. In case the current placement of the section is part of the problem, it was created by me when I reorganised the article radically. You might want to look at the version before I started. At the time the section was between Placebo#Ethical challenges and concerns and Placebo#Use as morale-boosters. It may have to be modified for the current position. I am sure the article still has many similar problems.
IIRC, there have been discussions about making this article the Article of the Month both in WikiProject Pharmacology and in WikiProject Medicine. I think the main reason it hasn't happened yet is that people agreed it should be a joint endeavour, which made starting it a bit more complicated than just proposing it on a talk page. That's why I didn't continue work on this article: I hoped that the experts would be taking over soon. I don't feel qualified to change any value statements here other than the most obvious blunders. --Hans Adler (talk) 08:19, 3 October 2008 (UTC)
The article is clearly too long. In my opinion Placebo#Placebo-controlled studies should be split off. Perhaps we can also split off another article with the scientific discussion. Then this article could talk about physical pills etc. and the history of placebo use, and give only summaries of the subarticles, with "main article" links pointing to the new articles. --Hans Adler (talk) 08:31, 3 October 2008 (UTC)
I agree that the suggestion that the placebo effect does not exist should not receive much space. I also agree that the material about the design of clinical trials should be moved elsewhere. Colonel Warden (talk) 17:01, 8 November 2008 (UTC)
The section should be very much reduced, and the lead, which has been changed twice without discussion, should be changed back to remove this material per WP:UNDUE. Verbal chat 20:06, 8 November 2008 (UTC)
I'm probably missing something here, since I haven't been following these discussions for some time, but if the article really suggests "that the placebo effect does not exist," (CW above) that needs to be changed. Where does the article say that, or is this a straw man? Saying that the very real placebo effect (Hróbjartsson and Gøtzsche don't deny its existence) is mainly a subjective effect, is not the same as saying that it doesn't exist. It's just saying that it has been misunderstood, and that its efficacy for creating objective effects on serious illnesses has been greatly exaggerated, and their metanalyses of all the literature showed that to be true. -- Fyslee / talk 06:11, 10 November 2008 (UTC)

Not just suggestion

The lead reads "Any therapeutic effect is thought to be based on the power of suggestion." But the BBC radio show "Placebo" by Dr Ben Goldacre broadcast Monday 18 and 25 August 2008 on BBC Radio 4 has, Prof. Ted Kapchuk(sp?) Harvard Medical School "... Partly expectation , maybe a conditioned response. ... We know animals have placebo effects and thats not likely to be a cognitive expectation."

And from other sourcce It has also been suggested that the placebo effect is triggered by a Pavlovian response. Just as the dogs in Pavlov's famous experiment started drooling as soon as they heard the sounds that signalled feeding time, people might recover when a doctor gives them a pill as long as they have had a similar experience in the past. cites R.A. Ader, N. Cohen: "Behaviorally conditioned immunosuppression," Psychosomatic Medicine, 1975; 37: 333-340 "When mice were given a sweet drink containing cyclophosphamide, a substance that suppresses the immune system, they became weak and nauseated. When given the sweet drink without cyclophosphamide, they showed the same symptoms."

The quoted lead sentence also begs the question, "What is the power of suggestion?" At present WP re-directs the phrase to Psychosomatic medicine which gives absolutely no physiological mechanism. We seem to be sending readers on a goose chase. 124.169.104.133 (talk) 17:07, 5 November 2008 (UTC)

You are correct. This article is deficient in explaining all the possible components of the placebo effect, including expectation & conditioned responses, self-limiting illness, practitioner expectations and bias, subjective effects vs. objective symptom improvement, and study flaws (particularly in blinding and randomization).
This research article, if not already cited, is particularly facinating & relevant. This one, too. — Scientizzle 22:49, 5 November 2008 (UTC)

Existence of placebo effect in intro

A short sentence in the intro questioning the existence of an objective placebo effect (based on the most reliable and largest scientific analysis of the effect that exists so far and that is described in some detail down in the article) has been removed by Verbal [4]. I consider the removal of this essential and critical information a biased act. I will put it back and expect a discussion here before anybody is going to remove it again. Cacycle (talk) 18:51, 8 November 2008 (UTC)

See the section above: "The placebo effect exists: undue weight to a minority opinion". Please do not edit war. Per WP:UNDUE and WP:LEAD this should not be in the lead, and per WP:BRD we should be discussing this (although it has already been discussed) not editwarring (it's not BRRD). Please consider a self revert, and remove (not strike) your personal attack above (per WP:AGF and WP:NPA). I realise you're an administrator so I shouldn't have to remind you to be WP:CIVIL. All the best, Verbal chat 20:04, 8 November 2008 (UTC)
What bothers me here is that User:Cacycle is trying to include an inaccurate interpretation of what is stated further down the page. Consequently, I have edited it to now say "Despite its wide acceptance, one study suggests that the placebo effect is largely subjective" which is accurate. It previously stated (the authors' conclusion) was that "an objective placebo effect does not exist". It did not, and it is not encyclopedic to say so. Kaiwhakahaere (talk) 20:31, 8 November 2008 (UTC)
I really think it should be removed, but I don't want to start/continue an edit war. Verbal chat 20:34, 8 November 2008 (UTC)
I too would have made that revert if I had seen it. They do not say that it doesn't exist. That's a misunderstanding. See my comment at the end of the previous section, which I should maybe copy to this section as well. -- Fyslee / talk 06:17, 10 November 2008 (UTC)

On the one hand we have implicit and unquestioned assumptions of a placebo effect and merely anecdotal evidence, on the other hand we have the strong scientific evidence from meta-analyses of all existing clinical trials that have ever been published (!). Both the main study as well as the follow up study were specifically designed to objectively test the existence of a placebo effect. Both studies found that an objective placebo effect did not exist in that data set and that very minor (!) effects, seen only for self-reported outcomes, could not be distinguished from bias. I am not aware of any scientific evidence questioning the results of these studies.

Verbal: Giving the most powerful and scientific evidence that we currently have a representation in the introductory section does hardly put undue weight on this information and omitting it violates our NPOV policies. Please also note the careful wording: it said "suggests that an an objective placebo effect does not exist".

Kaiwhakahaere: Your version that the "placebo effect is largely subjective" does not accurately reflect the scientific evidence, which is that there is no clear and strong placebo effect (at least not in the data of all ever published clinical studies).

Cacycle (talk) 21:10, 8 November 2008 (UTC)

Your understanding of the science here seems to be a bit flawed. I suggest you join the discussion above. This is still only one review study, and it is too early to tell where this may lead. Your personal attack and failure to assume good faith hasn't yet been removed, and you have already edit warred for your preference. Please join in the discussion above where currently the consensus is against you. I'm interested in what my bias could be? Perhaps I'm in the pay of Tate&Lyle... Verbal chat 21:17, 8 November 2008 (UTC)
It was not my intent to attack you and I am sorry if I did. I am not sure which specific part of my responses you find offensive (other than that I think removing critical and essential information introduces POV bias (and it was actually you who started the bias-calling in your edit summary)). Cacycle (talk) 22:35, 8 November 2008 (UTC)
We have moved on since Hrobjartsson and Gotzsche's study. Please see this recent article which indicates that objective effects have been found in a "wave of studies" and that large numbers of doctors continue to prescribe placebos. In any case, the objective/subjective point seems logically weak since, from the observers' standpoint, patient reports of their condition are objective evidence. Colonel Warden (talk) 21:41, 8 November 2008 (UTC)
Indeed, CW has it spot on. Verbal chat 21:53, 8 November 2008 (UTC)
Not really. The "wave of studies" refers to studies of brain reactions (subjective effects obviously cause them), not to objective treatment effects that cause any real and lasting effects on serious illnesses. Patient reports are objective evidence that they have experienced something subjective. There's nothing more to it than that. I know of no significant research finding that has shown Hrobjartsson and Gotzsche's conclusions to be incorrect. -- Fyslee / talk 06:31, 10 November 2008 (UTC)

Part of the confusion probably stems from the many meanings of the term placebo and placebo effect. Hrobjartsson's studies do not question the use of placebo controls (mock treatments) in clinical studies, they do not address the prescription of placebos by doctors to meet patient expectations, and they are not questioning that you can create study conditions to bias health-related personal reports. I thought I reflected this by writing about an "objective placebo effect". Colonel Warden: I am not sure what you mean by saying that "We have moved on since Hrobjartsson and Gotzsche's study". Are you aware of any recent contradictory scientific evidence or reliable studies questioning their methodology? A shallow popular article in the Economist that does not even mentions Hrobjartsson's studies is not a reliable source for such a statement. After all, the studies we are talking about are meta-analyses, the most powerful and most decisive type of scientific studies that exists. Cacycle (talk) 22:35, 8 November 2008 (UTC)

The Economist is a source of the highest quality. And their article does mention Hrobjartsson, along with other experts in the field. Colonel Warden (talk) 23:08, 8 November 2008 (UTC)
The article does not address Hróbjartsson and Gotzsche studies. They cite a study that by design is not able to test for a real placebo effect against reporting bias (see my extensive explanation below) - their design actually maximizes reporting bias. Cacycle (talk) 02:09, 9 November 2008 (UTC)
The work of Hrobjartsson and Gotzsche is significant, and certainly deserves to be mentioned in the article. But few other people seem to agree with their conclusions, see for example this symposium. Therefore it does not need to be mentioned in the lead, and I am going to remove that mention. Even the discussion in the body could well be followed by a summary of counterarguments. looie496 (talk) 22:11, 8 November 2008 (UTC)
Please could you try to find reliable references that specifically address Hróbjartsson and Gotzsche studies or that provide newer evidence for or against their conclusion (the provided reference does neither address these studies nor do they explicitly discuss if a placebo effect exists, they merely assume it a priori). Cacycle (talk) 02:09, 9 November 2008 (UTC)
  • looie496, I too would like to see any significant studies that contradict their findings. -- Fyslee / talk 06:31, 10 November 2008 (UTC)
  • Cacycle, H & G do not deny the existence of the placebo effect. That's a serious misunderstanding. They only showed that all the existing literature up to that time revealed a misunderstanding and exaggeration of its effects. -- Fyslee / talk 06:31, 10 November 2008 (UTC)

I'm really puzzled by this discussion. Time after time I've seen it written that it essential to test new drugs or whatever using double-blind trials, so as to eliminate the placebo effect, and that positive results from other less careful trials were explained away for the same reason. Is it now being suggested that all that effort has been wasted, since the placebo effect doesn't exist? SamuelTheGhost (talk) 23:28, 8 November 2008 (UTC)

The problem is really the ambiguity of the terms placebo, placebo treatment, and placebo effect and the article intro does obviously not a good job at explaining this.
Every scientific experiment, including clinical studies, need control conditions that resemble the test condition as much as possible in order to be able to isolate and measure a single variable or effect. In clinical studies this control is usually called placebo treatment and differs only by the use of an inactive drug. This allows to keep the study design double blinded and thereby minimizes reporting as well as observing bias.
In order to measure the placebo effect, one has to compare a placebo treatment with no treatment at all, as most clinical conditions get better over time, an effect called regression toward the mean. Most clinical studies do not have such a third no-treatment arm. Hróbjartsson and Gotzsche have analyzed all available studies until 2004 that had a placebo treatment as well as a no-treatment group and found no evidence for a general placebo effect (i.e. the placebo treatment patients did not better than the no-treatment patients). The only exception was a very small (!) effect that was only seen for patient self-reported ratings, which is, as a matter of principle, indistinguishable from reporting bias as this part of the study is now unblinded.
Cacycle (talk) 01:23, 9 November 2008 (UTC)
Thanks very much for your prompt reply. I'm thinking about it. SamuelTheGhost (talk) 12:22, 9 November 2008 (UTC)
If a condition gets better over time, this has little to do with regression to the mean. The strongest effect is the ability of the body to heal itself. Another factor is the evolutionary tendency for infectious diseases not to progress to the point that they kill the host - they tend to move from host to host. And another factor is that patients who are given no medicine by their doctor will self-medicate - either with OTC medicines or with folk remedies. So, for example, if you have the common cold, you will get better in time because the virus lets itself be overwhelmed by your immune system. If your doctor gives you no medicine, then you will tend to take an OTC remedy or chicken soup/hot toddy. Colonel Warden (talk) 08:53, 12 November 2008 (UTC)
Could I also suggest that Cacycle has somehat misrepresented regression toward the mean? This occurs when two successive rather imprecise measurements are made on some attribute of a single element randomly drawn from a population. If the first measurement is well away from the population mean, the expected value of the second measurement will be nearer to that mean. In the case of patients with some chronic condition, it implies that if an assessment finds that a patient has a "bad day", later assessments are likely to show an improvement, whereas if the patient has a "good day", later assessment will show deterioration. The effect is symmetrical between getting better or worse, and only applies to the short term, or to populations with long-term stability, such as patients with chronic but not fatal conditions. It therefore does not mean "most clinical conditions get better over time". Colonel Warden has given convincing reasons why that might be so in the medium term. (In the very long term, all patients get worse and die, as I am sure we will all discover in due course.) SamuelTheGhost (talk) 17:07, 13 November 2008 (UTC)
In medicine, regression toward the mean is often cited in regard to chronic conditions. This paper has some more information and relevant examples. When it comes to placebo effects, the reality is that most patients seek treatment at the peak of a condition's negative symptomology: the highest point of a fever, the worst of the knee pain, the most depressive mood, etc. For example,

Trials of hormone replacement therapy show a strong placebo effect on menopausal symptoms. This implies that menopausal symptoms are susceptible to placebo treatment. However, a recent systematic review of placebo versus “open” no treatment found little evidence for the placebo effect. A more likely explanation is that the placebo effect is simply regression to the mean. Women recruited to trials of hormone replacement therapy typically score highly on a symptom index. Because the trialists are identifying women with relatively extreme menopausal symptoms, once treatment starts, improvement will occur in both the placebo and active treatment groups because of regression to the mean. An indication that regression to the mean is occurring is that patients with the worst clinical scores have the biggest placebo effect.

Thus, regression to the mean can contribute (even dominate) placebo responses because of this general nature to seek intervention near the acme of a disease or condition. Regression to the mean is not simply getting better over time--some of it is natural healing, especially in self-limiting conditions, but chronic hypertensives (for example) will regress towards their average hypertensive state following a peak in blood pressure; regression to the mean also includes the artificial selection of tested conditions as well: the perfectly healthy people on one end of SamuelTheGhost's symmetrical axis are rarely involved in medical interventions. — Scientizzle 22:00, 13 November 2008 (UTC)
I'm not sure this all makes sense. When somebody says "there is a strong placebo effect", the meaning is that there is a large difference between placebo and no-treatment. Wouldn't regression to the mean operate just as strongly in the no-treatment group?—Preceding unsigned comment added by Looie496 (talk • contribs)
I think you're mistaken about the meaning of "there is a strong placebo effect" in this case.
In the quote above, medical interventions for menopausal symptoms were compared to placebo only, and both offered improvement (whether hormone replacement therapy works better than placebo is beside the point in this case). Placebo compared to no intervention showed no strong effect (in Hrobjartsson & Gotzsche). Therfore, the authors argue, regression to the mean may plausibly explain much of the observed placebo response in hormone replacement therapy trials because the selection of drug-vs-placebo trial participants usually used subjects with symptoms towards one extreme end. If participants are selected from an extreme end of the symptomology spectrum, one can predict that the regression to the mean effects of all possible groups (treatment, placebo, or no treatment) will be pronounced; the effect should be diminished if subjects are drawn from more average symptomatics. — Scientizzle 23:52, 13 November 2008 (UTC)

It exists

Copied from above

I'm probably missing something here, since I haven't been following these discussions for some time, but if the article really suggests "that the placebo effect does not exist," (CW above) that needs to be changed. Where does the article say that, or is this a straw man? Saying that the very real placebo effect (Hróbjartsson and Gøtzsche don't deny its existence) is mainly a subjective effect, is not the same as saying that it doesn't exist. It's just saying that it has been misunderstood, and that its efficacy for creating objective effects on serious illnesses has been greatly exaggerated, and their metanalyses of all the literature showed that to be true. -- Fyslee / talk 06:33, 10 November 2008 (UTC)

This is the original edit. Verbal chat 07:19, 10 November 2008 (UTC)
Please see my long explanation right above this section. The article and the intro is currently a mess and does not make a good job at differentiating different uses of the discussed terms. It also somewhat misrepresented the results of the Hróbjartsson and Gøtzsche studies. I have added inline citations to the article and the first 2001 study is freely accessible:
Cacycle (talk) 13:59, 10 November 2008 (UTC)
Since this is obviously a contentious matter, and edit warring doesn't solve anything, may I suggest that any potentially controversial edits be proposed here first? Please avoid the WP:BRD cycle, which doesn't work well on controversial articles. You're welcome to start a new section and propose your suggested improvements there. Then, after all involved editors have commented on it, we can work together in a collaborative effort to create a satisfactory entry. Only then will consensus be working. For this to work, we all need to be very specific by pointing to exact wording and providing good sources. I'll add a references section below so this will work, just as we use on some other article talk pages.-- Fyslee / talk 15:09, 10 November 2008 (UTC)
Although this may considerably complicate matters . . . When will all of you fuzzy thinkers stop talking about a "placebo effect"; there never was, and never ever will be a "placebo effect" -- it was, is, and always will be a "placebo response". And, I am certain that all of you will continue to have this useless sort of debate until doomsday; simply due to the fact that there is no "placebo effect", there is only a "placebo response" -- and it is the existence of this "placebo response" that you are really debating about.Lindsay658 (talk) 02:39, 14 November 2008 (UTC)
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