mckenzievmd - 28 November 2012 03:22 PM

...As for the literature in animals, there is unquestionably a strong placebo effect, both direct and via proxy, evident in clinical trials, so despite the almost certain lack of beliefs about their condition, animals appear to respond to inert therapies at much the same rate human patients do. Here are a few examples:

Caregiver Placebo effects in dogs with osteoarthritis

Placebo effects in canine epilepsy trials

Malek S, Sample SJ, Schwartz Z, Nemke B, Jacobson PB, Cozzi EM, Schaefer SL, Bleedorn JA, Holzman G, Muir P. Effect of analgesic therapy on clinical outcome measures in a randomized controlled trial using client-owned dogs with hip osteoarthritis.
. BMC Vet Res. 2012 Oct 4;8(1):185. [Epub ahead of print]

Is there a placebo effect in animals?

I couldn’t access the canine epilepsy journal article. Does it show an “unquestionably strong (direct) placebo effect (in animals)” as you suggested? The first site, suggests a strong proxy effect which the author views as dangerous for animals.  The 3rd site said “there is little evidence that they (placebo effects) exist in animals”.

Mckenzie, your points are well taken. I’m not sure that I would really categorize all of those things as placebo effects. Regression to the mean and spontaneous resolution for example would occur even in subjects who were not given a placebo or any treatment at all. Strictly speaking a placebo effect should occur in subjects receiving a placebo but not be observed in an untreated group.

Some of the other examples may not appear to require faith in the benefit of the treatment but on closer inspection they do. The Hawthorne effect is may be mediated through belief in many cases since a patient who did not think they were in a potentially beneficial treatment program is not as likely to change other behaviors that would improve their success. I suppose some may alter their behavior simply because they are being observed but again this might be seen in subjects who were under observation and but not given any sort of treatment.

I may have not made my point clearly in my post above. I don’t think that skeptics are less likely to be susceptible to the placebo effect.  The sort of belief or faith we are talking about here is faith that the treatment you are being given is efficacious.  Faith is still faith whether its belief in total voodoo or faith in something thats just as useless but has a seemingly plausible scientific explanation.

I simply hypothesized that skeptics might be less likely to be “victims” if you will of the placebo effect in their daily lives because of their tendency to stick with science based treatments. This means on the whole they may find themselves in the position of taking useless treatments less often then non-skeptics. On the other hand I am sure that skeptics are “cured” of their cold or bronchitis with antibiotic treatments on regular basis when their physician incorrectly diagnoses it as a bacterial infection. Because it seems rational they have faith in it and the placebo effect will be similar to that seen in a non-skeptic.

TimB - 28 November 2012 05:26 PM

I couldn’t access the canine epilepsy journal article. Does it show an “unquestionably strong (direct) placebo effect (in animals)” as you suggested? The first site, suggests a strong proxy effect which the author views as dangerous for animals.  The 3rd site said “there is little evidence that they (placebo effects) exist in animals”.

The problem i see with the second study ( seizures) is that there isnt a good description of the methods in the abstract at least. It would be helpful to know how the seizure frequency was documented. If they were observed and recorded by owners then confirmation bias becomes a big issue since not every seizure is a full blown tonic clonic event and there is room for interpretation on the part of the owner. The researchers themselves are not immune to this either. There has to be a very objective way of determining what gets included in the seizure count and what doesnt.

BTW, I think that it was I who blithely threw out the comment that skeptics may be immune to placebo effect. Participation in this discussion with the thoughful input that has been provided, has helped me come to a better understanding of the possible mechanisms by which skeptics can interpret positive outcomes to the receipt of inert treatments.

Time,

Dr. Ramey’s comment that there is little evidence for a placebo effect in animals again is intended to refer to a perceived improvement in one’s own subjective symptoms derived from the belief that one is receiving an active treatment. As I pointed out above, this is the most commonly thought of form of non-specific treatment effects which create the false impression of efficacy for medical treatments, and it is likely not an effect experienced by animals since it is based on expectation and belief. However, as I tried to illustrate, there are many other effects which create the same false impression and which can be controlled for using a placebo arm in a clinical trial, and these often to affect animals as well as humans. So in this sense, some placebo effects affect animals and others do not.

As for the seizure study, seizure frequency is recorded by owners in these studies, as it is in the normal course of clinical management. There really isn’t another practical way to monitor this since EEG evaluation is rarely useful in veterinary patients for a variety of reasons. Undoubtedly, many seizures which are not tonic/clonic are missed by owners. This would generally tend to lead to an underestimate of seizure frequency. However, in a clinical trial with a treatment and a control arm, there isn’t a reason to think this source of error would be differential between the groups, so likely it would affect the absolute but not the relative frequency reported. In other words, the fact that clients report a decrease in seizure frequency in both treatment and placebo groups indicates that seizures are either truly lower for reasons having to do with participation in the trial other than the efficacy of the drugs, or that participation in the trial leads to a perception of fewer seizures in owners due to caregiver placebo effects. Likely, both are true. Owners in a clinical trial likely comply better with concurrent therapy, and pets are monitored more closely and their therapy adjusted as needed more often than pets not involved in a trial. And likely people perceive improvement even when it isn’t real as a result of expectation, belief, and ther other sources of error I talked about. All of this illustrates that many of the sources of error we call placebo effects do exist when evaluating the efficacy of therapies in animals, and that placebo controls are necessary to establish true efficacy in animals even if they don’t have beliefs or expectations themselves.

Mac,

I agree that skeptics in general are less likely to try unproven or unscientific therapies, so in that sense they may be less likely to develop false beliefs in the efficacy of such treatments as a result of placebo effects. But if skeptics are induced to try such therapies, in order to prove they are open-minded, out of desperation, or for whatever other reason, I think they are just as likely as people who don’t think of themselves as skeptics to end up with an inaccurate assessment of the efficacy of the treatments, and for all the same reasons. So many of the testimonials for BS therapies begin with the assertion that “I was skeptical at first…” followed by compelling but meaningless anecdotes. So I think we agree, but I just can’t help but emphasize as often as possible that none of us are immune to the errors or judgment that science exists to compensate for.

Latest Read- Thinking Fast, Thinking Slow by Daniel Kahneman

This one summarizes brilliantly the psychology research supporting the need for deep and serious skepticism about our own judgments as much, or more, than those of others.

mckenzievmd - 28 November 2012 06:53 PM

... In other words, the fact that clients report a decrease in seizure frequency in both treatment and placebo groups indicates that seizures are either truly lower for reasons having to do with participation in the trial other than the efficacy of the drugs, or that participation in the trial leads to a perception of fewer seizures in owners due to caregiver placebo effects.  Likely, both are true. Owners in a clinical trial likely comply better with concurrent therapy, and pets are monitored more closely and their therapy adjusted as needed more often than pets not involved in a trial…
.

I think it follows that a perception of fewer seizures by the owners is not necessarily indicative of a real effect for the animals. (One way to sort this out would be to have objective inter-rater measures.)  And if simply participating in the trials has a treament effect beyond what the drugs would have, I would be curious about the extraneous variables involved in particpating in the trial.

And, although I think you are making a decent case that the statement “Animals can benefit from placebo effects” is technically correct,  I also think that the statement is fraught with dangers of misinterpretation by laypersons.

Mac, I can’t get the exact research, but I have the basics of it.  (I won’t cover the animal side, since Mckenzie has pretty much already done so.)  Anyway, I think I got a bit ahead of my self as it seems that similar to animals, the placebo effect works in babies primarily through a combination of conditioning and the simple fact that increased human contact has a positive effect on them.  If I can pull up the damn data I will, but so far every link to it I try is dead or loads a blank page.  Lousy internet.

Anyway, from what I’ve read, I think expectation would be a more accurate word in relation to placebos than faith.  At the very least, it causes fewer misunderstandings and semantical problems.

Tim,

I agree there is plenty of room for misunderstanding, and in fact I think there is already a lot of confusion about what the placebo effect means. However, one consequence to claiming that there is no placebo effect in animals is that promoters of bogus therapies can say that if something “works” in animals, it must have real effects. Unfortunately, by “works” they usually mean that it appears to have an effect in trials without placebo controls or in general use by animal owners. This incorrect appearance of a benefit is the result of failure to control for sources of error that are generally controlled for in proper clinical trials by randomization, blinding and, of course, a placebo control group. So as usual the issue is complex. The important part is not so much whether placebo effects exist in animals, since the answer to that depends on how one defines palcebo effects (only belief and expectancy, including conditioning, non-specific trial effects, etc). What is important is that we recognize that there many of the sources of error in our attempts to evaluate medical therapies besides belief/expectancy/credulity, and that whether you’re a devout theist, a committed skeptic, or a golden retriever, your use of a medical therapy without proper controlled evaluation is likely to lead to the wrong conclusion about whether or not it works.

True.  I also think that it would be nice to have a clear standardized definition of “placebo effects” that precludes people from thinking of it as some sort of magical variable.

TimB - 29 November 2012 02:55 PM

True.  I also think that it would be nice to have a clear standardized definition of “placebo effects” that precludes people from thinking of it as some sort of magical variable.

Thanks Tim for directing me to this thread that I’ve missed due to me hating anything Alternative Med.

Macgyver wrote

I may have not made my point clearly in my post above.
I don’t think that skeptics are less likely to be susceptible to the placebo effect. 
The sort of belief or faith we are talking about here is faith that the treatment
you are being given is efficacious. 
Faith is still faith whether its belief in total voodoo or faith in something
thats just as useless but has a seemingly plausible scientific explanation.

I agree to that we need to know what we talk about. Definition of placebo.

One big problem for study this is the self reporting of the “Patient”.
I am very skeptical to that we are good at such even among us skeptics.

A lot of those that look at the Zeitgeist Movie write in forums them are
atheists and skeptics and still they believe in Truther conspiracy ideas
so it seems complicated indeed. The ironic thing is that Sam Harris who
surely see himself as very skeptical to organized religion he did in his
first book recommend people like Rupert Sheldrake and Dean Radin
and their ideas about Paranormal abilities among humans like Remote Viewing
and Morphological Fields so all of us are vulnerable to our own outlook?

Okay back to the theme. I tried to find out if I am good at being self hypnotized
because I see that as one indicator on if I can be receptive to the expectations
of Placebo. I where very lousy at self hypnosis due to my inability to concentrate
I am too ADD/ADHD to be able to stay focus for more than a few seconds.

But I seem to be receptive to persuations. Them being just short words like
Try this! ... I tested something they named Balancing the Body Energy Field
or similar name. Popular way back in 1970 or so. They manipulate the muscles
in arm or leg and that worked too well I get really scared how effective it was.

The muscles did what the Manipulator told them to. Feeling weak when tasting
sugar and strong when tasting Carrot juice. Haha I hated them for their skills
manipulating me against my conscious will.

So sure I trust that Placebo really do work if the person giving it is skilled enough
to perform something that the body get fooled by bypassing the conscious resistance to it.

Another good example from about 1985? I longed for a group to express my
naturalistic religious feelings and let me be persuade to see if I could cheat
pretending to be a Christian and pass as one among them and not get caught.

Heheh I had to run out of the Church because they where so good at setting up
the persuasion that my body showed that it would convert me against my will
if I did not run out of it and to distract it with looking at traffic and heading home.

The feeling of love for Jesus where so strong that I would ahve given in there
if I had not run out. The funny thing is that I had taken off my shoes so I had
to run having them in my hands. Must have looked really funny a guy running
down the pew with shoes in his hands instead on his feet
Anyway I am still atheist but my body remember how it felt and it tells me
that it want more of that experience again. A kind of dependence built up
despite only one instance of induced use. High on Jesus. And I am absolutely
against all drug use have never even used alco apart from an experiment
that lasted 10 minutes using 6CC alco on 300CC water? One drink?

The best experience in my whole life. The only time that I felt normal ever.

So I hope you guys get motivated that we do this together. Find good definition
of what goes on in Placebo.

1. Placebo is about expectation of an effective treatment for something one want a cure.
2. The one that give the Placebo need to give the impression them trust in the effectiveness.
3. If the Placebo treatment is a physical manipulation it needs to appear reasonable to the Patient?

Just my hasty set up I am a naive thinker but I am really interested in Placebo
after reading this.
http://www.smh.com.au/lifestyle/diet-and-fitness/why-placebos-may-work—even-if-patients-know-theyre-fake-20101223-195w3.html

“Not only did we make it absolutely clear
that these pills had no active ingredient
and were made from inert substances,
but we actually had ‘placebo’ printed on the bottle,”
Associate Professor Kaptchuk said in a statement.

“We told the patients they didn’t have to even believe in
the placebo effect – just take the pills.”

So we have two factors here. The willingness of the patient
to go along with the experiment. I come to think of Stanley Milgram
that such “authority effect” can creep in. It is a kind of Teacher/Student
relation or Doctor/Patient relation or even Parent/Child relation of trust?

Humans being hierarchical and good at “Follow John Games” where one
Go with the Flow and does not oppose but play along effect.

Then the expectations that one are doing break through science?
One don’t expect that it really will work but one are motivated to try
for to eliminate what one already find incredible and to everybody’s surprise
it worked so more research is needed and this was two years ago so ...

I mean one don’t have to be scientists to do such experiments.
I tested if it would help me to put trust in Amida Buddha and it worked
to a certain degree. I had to translate into naturalistic setting what they
had in myth words and I failed to go along with their culture but apart from that
it worked rather well. So to me all this is very interesting.