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Placebo effect revisited

Hi all,

This is a good article written by Dr Steve Novella on the placebo effect. It’s definitely worth a read.

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Existing evidence strongly suggests that placebo effects are mostly comprised of bias in reporting and observation and non-specific effects. There is no measurable physiological benefit from placebo interventions for any objective outcome. There is a measured benefit for some subjective outcomes (mostly pain, nausea, asthma, and phobias), but the wide variation in effect size suggests this is due to trial design (and therefore bias) rather than a real effect.

In any case, any perceived benefit in subjective symptoms seems to be greater for physical interventions (perhaps a hands-on benefit) but is the same for mainstream vs novel treatments.

Therefore, there is no justification to be found in the placebo effect for using unscientific or dubious interventions. Placebo medicine is a sham. And any potential placebo benefit worth having can be fully realized with science-based interventions.

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http://www.sciencebasedmedicine.org/?p=4304

Scott 8)

And another article in the news on this today. Fascinating stuff for anyone interested:

theaustralian.com.au/news/he … 5845575117

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“Many parts of the therapeutic process, such as visiting the doctor and discussing our symptoms, represent an important part of treatment, just like the drug we may later collect from the pharmacy.”

He claims many factors interact for each patient. These can be past experience, expectation and desire to recover. They can be the doctor’s charisma, communication skills and empathy, as well as doctor-patient interactions and the act of giving a pill or injection.

But just as this mind-body interaction can have positive results, the reverse can also happen. The “nocebo effect” is when a person has or is given negative expectations of a drug or treatment with results as powerful as placebo.

A 2006 study by Finniss and Benedetti’s Lancet co-author, Ted Kaptchuk of Harvard University, found that patients who received a dummy acupuncture needle that didn’t penetrate the skin experienced a red rash where the dummy needle was applied, after being told that a rash could be a treatment side effect. Something as simple as a doctor saying “This might hurt a bit” could worsen pain experienced through the nocebo effect. As Finniss says: “Words are very powerful, but they are only one component of what is a very complex therapeutic context.”

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Excellent links and very interesting. Thanks Scott.

Scott, I believe that his conclusion is overstated, based on the summation he himself presents. Similarly, Hróbjartsson and Gøtzsche’s review, which he quotes, does not lend itself to as blanket a condemnation as a non-technical interpretation of the words might suggest.

Here are the issues:

When performing a meta-analysis, an analysis spanning numerous studies, one basically excludes studies (albeit not necessarily without acknowledging the fact) that are too flawed for inclusion in quantitative comparisons. The piece reported that the placebo effects found ranged from negligible to clinically significant. This must mean that some were indeed found to affect physiological markers as well as subjective reports. (N.B. My impression is that if there is any modification of subjective report that appears to be unaccompanied by physiological change, it is because the physiological changes accompanying it were not deemed to be of interest–perhaps a valid perception.)

When I say in casual speech, “She’s showing bias,” I mean she’s a prejudiced judge in some realm, unwilling to look at what’s in front of her. When I say that a scientific study or series of studies betray bias, I mean something far more specific. One of two things, actually. Sometimes I may say there’s systematic bias, another particular factor that should have been accounted for. For instance, classically, I might find that certain heritable racial characteristics correlate with early death. If I don’t account for the fact that in a particular country race is accompanied by many other characteristics, my data are a hell of a lot less useful than if I account for confounding elements that would bias the findings, such as social class and income.

Other times, I may say that study outcomes appear biased, and what I mean is that the outcomes are not a nice clean demonstration, showing the same consistent pattern of effect(s). There are many possible reasons for this, but one of the most common ones is that I don’t have a good way to either control the factors that affect the outcomes, or measure the pesky ones and thus control their effects in my data analysis.

An intuitive example is psychotherapy. A single talk therapy has been manualized well enough that it could be formally studied and proven to be effective, as effective in treating many depressions as medication regimes. This is cognitive-behavioral work, which I think of as straightforward elicitation and reframing of internal verbal patterns. Formalized and manualized or not, its effectiveness still varies with the practitioner. However, efforts to specify the differences between more- and less-effective cognitive-behavioral therapists have been of limited value. non-specific bias, or noise in the data set, from one perspective.

But even beyond this data set, what does it mean that this is the only approach studied well enough that its manualization could be demonstrated to work? It means that other approaches are messier, not that all the seeming results from their use in some of the more-rigorous peer-reviewed journals are actually artifacts of the passage of time (and money).

I’ve always been fascinated by placebos and the placebo effect so this article I found amazingly interesting though still not quite sure how we MAVers could fully utilise its potential. Though with our trial n error drug strategy maybe … can’t quite imagine the ‘Hi Doctor could I try some red ones next please?’ Would work. Not in my neck of the woods. Helen

I think I must be completely immune to the placebo effect. Or maybe that doctor knows best thing has proven itself a sham way too many times in my life. I’ve had doctors hand me scripts with total confidence and yet the drugs they prescribed have not cured me or failed to provide significant, debilitating side effects. I think if you’ve fallen far enough down the rabbit hole you begin to see the illusions for what they are.

It’s sad how life’s experience leaves us cynical but it just does. I’m a firm believer ‘Ignorance is bliss’. Trouble is we can’t turn the clock back and unlearn it can we. Lack of success isn’t forgotten. I look back to when I first started taking the Propranolol. I’d been delighted, after years of being told there was no available treatment, to discover somebody who seemed to know what was wrong with me and that preventatives existed. In totally blissful ignorance I couldn’t wait yo try some assuming they would work and would work quickly, certainly within weeks. I had no concept of adverse side effects, being totally unable to tolerate them or having to wait half a year for slight improvement. I was diagnosed mid October and expected to be better by Christmas. I’m sure I did. That ignorance lasted many more months mainly because of the visual stuff I was off screens and the internet indeed still living almost in darkness like the proverbial mole, and it did me no harm whatsoever. In fact it made my life simpler. These tablets were going to work. Bound to. After all why wouldn’t they. In actual fact they took an age to kick in for most symptoms so their ‘placebo’ effect wasn’t that strong but I suppose the sustained illusion proved helpful in that I stuck with it if only because I had no idea Where else to go. Helen

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There is a podcast called “Hidden Brain” and one episode was about placebos. It was VERY interesting. Here is the transcript from that episode:
https://www.npr.org/templates/transcript/transcript.php?storyId=718227789

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Huge thanks for sharing.

You’re welcome! I think the part that surprised me the most was that even when they told one woman that the pill she was taking was a placebo, she swore it worked and wanted to continue taking it.

Oh. Never under-estimate the power of The Mind. It’s amazing. I feel if more attention was paid to the psychological effects of the fallout from MAV a lot of people would benefit. Here in the UK it is just totally ignored. Not suggesting anxiety is a cause of MAV for one minute but the lack of ability of the medical profession to diagnose and treat extends the condition and causes further problems.

Only a weak example it may be but I remember how I stuck with Propranolol for many months with very little sign they were relieving anything. I never thought to quit or change. In blissful ignorance I didn’t know there could even be a possibility that they wouldn’t work. I’d been told to take ‘preventatives’ and I just expected them to ‘prevent’. I didn’t appreciate alternatives even existed. I just kept waiting. Nobody’d ever sewed a seed of doubt. In some ways it’s a shame innocence lost can never be regained. It was all in the mind. Helen