The Power and Pitfalls of Omics: George Davey Smith’s storming talk at ME/CFS conference
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Diseases the placebo effect works for, and ones it doesn't work for (it's to do with dopamine)

Discussion in 'Other Health News and Research' started by Hip, Dec 12, 2016.

  1. Hip

    Hip Senior Member

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    One or two interesting points are made in the following article:

    Here's What Placebos Can Heal—And What They Can't

    The article is an interview with biologist Erik Vance about his book Suggestible You: The Curious Science of Your Brain’s Ability to Deceive, Transform, and Heal.



    Some excerpts from the article:



    So what Erik Vance seems to be saying is that the placebo effect involves dopaminergic effects, and so stands a good chance of working for diseases where dopamine is low, or for diseases where increasing dopamine may be helpful.
     
  2. hixxy

    hixxy Senior Member

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    I think my dopamine is low. Where's my placebo effect?
     
  3. Hip

    Hip Senior Member

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    In this post, I suggested that focusing on an imaginary but wonderful destiny may have serotonergic or dopaminergic effects in the brain that create disease-modifying effects, and this may explain why in rare cases, some ME/CFS patients say they have improved from therapies such as the Mickel Therapy and the Lightening Process.

    In short, the claimed improvements in ME/CFS from such therapies may come from using thoughts and the placebo effect to raise dopamine.
     
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  4. wdb

    wdb Senior Member

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    This was written in response to a different piece but I think it applies equally here.

    I don't think it is any coincidence that the conditions mentioned as responsive to placebo are all largely measured subjectively but cancer which is not responsice can be qualtified objectively.

    The Placebo Narrative
     
  5. Hip

    Hip Senior Member

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    Yes, that's always an issue in subjectively reported symptoms: are the symptoms actually better, or does your more positive mood just tend to mask them.
     
  6. Barry53

    Barry53 Senior Member

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    This has engineering equivalents where, if care is not taken, the very act of making a measurement can influence the value of what you are attempting to measure. e.g. When measuring a voltage, the voltmeter's internal impedance must be a lot higher than the circuit's impedance where you are measuring, else the voltage reduces simply by connecting the voltmeter; the voltage you read is therefore artificially low. This is just one example.
     
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  7. Hip

    Hip Senior Member

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    At least with ME/CFS, you have the 2-day CPET test which can objectively measure the energy metabolism dysfunction in ME/CFS patients, so using this test, it should be possible to figure out whether a dopamine-raising placebo response is merely masking the symptoms of ME/CFS, or whether that raised dopamine is somehow having system-wide disease modifying effects that show up as improvements on the 2-day CPET.
     
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  8. alex3619

    alex3619 Senior Member

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    We know that in asthma the use of CBT can produce subjective improvement, but no actual improvement as measured by objective tests. Most conditions have some objective tests that can be run, but those promoting the power of the mind, positive thinking, or CBT, tend (but not always) to scrupulously avoid objective evidence. It makes the entire field dubious.

    Having said that, as an hypothesis the idea that this is a dopaminergic phenomenon is something that is testable, and it would be interesting to see the data from objective measures relating to this in future studies.

    Let me presume for a moment the hypothesis is correct. Because of our severe metabolic problems it may be that a proper placebo response has modified reliability in us. We also have to consider that much of the time people, particularly those in psychotherapy, often work with what they think is happening, and not what is actually happening, and so the psychotherapy can bias their response to questions.

    Objective evidence. Period. I distrust subjective evidence in science.
     
  9. Hip

    Hip Senior Member

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    Dr Andrew Miller's ideas on how low dopamine may be responsible for an undesirable amplification of the effects of inflammation in the brain are interesting. To quote Cort's article:
     
  10. Snow Leopard

    Snow Leopard Hibernating

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    Sounds like neurobabble to me (as Neuroskeptic puts it). (When people make gross generalisations about neurotransmitters...)

    The placebo effect is simply distraction from one's symptoms (hence ticking different boxes on a questionnaire) - there is no magic healing going on due to the placebo effect.
     
  11. Hip

    Hip Senior Member

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    That's what they imply in the Wikipedia article about placebo effect:
    Although this study on Parkinson's found that the placebo effect led to objectively measurable improvements in motor symptoms in 16% of patients.
     
  12. duncan

    duncan Senior Member

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    The study title seems to claim placebos heal. Heal.

    It is one thing to suggest placebos might benefit in some way in some cases. It is altogether a different matter to declare placebos heal. Smacks of the recovery controversy.
     
  13. Sean

    Sean Senior Member

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    Uncontrolled generic confounding factors are most likely explanation for the vast majority of reported placebo effect.

    Also, the Hróbjartsson and Gøtzsche meta-analysis on placebo effect size was further updated in 2010, confirming the result from the two earlier versions of the analysis.

    https://www.ncbi.nlm.nih.gov/pubmed/20091554

    I think this is one of the most important (non-ME/CFS specific) papers for us to know about, because it places serious constraints on what can be claimed on the basis of placebo effect, and hence its inverse, the nocebo effect, which is one of the main justifications for psychogenic claims about ME/CFS.
     
  14. alex3619

    alex3619 Senior Member

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    Worth noting the Cochrane library has the full text for free.
     
  15. A.B.

    A.B. Senior Member

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    This appears to be a case of a misleading title. The investigators were not blinded to the treatment and assessed the motor function according to this scale http://www.etas.ee/wp-content/uploads/2013/10/updrs.pdf which is subjective.

    I haven't looked at the study they cite but it seems to be a standard RCT so there probably was no third control group that would allow comparison of placebo vs nothing.

    In conclusion, this looks more like the authors don't really know what they are doing rather than placebo having a real effect.
     
    Last edited: Dec 13, 2016
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  16. Skippa

    Skippa Senior Member

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    Just watched my FIL die of Parkinson's

    It's a slow, cruel disease. Slowly dying over a period of years. Took 2 weeks without food at the end to finally find peace. No amount of therapies or pills brought any kind of placebo relief to him.

    I am cynical.
     
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  17. Barry53

    Barry53 Senior Member

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    Which I am sure the PACE authors (being phsyciatrists and all that) were only too well aware of when they they opted for subjective outcomes instead of objective ones.
     
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  18. Hip

    Hip Senior Member

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    Can I ask where you read that the investigators were not blinded, because I just had a look at the full paper on SciHub, and it says:


    I found this other paper on the placebo effect in Parkinson's disease. Although it does not measure symptoms, it did find via a PET scan that there is a release of endogenous dopamine in the dorsal striatum in placebo-responsive patients:
     
  19. A.B.

    A.B. Senior Member

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    In the abstract they don't describe it as blinded, so I assumed it wasn't.

    I don't believe this changes anything. To evaluate the effectiveness of placebo, one would have to compare it to nothing.
     
  20. Hip

    Hip Senior Member

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    I believe they did. This 2001 paper appears to be the actual study. From the full paper on SciHub, they say:
    So this clearly shows an increase in dopamine release in the striatum as a result of the placebo effect.



    This study is interesting:
    Immediate placebo effect in Parkinson's disease--is the subjective relief accompanied by objective improvement?

    They concluded that:
     

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