The Placebo Effect

[Ziggurat]

Next article is up:

The idea that four placebo pills are more powerful than two sounds magical – because it isn’t true

Make sure you go to the article, because there are links.

It wasn't actually that long ago that somebody proved stomach ulcers were caused by bacteria. But it was still long enough ago that everyone should know that. If I were on the IRB for any placebo studies of stomach ulcer treatments, I wouldn't allow them to proceed. Even if placebo treatment was better than no treatment, letting patients suffer from completely treatable conditions in order to study sub-optimal treatments seems highly unethical to me.

 

[Pixel42]

My understanding is that, once an effective treatment for a condition is known, new treatments which are hoped will be even more effective are compared to that rather than placebo. So the control group gets the existing treatment, whose effectiveness compared to placebo has already been established.

 

[Ziggurat]

My understanding is that, once an effective treatment for a condition is known, new treatments which are hoped will be even more effective are compared to that rather than placebo. So the control group gets the existing treatment, whose effectiveness compared to placebo has already been established.

Looking at the article, it seems like a lot of the placebo studies were actually quite old, dating back to the 70s, and a lot of the newer papers were just meta studies using that old data.

Given what we now know about replication crisis, using data that old which cannot even ethically be retested seems rather dubious. I wouldn’t trust any of it.

 

[arthwollipot]

Looking at the article, it seems like a lot of the placebo studies were actually quite old, dating back to the 70s, and a lot of the newer papers were just meta studies using that old data.

Given what we now know about replication crisis, using data that old which cannot even ethically be retested seems rather dubious. I wouldn’t trust any of it.

Yes, most of the data supporting a "powerful placebo" effect is old, but that just means that it has had longer to seep into the public consciousness. That's common with the public understanding of science - it usually lags well behind the cutting edge. Most people who are anti-nuclear energy are unaware of 4th generation fast breeder reactors, for example.

The powerful placebo effect demonstrates the same trend as other studies of pseudoscience, like homeopathy and psychic ability. The tighter the controls, the smaller the effect.

 

[jonesdave116]

Just reading this thread made me feel better! It's a miracle!

 

[arthwollipot]

I swear, I didn't contact him. He found us all on his own.

 

[Chanakya]

Okay, there was this view presented in this thread, that the placebo isn't really the "I think I'm getting better, therefore I do get better" that I'd believed to be, but merely a catch-all for all effects not attributed to individual causes and/or controlled for. And, given that people here tend in general to know that they're talking about, I accepted that as true.

In connection with something entirely unrelated to this thread (or indeed this forum), I'd just now been googling around a bit about the placebo effect, and it seems the overwhelming majority of references that come up do state that, to quote one random but representative sample, "the placebo effect is triggered by the person's belief in the benefit from the treatment and their expectation of feeling better".

So, what the hell is the placebo effect? Is there a psychological/psychosomatic element in play here or not?

Do people here who're saying there's no psychological mumbo jumbo involved, have any evidence to back up that claim? (Now I realize that's reversing the burden of proof thing, but, I mean to say, just plug "placebo", or "placebo effect" into your search engine, and see what comes up. Practically every hit will tell you about this psychosomatic angle. So is everyone out there wrong, and just we here right? A pinch of salt, that is to say, a pinch of evidence, might be called for here, no matter which way the burden of proof actually points.)

 

[Thermal]

Possibilities:

-patient's perception of symptoms altered by belief in treatment.
-patent was improving anyway and would have felt better with no placebo pill
-patient's belief in treatment kicked in body's natural endorphins or whatever
-placebo was in fact morphine and patient got hella high

 

[Chanakya]

Possibilities:

-patient's perception of symptoms altered by belief in treatment.
-patent was improving anyway and would have felt better with no placebo pill
-patient's belief in treatment kicked in body's natural endorphins or whatever-placebo was in fact morphine and patient got hella high

Does stuff like the highlighted actually happen?

I'd originally assumed it does. (Casually enough, and without giving it any thought.) It was brought up in this thread that it doesn't, and that placebo is merely a catchall term for all uncontrolled variables. And I saw no reason to doubt what was said here, and updated my views on this.

But now I find, on looking this up cursorily (in context of a discussion IRL) that most references that pop up do bring up the psychosomatic angle, the psychology thing ... the sort of thing you'd brought up here, and that I've highlighted above.

So that, I was wondering, what the case actually is.

 

[Thermal]

Does stuff like the highlighted actually happen?

I'd originally assumed it does. (Casually enough, and without giving it any thought.) It was brought up in this thread that it doesn't, and that placebo is merely a catchall term for all uncontrolled variables. And I saw no reason to doubt what was said here, and updated my views on this.

But now I find, on looking this up cursorily (in context of a discussion IRL) that most references that pop up do bring up the psychosomatic angle, the psychology thing ... the sort of thing you'd brought up here, and that I've highlighted above.

So that, I was wondering, what the case actually is.

Anecdotally, I'm quite positive you can will yourself to feeling better on the short term, sometimes for very physical damage that I can only attribute to a very real painkiller flowing in my veins. The hitch is very short term, IME.

 

[steenkh]

So, what the hell is the placebo effect? Is there a psychological/psychosomatic element in play here or not?

Placebo is the inert treatment used in a study to contrast with an active treatment. The placebo effect is whatever effect appears in contrast to not getting a treatment at all. Any mechanism is possible.

Bias, psychosomatics, statistics, treatments ignored in the study. All is possible.

 

[Chanakya]

Placebo is the inert treatment used in a study to contrast with an active treatment. The placebo effect is whatever effect appears in contrast to not getting a treatment at all. Any mechanism is possible.

Bias, psychosomatics, statistics, treatments ignored in the study. All is possible.

That highlighted is the key part I was asking about. Is it a thing at all? Because if it is, then it brings up right back to where we started from (as far as this aspect of the discussion).

To be fully clear: If there's a psychosomatic element at play, with placebos, then absolutely, there's an argument to be made for actively and deliberately capturing that effect, using whatever means, including for instance homeopathy. That that doesn't actually happen, was a large part of what this thread was about.

It would be nice to be able to arrive at some kind of conclusion that is, well, conclusive, and evidenced, as far as whether or not psychosomatic effects form any (significant) part of the placebo effect.

 

[Ziggurat]

That highlighted is the key part I was asking about. Is it a thing at all?

Probably. The weak placebo effect (meaning you feel better, not that you actually are better) does appear to be real. The strong placebo effect (meaning it can actually help you get better) does not appear to be real.

To be fully clear: If there's a psychosomatic element at play, with placebos, then absolutely, there's an argument to be made for actively and deliberately capturing that effect, using whatever means, including for instance homeopathy. That that doesn't actually happen, was a large part of what this thread was about.

A weak placebo may be worth exploiting by some means, but definitely not by any means. In particular, promoting homeopathy may have negative consequences that outweigh any benefits.

 

[arthwollipot]

A weak placebo may be worth exploiting by some means, but definitely not by any means. In particular, promoting homeopathy may have negative consequences that outweigh any benefits.

The main risk of relying on the weak placebo effect of, eg., homeopathy is that people will rely on that and neglect getting real medical aid.

 

[Chanakya]

Probably. The weak placebo effect (meaning you feel better, not that you actually are better) does appear to be real. The strong placebo effect (meaning it can actually help you get better) does not appear to be real.

Thanks for the clarification.

A weak placebo may be worth exploiting by some means, but definitely not by any means. In particular, promoting homeopathy may have negative consequences that outweigh any benefits.

The main risk of relying on the weak placebo effect of, eg., homeopathy is that people will rely on that and neglect getting real medical aid.

Sure, agreed.

But still, in as much this weak placebo's a thing, it's easy to imagine lots of ways to deliberately channel it. There's a great deal of medication that's designed to have people feel better, or feel less bad. That would represent a huge potential for deliberately using placebos, surely, whether (in some case) in place of medication, or whether along with medication. My impression --- admittedly uninformed impression, and I could be mistaken --- that this isn't really done, or at least done much.

 

[Ziggurat]

But still, in as much this weak placebo's a thing, it's easy to imagine lots of ways to deliberately channel it. There's a great deal of medication that's designed to have people feel better, or feel less bad. That would represent a huge potential for deliberately using placebos, surely, whether (in some case) in place of medication, or whether along with medication. My impression --- admittedly uninformed impression, and I could be mistaken --- that this isn't really done, or at least done much.

I suspect it's done quite a lot, just not talked about much because nobody wants to hear they got a placebo instead of real treatment. A patient comes to see a doctor with some minor problem, the doctor prescribes something, the patient leaves satisfied regardless of whether the medication actually does anything for their problem. And that's frequently OK, since many ailments resolve on their own anyways.

 

[Prometheus]

This thread brings back a vague memory I have of a discussion when I first joined the JREF forum. I'll have to see if I can find it...

 

[arthwollipot]

New paper in the Medical Journal of Australia (MJA):

Placebos in clinical care: a suggestion beyond the evidence

Christopher G Maher, Adrian C Traeger, Christina Abdel Shaheed and Mary O'Keeffe
Med J Aust 2021; 215 (6): 252-253.e1. || doi: 10.5694/mja2.51230
Published online: 20 September 2021

The recent enthusiasm for the clinical use of placebos seems driven by myths and misunderstandings

In the past few years, major medical journals have published commentaries considering whether placebos may have a role in clinical care. Some commentators seem to have concluded that placebos should be part of clinical care and have provided advice on implementation: “Clinician education, training manuals, and workshops might help with initial implementation”.1

The clinical use of placebos is often justified by pointing to their important treatment effects. Proponents have also argued that the placebo effect can be amplified by manipulating the physical appearance of the pill,2 that placebo effects vary across geographic regions,3 and that placebos are getting more effective over time.4,5 It has even been suggested that subterfuge is unnecessary; placebos can be honestly described as inert and still yield important clinical effects.1,6 Given the recent advocacy for the clinical use of placebos, it is timely to consider the evidence underpinning these claims.

...

Conclusion

Placebos remain important for clinical trials because they help achieve blinding and, thus, control of bias; however, there is no evidence that placebos have much to offer for clinical care. When administered in a blinded fashion, a placebo will provide a small effect, but the real treatment will normally provide better outcomes for the patient. A placebo supporter could counter that they could get a bigger placebo treatment effect by dispensing large, red, unusually shaped placebo pills, but they would be basing this on uncertain evidence. It may be better to dismiss placebos and instead manage patients with evidence‐based treatments.

 

[arthwollipot]

Here's the asthma article:

Placebo inhalers can’t treat asthma: another ‘powerful placebo’ myth busted

...The study found that patients using the real salbutamol inhaler reported a 50% improvement from baseline, and patients receiving no treatment arm reported just a 21% improvement. Astonishingly, patients using the fake inhaler reported a massive 45% improvement from baseline, almost as large as salbutamol.

A startling result, I’m sure you’d agree. A fake inhaler, with no medicine in it, improved asthma symptoms almost as much as salbutamol. In fact, there was no statistically significant difference between salbutamol, the fake inhaler, and the sham acupuncture. A powerful placebo indeed, and let’s be honest, this is bad news for salbutamol, which according to these data is no better than placebo.

But that’s just the data gathered when the patients were asked how they thought they were doing. The study did not rely solely on that measure but also recorded an objective measure of lung function: Forced Expiratory Volume (FEV) or, how hard you can blow into a tube.

The FEV data tell quite a different story from the patient self-reports. Again, patients using salbutamol had an objectively measurable 20% improvement in lung function, as measured by FEV. Patients getting no treatment had much smaller 7.1% improvement. However, using this objective measure, the placebo inhaler showed only a 7.5% improvement and the sham acupuncture only a 7.3% improvement, neither of which is statistically different to no treatment...

...They aren’t lying, certainly not maliciously. They genuinely believe that they are or will be doing better, even though we know from their lung function tests that they haven’t improved any more than if we had done nothing. There is no magic here, no demonstration of the amazing power of the mind over the body. Just psychology and statistics.

To the extent that we observe real objective clinical effects, they don’t look to be related to the placebo. To the extent we receive subjective clinical reports of placebo effects, they look very much like biased reporting.

 

[steenkh]

Here's the asthma article:

Placebo inhalers can’t treat asthma: another ‘powerful placebo’ myth busted

This is again a confirmation that you can’t treat illnesses with placebo, but you can treat patients’ perception of the illnesses.