4 ms·

It’s way more complicated than that. The diagnostic criteria changes over time, for many diseases with psychological components, in ways that make formerly path

It’s way more complicated than that. The diagnostic criteria changes over time, for many diseases with psychological components, in ways that make formerly pathological behaviors now healthy and vice versa. Placebo doesn’t actually help you, obviously, despite what the outcome you’re measuring suggests. It represents a slack (something not quite an error, but not quite a useful measurement) in the outcomes based measurement regime. It’s a “cosmological constant” as a side effect of the limitations of enumerating causal and contributing factors. People believe acupuncture is a placebo, and in an evidence based medicine regime it seems reasonable to prescribe it. But it depends what you’re calling pathological. Today, a population of video game players versus a control will score better on many psych outcomes. Tomorrow, they’ll change the tests, subtly, to account for “factors” better, and the results will reverse. The USMLE study book in 2018 pathologizes “video game fixation” (they can’t call it an addiction) before such a test change has occurred. The simple rule is that whatever society determines to be pathological will trickle down to the field of medicine, and placebo effects are the loudest signal of the limitations of an otherwise most superior way to administer therapies.

logifail 8y ago
> Placebo doesn’t actually help you What? The first definition of the placebo effect I found was this: "a beneficial effect produced by a placebo drug or treatment, which cannot be attributed to the properties of the placebo itself, and must therefore be due to the patient's belief in that treatment" My highlight.
- UnFleshedOne 8y ago
  He means that most of the placebo is covered by a statistical effect, regression to the mean, etc. https://sciencebasedmedicine.org/the-placebo-myth/ https://sciencebasedmedicine.org/the-placebo-myth/
  - btilly 8y ago
    That may be most of the effect on the group taking the placebo. But it is not the placebo effect. Were there no placebo effect, then we could test the effectiveness of drugs by simply observing one group and giving the other our proposed treatment.
    - logifail 8y ago
      There are drug candidates that make it all the way to phase 3 trials before they fail. One of the (surprisingly?) common reasons for failure at this stage is turning out to be less effective than placebo https://www.nuventra.com/resources/blog/placebo-response-phase-3-failures/ https://www.nuventra.com/resources/blog/placebo-response-pha... https://seekingalpha.com/article/256697-why-phase-3-trials-fail-what-investors-need-to-know https://seekingalpha.com/article/256697-why-phase-3-trials-f...
      - btilly 8y ago
        Reading the articles left me with the impression not that they were less effective, but that they couldn't prove efficacy. So they could win, or lose, but it was close. It is also worth noting that one of the reasons why this happens in stage 3 despite having passed through a test in stage 2 that was meant to whittle this out is that improved expectations increase the strength of the placebo effect. Which makes the real effect harder to detect.
        logifail 8y ago
        > not that they were less effective, but that they couldn't prove efficacy Could you explain the difference?
        btilly 8y ago
        To prove efficacy, you have to have a statistically significant win. If you're ahead by a small margin, it isn't evidence that you're less effective. But you did not prove efficacy.
  - logifail 8y ago
    > "Aint no such thing as a placebo effect, only a change in perception" I find that statement disingenuous. Is the author really claiming that "a change in perception" isn't real?
- deleted 8y ago
  [deleted]
btilly 8y ago
You're right that changes in diagnostic criteria and statistical effects can cause a placebo group to look better or worse over time without the placebo having done anything. This is important, and thank you for the reminder. However that is not to say that the placebo effect never helps you. As http://protomag.com/articles/the-placebo-problem http://protomag.com/articles/the-placebo-problem shows, people who are receiving a placebo will experience medically significant effects, and which effects they experience depend on which placebo they got. Furthermore the reason why double blind studies became standard is that it turns out that the doctor's knowledge has an impact even when the doctor is trying to not communicate it. That is, if doctors are told that one group is receiving a placebo and another is not, the group that is not will do better EVEN THOUGH both groups are in fact receiving the same placebo! (I heard about this some time ago as a classic study, but I can't seem to track it down easily.)
- doctorpangloss 8y ago
  Yes, I agree. I think my point really is that clinical outcomes care about how the patient feels, while scientific outcomes (like whether your medicine works the way you think it does) usually does not. We got a lot of great medicine whose biomechanics we don’t really understand and whose trials don’t prove but definitely safely and significantly help people. A study just seeking to prove that your drug does the biomechanics it claims measures a placebo effect of zero if it is done correctly, because if you observe a placebo effect you’re not dealing with a biomechanically constrained outcome anymore. There isn’t really a viable alternative to evidence based medicine, it’s the only game in town. We just have to carefully decide what outcomes we care about and whether or not those outcomes (1) discourage scientific understanding of the underlying biomechanics of our drugs, by virtue of making black-boxedness acceptable and (2) are co-opted, via enemy action, by either conspiracy theorists sowing doubt in things like vaccines or moneyed interests who make mediocre drugs look good.

logifail 8y ago

> Placebo doesn’t actually help you What? The first definition of the placebo effect I found was this: "a beneficial effect produced by a placebo drug or treatment, which cannot be attributed to the properties of the placebo itself, and must therefore be due to the patient's belief in that treatment" My highlight.

UnFleshedOne 8y ago
He means that most of the placebo is covered by a statistical effect, regression to the mean, etc. https://sciencebasedmedicine.org/the-placebo-myth/ https://sciencebasedmedicine.org/the-placebo-myth/
- btilly 8y ago
  That may be most of the effect on the group taking the placebo. But it is not the placebo effect. Were there no placebo effect, then we could test the effectiveness of drugs by simply observing one group and giving the other our proposed treatment.
  - logifail 8y ago
    There are drug candidates that make it all the way to phase 3 trials before they fail. One of the (surprisingly?) common reasons for failure at this stage is turning out to be less effective than placebo https://www.nuventra.com/resources/blog/placebo-response-phase-3-failures/ https://www.nuventra.com/resources/blog/placebo-response-pha... https://seekingalpha.com/article/256697-why-phase-3-trials-fail-what-investors-need-to-know https://seekingalpha.com/article/256697-why-phase-3-trials-f...
    - btilly 8y ago
      Reading the articles left me with the impression not that they were less effective, but that they couldn't prove efficacy. So they could win, or lose, but it was close. It is also worth noting that one of the reasons why this happens in stage 3 despite having passed through a test in stage 2 that was meant to whittle this out is that improved expectations increase the strength of the placebo effect. Which makes the real effect harder to detect.
      - logifail 8y ago
        > not that they were less effective, but that they couldn't prove efficacy Could you explain the difference?
        btilly 8y ago
        To prove efficacy, you have to have a statistically significant win. If you're ahead by a small margin, it isn't evidence that you're less effective. But you did not prove efficacy.
- logifail 8y ago
  > "Aint no such thing as a placebo effect, only a change in perception" I find that statement disingenuous. Is the author really claiming that "a change in perception" isn't real?
deleted 8y ago
[deleted]

btilly 8y ago

You're right that changes in diagnostic criteria and statistical effects can cause a placebo group to look better or worse over time without the placebo having done anything. This is important, and thank you for the reminder. However that is not to say that the placebo effect never helps you. As http://protomag.com/articles/the-placebo-problem http://protomag.com/articles/the-placebo-problem shows, people who are receiving a placebo will experience medically significant effects, and which effects they experience depend on which placebo they got. Furthermore the reason why double blind studies became standard is that it turns out that the doctor's knowledge has an impact even when the doctor is trying to not communicate it. That is, if doctors are told that one group is receiving a placebo and another is not, the group that is not will do better EVEN THOUGH both groups are in fact receiving the same placebo! (I heard about this some time ago as a classic study, but I can't seem to track it down easily.)

doctorpangloss 8y ago
Yes, I agree. I think my point really is that clinical outcomes care about how the patient feels, while scientific outcomes (like whether your medicine works the way you think it does) usually does not. We got a lot of great medicine whose biomechanics we don’t really understand and whose trials don’t prove but definitely safely and significantly help people. A study just seeking to prove that your drug does the biomechanics it claims measures a placebo effect of zero if it is done correctly, because if you observe a placebo effect you’re not dealing with a biomechanically constrained outcome anymore. There isn’t really a viable alternative to evidence based medicine, it’s the only game in town. We just have to carefully decide what outcomes we care about and whether or not those outcomes (1) discourage scientific understanding of the underlying biomechanics of our drugs, by virtue of making black-boxedness acceptable and (2) are co-opted, via enemy action, by either conspiracy theorists sowing doubt in things like vaccines or moneyed interests who make mediocre drugs look good.