[HN Gopher] Why do placebos work? Scientists identify key brain ...
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Why do placebos work? Scientists identify key brain pathway
Author : pseudolus
Score : 141 points
Date : 2021-10-28 10:41 UTC (12 hours ago)
(HTM) web link (www.science.org)
(TXT) w3m dump (www.science.org)
| podiki wrote:
| While I always thought placebo (and nocebo) is quite amazing,
| I've had that tempered from some reading of it perhaps not being
| a large effect beyond a regression to the mean. For example,
| here's one paper [0], with a quote from the abstract "Analysis of
| the trial outcomes demonstrated that the reduction observed in
| the placebo group was of the same magnitude as predicted by
| regression to the mean."
|
| Or from [1] in their summary: "In clinical practice, the
| phenomenon [regression to the mean] can lead to misinterpretation
| of results of tests, new treatments, and the placebo effect"
|
| This has been discussed in some popular sources as well, like the
| fun book The Math of Life and Death by Kit Yates.
|
| [0] https://pubmed.ncbi.nlm.nih.gov/15975061/
|
| [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1125994/
|
| Edit: see also this helpful explanation elsewhere in the comments
| [2]. The thread there highlights this paper [3] with the key
| conclusion of "There was no evidence that placebo interventions
| in general have clinically important effects. A possible moderate
| effect on subjective continuous outcomes, especially pain, could
| not be clearly distinguished from bias."
|
| [2] https://news.ycombinator.com/item?id=29025886
|
| [3] https://pubmed.ncbi.nlm.nih.gov/12535498/
| Pyramus wrote:
| A couple of comments (not a medical expert):
|
| It's likely that the placebo/nocebo effect is confounded by
| regression to the mean - a typical example are diseases with
| some sort of cyclical pattern, e.g. some forms of depression.
|
| But there is strong evidence that there is an effect beyond
| that: E.g. cancer patients die significantly sooner when they
| get a negative prognosis [1]. Acupuncture is so effective for
| treating certain forms of chronic (!) pain that in some cases
| it's covered by German health insurance since 2007 [2]. If you
| have been treated in a hospital for pain related issues, e.g.
| after a surgery, it's not unlikely you have received placebo
| instead of pain killers (depends a lot on jurisdiction).
|
| Regarding [3] specifically, the obvious elephant in the room is
| that 'absence of evidence is not evidence of absence'. Also see
| the refutations pointed out by user PaulDavisThe1st [4]. What I
| take away from that study is that yes, in some contexts,
| regression to the mean may account for a major portion of the
| placebo effect.
|
| [1] https://doi.org/10.1016/S0140-6736(73)91754-6
|
| [2] https://www.verbraucherzentrale.de/wissen/gesundheit-
| pflege/...
|
| [3] https://pubmed.ncbi.nlm.nih.gov/12535498/
|
| [4] https://news.ycombinator.com/item?id=29028133
| podiki wrote:
| Good points, and I didn't mean to say that there isn't some
| placebo/nocebo effect. There's lots of evidence for the
| connection between mind and body, so it certainly seems
| plausible this happens (also not a medical expert).
|
| I've always found the placebo effect fascinating, but does
| seem, at least in popular coverage?, to be puffed up more
| when there's a lot we don't know. And of course it can be
| very hard to untangle when some people will just get or feel
| better for who knows what reason. Medical and human research
| can be very messy, much as the physicist in me just wants to
| see the hard stats showing a strong (causal) relationship.
| vlovich123 wrote:
| Is there any research into the variation of susceptibility to
| placebos? My gut feeling is that there are people who are much
| more susceptible and those who are much less, and I'm curious if
| that's supported by any research and, if so, how that difference
| is developed.
|
| Also, I'm confused by the conclusion of the article. If they're
| literally exciting or dampening a control pathway in the brain
| that controls pain, how is this placebo/nocebo? Sounds like a
| straight up causal effect, not a vague one controlled by the
| patient's expectation....
| cariaso wrote:
| yes
|
| https://www.snpedia.com/index.php/Rs4680
|
| and the others mentioned at
|
| https://www.snpedia.com/index.php/Placebo
| mathattack wrote:
| Call me a pedant but it kills me when these are done on such a
| small sample size. (27 participants)
| wolverine876 wrote:
| Volunteer for studies?
| mdp2021 wrote:
| If that were the problem, improve recruitment.
| wolverine876 wrote:
| Based on limited conversation with researchers, they are
| constrained by budget for experimental subjects and other
| resources (equipment, drugs, staff, etc.).
| tantalor wrote:
| Seems strange they would use petroleum jelly which is a well
| known treatment for burns. It is not a placebo; it's not inert
| like sugar pill or saline. This could seriously skew the results
| towards "pain relief" end of spectrum.
| dcow wrote:
| It's a moisturizer that treats water loss and protects skin in
| the presence of real burns. It doesn't do anything to pain.
| These people weren't burned. And I think Lubaderm is more
| commonly "well known" these days.
| dr-detroit wrote:
| More like why does anybody think chemical treatments are so
| effective when the studies are totally crooked? The placebo
| effect is just reality correcting the numbers for you.
| wolverine876 wrote:
| I would love to see a thread of people describing their own
| placebo responses, but one difficult part of understanding the
| response is that few people will admit to it.
| captainmuon wrote:
| I've never understood placebos. Naively you'd assume they work
| the other way around, as the body attempts to achive homeostatis.
| So if you think you have taken a pain killer, the body would ramp
| up pain sensitivity to counter it. But as far as I know a lot of
| studies have shown placebos work.
|
| One thing I haven't seen discussed is that maybe there is a
| subconcious social pressure element to placebos. Like: I just got
| a big injection from the doctor, surely it is going to help, I
| can't complain yet again about it. Sometimes I wonder, what if
| people take a placebo, report that they feel better, but continue
| to suffer internally? And are not even able to identify this,
| because their internal pain gauge is affected by the placebo.
| They think it helps. Maybe you could detect this by non-voluntary
| indicators of pain - avoidance reflexes, concentration loss,
| etc..
|
| Back to the homeostatis argument, there are placebo-like effects
| that _accidentially_ work. In autogenic training, you can warm up
| your body parts by imagining fire. What I think happens is, the
| body anticipates heat, widens the blood vessels to regulate
| against the heat, but in the cold environment this actually warms
| up your arms or legs.
| locallost wrote:
| There is a lot to how you perceive something that influences
| how you will react to what's going on.
|
| I was just today thinking about the difference between how both
| my children were born. There were so similar in the time they
| happened, how they were late, how the birth was triggered etc.
| But in the first case we were picked up by an emergency vehicle
| (there was no emergency, they just told us to do this), so it
| was dark, with this scary blue light as if somebody is dying,
| to some hectic in the hospital. And in the second we went very
| quietly to our appointment, rode the bus on a sunny day, took a
| relaxing walk outside the hospital as we were waiting etc.
|
| When it was done with the first, my wife was pale and
| shivering, completely out of everything, and with the second
| she was just exhausted but could still smile and enjoy taking
| our newborn. And she looked happy.
|
| Of course there is the case of the first being more scary
| because of the unknowns, but you could also make a case that it
| was so traumatic that it should've ruined the second one.
|
| I also fell down on ice once and had a case of whiplash. I got
| worried as I was reading about the potential long term,
| especially in the US. And I then switched to the German
| Wikipedia that said doctors in Germany tell patients to relax
| for a few days and it will go away, and that long term issues
| are virtually unknown.
|
| You could go on and on really. When you go to a doctor and they
| have almost no time for you, you will not feel better. Compare
| that with going in to somebody doing homeopathy. A friend told
| me they went and got a cup of tea and an hour to talk about
| their health issues.
|
| So the body is obviously complicated.
| pygy_ wrote:
| For social species, when resources are limited, evolution
| favors groups whose rejected members fall sick and die.
|
| The placebo effect comes from social support and goes beyond
| pain.
|
| As for the implementation details, expectations play a role. A
| drug that modulates the cholecystokinin neurotransmission in
| the brain (involved in expectation processing) was found to
| enhance the placebo effect of a placebo pill (on mobile, can't
| search right now, but with " cholecystokinin" and "placebo" you
| should find the paper on google scholar).
| jagraff wrote:
| > evolution favors groups whose rejected members fall sick
| and die.
|
| Do you have a source on this? I don't understand how
| evolution could favor such a negative trait on the individual
| level, and as far as I understand group selection has been
| mostly rejected by modern evolutionary biologists
| notshift wrote:
| It's true that some reject the idea of group selection, but
| there are lots of scientists too who embrace the idea. Lots
| of very good talks/interviews on YouTube with scientists &
| researchers on the subject.
|
| IMO there are too many phenomena that are very difficult to
| explain only with individual selection, but trivial to
| explain with group selection.
|
| Not sure about the claim that evolution favors groups whose
| rejected members die (not sure what rejected even means in
| this context), seems to me like that would depend a lot on
| environmental context and vary across species and across
| time.
| Pyramus wrote:
| > IMO there are too many phenomena that are very
| difficult to explain only with individual selection, but
| trivial to explain with group selection.
|
| Homosexuality is an obvious example that comes to mind.
| If you know others please do post them.
| DenisM wrote:
| Background for other readers:
| https://en.wikipedia.org/wiki/Group_selection#Criticism
| coolso wrote:
| > group selection has been mostly rejected by modern
| evolutionary biologists
|
| Not all things rejected by modern science is rejected for
| scientific reasons, unfortunately.
| pygy_ wrote:
| Putting it another way: there's a well established link
| between health and social status in social species.
|
| Group selection looks like the most logical explanation to
| me.
| jagraff wrote:
| It seems to me that you have cause and effect backwards.
| I think the most likely chain of events is something like
| this:
|
| Member gets sick
|
| Member gets rejected from the group (because for each
| individual in the group, it's better to avoid the sick
| member - no group selection necessary)
|
| Member dies
|
| So the member doesn't get sick because they're rejected -
| they get rejected because they are sick. This would have
| obvious benefits for each individual that rejects the
| sick member, regardless of the behavior of the rest of
| the group (https://esajournals.onlinelibrary.wiley.com/do
| i/abs/10.2307/...)
| bumby wrote:
| Could you explain that link between health and status a
| bit more?
|
| I vaguely remember reading adverse health outcomes in
| lower status individuals may be linked to the chronic
| stress attributed to being low status, but can't remember
| the exact source but this one came up in a quick search:
|
| https://www.sciencedirect.com/science/article/pii/S235228
| 951...
| oehpr wrote:
| I'd never thought about placebo's being a social mechanism.
|
| As a bit of a tangent, one of things I've always wondered is
| "how much pain do animals feel compared to humans?" The null
| hypothesis here would be that they feel the same amount, of
| course. On the other hand, what's an animal going to do with
| joint pain? Humans are unique in our ability to perform
| interventions. Suppose two people have cancer, one shows
| symptoms and one does not. A tumor can be excised before it
| becomes malignant. One would live and the other would die. Is
| there a pressure on us to have pain so that we can seek
| treatment?
|
| To bring this around to your comment. I wonder if we've
| demonstrated placebo effects on animals. That seems like an
| awfully hard study to conduct.
| iamcurious wrote:
| You are onto something factoring social pressure. Social
| pressure has a direction, if a doctor says you are going to get
| better it is creating a pressure on yourself to get better. In
| many cases that pressure might be all you need.
|
| The homeostasis effect might happen in an adversial situation.
| Say instead of a doctor, an opponent says something. It might
| cause to overcompensate in the opposite way. We could call that
| reverse placebo or by its more common name "spite".
| notjosh wrote:
| I think my favourite simple example to illustrate this is
| thinking of (or image searching a picture of) a lemon. A lot of
| people can feel increased saliva production under their tongue,
| despite nothing at all actually changing, in anticipation of
| the sourness. Brains are magical :)
| m3kw9 wrote:
| Psychological effect can amplify the pain you are experiencing.
| By really noticing and associating the pain with something worse
| than it is, it makes it hurt more. Placebo can take your mind off
| it and make it less noticeable.
| andrewon wrote:
| That reminds me of the idea that brain as a predictive engine
| that constantly refine its internal model to match anticipated
| sensory outcome. In this case the inference is way more complex
| based on cognition that the placebo would help relieve pain.
|
| Based on this idea, however, the study does not identify the key
| pathway responsible for placebo effect, but only the result of
| it. If the brain anticipate relief of pain, the parts related to
| pain would activate. If it anticipates other effects, other parts
| of the brain would do.
| gfody wrote:
| the predictive processing model, the best introduction to it
| imo is this review of "surfing uncertainty" -
| https://slatestarcodex.com/2017/09/05/book-review-surfing-un...
|
| _> 7. The Placebo Effect. We hear a lot about "pain gating" in
| the spine, but the PP model does a good job of explaining what
| this is: adjusting pain based on top-down priors. If you
| believe you should be in pain, the brain will use that as a
| filter to interpret ambiguous low-precision pain signals. If
| you believe you shouldn't, the brain will be more likely to
| assume ambiguous low-precision pain signals are a mistake. So
| if you take a pill that doctors assure you will cure your pain,
| then your lower layers are more likely to interpret pain
| signals as noise, "cook the books" and prevent them from
| reaching your consciousness._
|
| _> Psychosomatic pain is the opposite of this; see Section
| 7.10 of the book for a fuller explanation._
| rtkaratekid wrote:
| If the brain anticipates relief from pain, wouldn't the parts
| of the brain relates to pain be depressed rather than
| activated?
| refurb wrote:
| Think further downstream, beyond the pain sensing part of the
| brain.
|
| So opioids are know to be great pain relievers. What is
| interesting is for certain types of pain, they don't actually
| make the pain go away, they just change the perception and
| emotional response to it.
|
| Patients who receive opioids say "i can still feel the pain,
| but it doesn't bother me now".
|
| So to your question, the impact of opioids isn't necessarily
| on the pain sensing centers but rather further downstream in
| terms of how those sensations are perceived.
|
| If you take a placebo and expect it to relieve pain, your
| brain adjusts to assume that outcome.
|
| It's not that different than asking you if you're tired right
| now. If you have to go to work you might say "yes", but if
| you're about to jump on a plane for a vacation you might say
| "no".
| grp000 wrote:
| The simple explanation is that humans are 40K orks.
| archibaldJ wrote:
| Could perhaps be about reducing the cost structure of forming
| connections in the pathway while increasing in some, and thus
| more likely that some connections are formed/deformed (ie
| without the actual presence of agonists/antagonists)?
| WORMS_EAT_WORMS wrote:
| Super interesting comment and thoughts. Thanks for sharing - I
| never thought of it this way.
| nefitty wrote:
| My likely oversimplified understanding of dopamine is that the
| brain is constantly simulating the outcomes of possible
| actions. Simulated actions that result in "success" states
| generate dopamine, with different pathways generating varying
| levels at any one time. The pathway that generates the greatest
| net dopamine is pursued, the realized outcome of which then
| reinforces/dampens the path's simulation function by generating
| other neurotransmitters.
| richardatlarge wrote:
| an example of the complexity of dopamine: a study allowed
| animals to self-administer cocaine. Other animals were
| administered the drug in the brain on the same schedule but
| without 'choosing' to take it. The findings showed that the
| areas of the brain affected differed depending on these two
| conditions. This is a study with rats, and yet the effects of
| a seemingly small environmental/psychological difference
| changed everything
|
| Another study on electrical brain stimulation showed that
| while animals would self-administer it, when it was
| automatically administered, the same animals would respond
| always to turn it off
| MrBuddyCasino wrote:
| > brain as a predictive engine that constantly refine its
| internal model
|
| And a pretty effective one at that. Stereotype accuracy is one
| of the most solid and replicable findings in psychology. There
| are very strong correlations between what people think is true
| about statistical discrepancies between groups and what the
| truth actually is. The relationships consistently replicate and
| are much stronger than most effects found in social psychology
| [0].
|
| We must thus understand wokeism as a war on pattern
| recognition.
|
| [0] https://cspicenter.org/reports/the-accuracy-of-
| stereotypes-d...
| wolverine876 wrote:
| Prejudice is a serious problem - the most serious one. The
| horrors it has inflicted on people are a long catalog, maybe
| the worst one. What do you hope to achieve by supporting it?
|
| The underlying issue is about reactionary politics, which
| exists only to stop progress. I think if we look deep down,
| we know reactionary politics will object no matter what the
| issue or facts - therefore the objection has nothing to do
| with the question at hand or its outcomes. You can see it in
| climate change denial, as a simpler example. That is its
| purpose and reason - to object. Along the way, lots and lots
| of people will die and suffer. Blood, lost generations, are
| on our hands. And for what?
| MrBuddyCasino wrote:
| > Prejudice is a serious problem - the most serious one.
|
| I take it you have studied all the serious problems, so
| that you could come to the conclusion that this is indeed
| the most pressing one. Investing many years into studying
| human nature, the rise and decline of ancient civilisations
| plus the majority of philosophy is admirable! You don't
| happen to have written down any notes?
| coolso wrote:
| Prejudice is also why we're all here today, it has very
| well documented implications when it comes to survival
| among other things.
|
| Ignoring and censoring the truth because it's mean can be
| far more dangerous with far more disastrous effects.
|
| Censorship of thoughts is not the way to go - and the
| pushback, if it stays that way, is going to be worse than
| we can probably imagine right now.
| wolverine876 wrote:
| These are baseless assertions, absurd on their face,
| supporting hate. Why is that important to you? If you
| think you are fighting a political war, avoid the mistake
| that many before you have made - becoming so caught up in
| the mob dynamics, the cause, the obsession - that you
| disregard the consequences. Don't say later, 'I didn't
| think' - that's fine for a night out, but it's not good
| enough when people's lives and welfare is at stake.
|
| Everyone faces prejudices from some others; should
| everyone act on them? What kind of society will we have?
| On a practical level, how does that bring freedom and
| economic opportunity.
|
| You have a great model that has been far more successful
| than anything in the history of humanity, the free world,
| based on universal human rights and equality. The
| (general) lack of prejudice where I live works
| wonderfully; the bigotry - almost always from outsiders
| who have no experience with the people they hate - is the
| only problem. If they all went away, we'd have one less
| problem.
| coolso wrote:
| > supporting hate
|
| That is a bold, unfounded, unappreciated accusation. I do
| not support hate. I support gut feelings borne in truth.
| I will continue to not give free car rides to homeless
| people and to offer to help carry groceries out to the
| cars of little old ladies in front of me in line at the
| grocery store - because yes, stereotypically, the
| homeless are more likely to be drug addicts, mentally
| unstable, and have a criminal record, and little old
| ladies are more likely to need assistance carrying
| things. I don't hate homeless people nor do I hate little
| old ladies or consider them inferior. But please, feel
| free hire someone with face tattoos to be your child's
| bus driver in the interest of ignoring all prejudice at
| all costs. The rest of us will continue to make decisions
| using common sense, regardless of what Twitter has to say
| about the matter.
|
| > The (general) lack of prejudice where I live works
| wonderfully; the bigotry - almost always from outsiders
| who have no experience with the people they hate - is the
| only problem. If they all went away, we'd have one less
| problem.
|
| Could it be you're wrongly conflating prejudice with
| hate? Don't discount peoples' life experiences either.
| Furthermore, your example is anecdotal. There's a
| plethora of widespread non-anecdotal data to back up
| "prejudice" being accurate and helping people make wiser
| decisions.
| lngnmn2 wrote:
| Brain is conditioned by the sensory input augmented with "verbal
| knowledge" (how it is encoded is irrelevant).
|
| Religious and mystic experiences work exactly the same way. When
| many other people around you do strange things they start to make
| sense.
|
| So, basically, it is fooling of neural nets by giving strong cues
| or whatever you might call them.
|
| In religion such strong cues are other people's facial
| expressions and body language.
|
| The brain's neural networks recognize strong signals of "taking
| positive actions" or whatever.
| ramblenode wrote:
| This is the connection more people should be making. The
| placebo effect is a social effect. Somebody else whom you trust
| has given you something. More generally it is an expectation,
| but the double-blind nature of placebo studies means that it is
| also always a social transaction. The effect is boosted by the
| perceived authority of the prescriber (white coat, hospital,
| colored pill). The same mechanism probably underlies higher
| survival of religious-minded cancer patients.
| hyperpallium2 wrote:
| It's been experimentally shown that the placebo effect is
| enhanced by being administered in a hospital-like setting, by a
| person dressed as a doctor, with a big + on a big pill.
|
| My personal theory is that if you have convincing evidence that
| you are safe and being looked after, your body can divert
| resources to deal with the problem, instead of being on guard.
| agumonkey wrote:
| I agree. Similarly relativism can evaporate some pain. You can
| feel pretty bad if you think you're alone in a situation. Just
| knowing someone went through the same issue relieves part of
| the pain, even though nothing changed in your life.
| jrs235 wrote:
| Which begs the question: If placebos (sometimes) work,
| (particularly when administered in hospital settings and when
| expensive, at least in the eyes/brain of the patient) is it
| unethical to administer/provide them?
| Buttons840 wrote:
| Placebos work even when people know it's a placebo. We might
| want to establish a baseline, like the pretender has to
| remind the patient he's just a pretender once a year. But if
| a pretend doctor can help, then go for it.
| pfortuny wrote:
| It is unethical to say that you are administering a medicine
| when you are not doing it, except in trials to which the
| subject has agreed.
| Tyrannosaur wrote:
| I 100% agree, but that doesn't mean we can't still
| administer placebos:
|
| I've read elsewhere that you don't have to lie to the
| person to still have a successful placebo effect- they can
| still receive a benefit even knowing it's not a real drug.
| dairylee wrote:
| > The placebo effect can bring powerful relief
|
| Can it? I don't believe there are any studies that actually show
| this.
| Pyramus wrote:
| Yes, that's the reason RCTs are contrasted against placebo not
| no treatment.
|
| If you want too see how powerful this effect can become look no
| further than acupuncture. Or, for a nocebo result, people have
| actually died because they thought they had been cursed. Or,
| maybe less dramatic, people who are given an alcohol placebo
| still get drunk.
|
| Not all, but some do, and we don't know why they specifically
| and why at all.
| lotsofpulp wrote:
| > Or, for a nocebo result, people have actually died because
| they thought they had been cursed
|
| Source?
|
| I have yet to hear about an objective malady that can be
| fixed via placebo/nocebo, like stage 4 cancer, type 1
| diabetes, etc.
| cainxinth wrote:
| https://en.wikipedia.org/wiki/Kurdaitcha#Bone_pointing
| [deleted]
| PaulDavisThe1st wrote:
| "Objective malady" is a deliberately loaded term.
|
| Generally in medicine there's a distinction between acute
| conditions and chronic conditions.
|
| Allopathic (western) medicine has proved highly effective
| at treating acute conditions, including trauma/injury,
| certain forms of cancer and infection.
|
| However, chronic conditions are still one of the primary
| experiences of many humans relating to their health, and
| allopathic medicine has generally done quite poorly at
| addressing these conditions. Other styles of treatment,
| including placebo, have been shown to be effective in at
| least reducing the severity or incidence of the symptoms
| associated with chronic conditions.
|
| The fact that you don't want to consider someone's 20 year
| battle with chronic back pain, or neuropathy, or any other
| chronic condition, to be "an objective malady" doesn't make
| you the arbiter of what's real and what isn't.
| lotsofpulp wrote:
| > The fact that you don't want to consider someone's 20
| year battle with chronic back pain, or neuropathy, or any
| other chronic condition, to be "an objective malady"
| doesn't make you the arbiter of what's real and what
| isn't.
|
| Objective means measurable, definable, quantifiable. It
| has nothing to do with real or not. The human body is so
| complex with so many possibilities, I find it
| uninteresting to speculate about unknowns, hence
| restricting my request to what I am interested in.
|
| Dying is an objective condition observable by others, so
| it piqued my interest as to how it was determined someone
| died due to a nocebo.
| PaulDavisThe1st wrote:
| Most/many chronic conditions cannot be measured, defined,
| or quantified. The sufferer can give you some estimate on
| some scale that you describe that relates to the
| intensity and nature of their experiences.
|
| I'm very glad to have seen an increasing number of health
| care professionals say things along the lines of "we have
| no idea what is causing their experience, and in fact, we
| think most it may be entirely psychogenic, but that
| doesn't change the fact that this is what they are
| actually experiencing, and that's as real for them as a
| puncture wound or an infection."
| ChefboyOG wrote:
| I don't know of people dying from a belief that they were
| cursed, but we do certainly know that placebos can have
| very real, measurable neurobiological effects. For example,
| there many studies looking at the body's response to
| placebo painkillers. The brain often releases
| neurotransmitters that bind to opioid receptors as if an
| actual painkiller had been taken:
| https://www.nature.com/articles/535S14a
|
| The original comment was about placebos bringing "powerful
| relief," which there is a great deal of scientific research
| to support. As far as I'm aware, there is no serious
| medical researcher advancing the hypothesis that stage 4
| cancer or type 1 diabetes should or can be treated via
| placebos.
| kipchak wrote:
| I'm not up to date on if there are any counter opinions to
| this, but I've heard that placebo's are similar in effect
| to SSRIs[1] - Though as always there's a lot of buts/ifs
| there.[2] My assumption is that a placebo causes people to
| expect things to get better and reduces stress levels,
| increases sleep quality and so on. I would figure a very
| supportive social network (family, prayer group) would
| probably have a similar effect.
|
| That being said like you say for something more severe the
| placebo alone isn't going to do much, but I would imagine
| if you gave people a placebo that they thought would
| improve their stage 4 cancer recovery you would probably
| see an effect.
|
| [1]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4172306/
|
| [2]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4592645/
| allturtles wrote:
| > Yes, that's the reason RCTs are contrasted against placebo
| not no treatment.
|
| I don't think so. Placebo is used to blind participants to
| which study arm they are in. The placebo effect was then
| discovered after the fact.
| Pyramus wrote:
| You are not wrong - placebos are a practical way to blind a
| study.
|
| The best way to blind, however, is no treatment, but no
| treatment only gives you the efficacy of the treatment, and
| not what you actually want to know, the efficacy of the
| 'active ingredient'.
|
| See e.g. https://en.wikipedia.org/wiki/Placebo-
| controlled_study#Natur...
| wyager wrote:
| Placebos probably don't do much of anything compared to no
| treatment. It's almost all mean reversion.
| https://pubmed.ncbi.nlm.nih.gov/12535498/
| PaulDavisThe1st wrote:
| If you're going to reference papers from 2004, you should
| likely follow up on their subsequent citations and
| refutations:
|
| 2007 paper that specifically cites Hrobjartsson et al., but
| claims that they overlooked certain specific effects:
|
| https://bmcmedicine.biomedcentral.com/articles/10.1186/1741
| -...
|
| 2019 review that also cites Hrobjartsson et al., but
| catches up on subsequent and broader placebo/nocebo
| research and concludes that both still seem efficaceous in
| the right contexts. https://www.frontiersin.org/articles/10
| .3389/fpsyt.2019.0036...
| wyager wrote:
| That's fine, I'll easily believe "medical research can
| make no accurate predictions in this domain" - in fact,
| that's my prior. In any case, people shouldn't go around
| speaking as if placebo is this established strong
| phenomenon.
| FabHK wrote:
| Exactly. Thanks, I had forgotten where I had read that,
| this is a nice source.
|
| Here's the TL'DR: The placebo effect is maybe not quite as
| powerful as it is sometimes made out to be. And the reason
| is spontaneous remission or reversion to the mean.
|
| 1. Initially, researchers tested a treatment, and when the
| patients got healthier, it was assumed that it was the
| treatment.
|
| 2. Then researchers got smarter, and tested a treatment
| against a placebo (control), ideally double blind and
| randomised etc., and when the control group got better, it
| was assumed to be the placebo effect, and when the
| treatment group got even better, the difference was the
| treatment effect.
|
| 3. Then researchers got even smarter, and tested a
| treatment against a placebo (control) and against no
| treatment at all, and when the no-treatment group got
| better, it was assumed to be reversion to the mean or
| spontaneous remission; when the control group got even
| better, that difference was the placebo effect; and when
| the treatment group got even better, that difference was
| the treatment effect.
|
| Going from 1. to 2., it was realised that many treatments
| are not quite as potent as hoped, and that the placebo
| effect is quite strong. However, going from 2. to 3., it
| was realised that the placebo effect is not quite as potent
| either, and that there is considerable spontaneous
| remission or reversion to the mean.
| [deleted]
| wyager wrote:
| Good question. It's a shame that you're being downvoted. It's
| not clear that placebos actually do anything.
| https://pubmed.ncbi.nlm.nih.gov/12535498/
| PaulDavisThe1st wrote:
| See my other response to this link at
| https://news.ycombinator.com/item?id=29028133
| Pyramus wrote:
| Do you expect a single study to overturn decades of research
| and medical practice? Leaving aside that 'absence of evidence
| is not evidence of absence', that would need to be
| extraordinary evidence, right?
|
| I'm not surprised at all you doubt the existence - it's a
| very common phenomenon that modern medicine/science struggles
| to explain (yet) and it's a very weird phenomenon. E.g.
| placebos still work when you know it's a placebo, it works
| for animals, it works so well that insurance will cover it
| etc.
|
| Maybe Bad Science by Ben Goldacre is a good starting point as
| a book.
| wyager wrote:
| > Do you expect a single study
|
| This is a meta study.
|
| > to overturn decades of research and medical practice?
|
| "Medical practice" has an atrocious record of being based
| in fact. There is, in fact, plenty of research on placebo,
| and the preponderance seems to suggest that it's weak or
| non-existent.
|
| > E.g. placebos still work when you know it's a placebo, it
| works for animals
|
| This is consistent with, and in fact favors, the theory
| that it's actually just mean reversion.
|
| > Maybe Bad Science by Ben Goldacre is a good starting
| point as a book
|
| I don't think pop scientism books are a good place to
| start.
| Noe2097 wrote:
| This article/study is all and only about "pain modulation".
|
| Is it to say that there is only one placebo effect, which is
| always reducing pain? Aren't there placebo effects going "beyond"
| pain relieving? (Or is it the title that is generalizing the
| scope of the analysis too much?)
| richardatlarge wrote:
| We did a spoof ad for a psychiatry magazine when I was at
| Adbusters:
|
| https://static.substack.com/p/now-available
| twofornone wrote:
| So how does one deliberately trick oneself to benefit from the
| placebo effect when knowingly receiving a placebo?
|
| I guess ignorance really is bliss.
| [deleted]
| [deleted]
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