"The Placebo Effect" (from 2008) (Science-Based Medicine)

[Dolphin]

Explains how apparent placebo effects are generally artifacts

https://www.sciencebasedmedicine.org/the-placebo-effect/

 

[Dolphin]

The various factors that contribute to a measured or perceived placebo effect vary depending upon the situation – what symptoms or outcomes are being observed. Subjective outcomes like pain, fatigue, and an overall sense of wellbeing, are subject to a host of psychological factors. For example, subjects in clinical studies want to get better, they want to believe they are on the active experimental treatment and that it works, they want to feel that the time and effort they have invested is worthwhile, and they want to make the researchers happy. In turn, the researchers want their treatment to work and want to see their patients get better. So there is often a large reporting bias. In other words, subjects are likely to convince themselves they feel better, and to report that they feel better, even if they don’t. Also, those conducting a trial will tend to make biased observations in favor of a positive effect.

 

[Dolphin]

It has also been clearly demonstrated that subjects who are being studied in a clinical trial objectively do better. This is because they are in a clinical trial – they are paying closer attention to their overall health, they are likely taking better care of themselves due to the constant reminder of their health and habits provided by the study visits and attention they are getting, they are being examined on a regular basis by a physician, and their overall compliance with treatment is likely to be higher. So basically, subjects in a trial take better care of themselves and get more medical attention than people not in trials. If for those not in a clinical trial, if they decide to do something about their health by starting a new treatment, they are likely to engage in more healthful behavior in other ways.

 

[Dolphin]

There is no compelling evidence that the mind can create healing simply through will or belief.

 

[Dolphin]

But the more concrete and physiological the outcome, the smaller the placebo effect. Survival from serious forms of cancer, for example, has no demonstrable placebo effect. There is a “clinical trial effect,” as described above – being a subject in a trial tends to improve care and compliance, but no placebo effect beyond that. There is no compelling evidence that mood or thought alone can help fight off cancer or any similar disease.

 

[Sean]

There is no compelling evidence that the mind can create healing simply through will or belief.

There is no compelling evidence that mood or thought alone can help fight off cancer or any similar disease.

And if there is no compelling evidence of curative properties, then that brings into question the flip side of that alleged causal pathway – the nocebo – the proposition that mood and thought can create disease.

 

[IreneF]

And if there is no compelling evidence of curative properties, then that brings into question the flip side of that alleged causal pathway – the nocebo – the proposition that mood and thought can create disease.

Following the observation that people in a clinical trial take better care of themselves--people who are thinking "bad thoughts" are less likely to take care of themselves. Because why bother? etc etc

 

[Battery Muncher]

Following the observation that people in a clinical trial take better care of themselves--people who are thinking "bad thoughts" are less likely to take care of themselves. Because why bother? etc etc

Also (as I'm sure you agree), as someone who developed ME/CFS gradually over two years, I think biological changes often precede changes in mood.

I.e. the disease starts first, then this subsequently has an impact on mood.

 

[Dolphin]

One of the comments says:

psamathos • 9 years ago
Thanks for the interesting write-up. I also found Mark Crislip's podcast about the placebo effect informative, if anyone else is looking for more information on misconceptions about the placebo effect: http://www.quackcast.com/Quack...

The link is broken but I found it:

QuackCast 5. http://www.pusware.com/quackcast/quackcast5.mp3 Placebo Effect. Alt.med effects are often attributed to the placebo effect. Turns out the placebo effect does not exist. So when the effect of alt.med is equal to placebo effect, it is the same as saying it is equal to nothing. How true, how true. 5/22/06

It is 12 minutes long.

 

[Dolphin]

The podcast refers to this study:

http://www.nejm.org/doi/full/10.1056/NEJM200105243442106

N Engl J Med. 2001 May 24;344(21):1594-602.
Is the placebo powerless? An analysis of clinical trials comparing placebo with no treatment.
Hróbjartsson A1, Gøtzsche PC.
Author information

Abstract
BACKGROUND:
Placebo treatments have been reported to help patients with many diseases, but the quality of the evidence supporting this finding has not been rigorously evaluated.

METHODS:
We conducted a systematic review of clinical trials in which patients were randomly assigned to either placebo or no treatment. A placebo could be pharmacologic (e.g., a tablet), physical (e.g., a manipulation), or psychological (e.g., a conversation).

RESULTS:
We identified 130 trials that met our inclusion criteria. After the exclusion of 16 trials without relevant data on outcomes, there were 32 with binary outcomes (involving 3795 patients, with a median of 51 patients per trial) and 82 with continuous outcomes (involving 4730 patients, with a median of 27 patients per trial). As compared with no treatment, placebo had no significant effect on binary outcomes (pooled relative risk of an unwanted outcome with placebo, 0.95; 95 percent confidence interval, 0.88 to 1.02), regardless of whether these outcomes were subjective or objective. For the trials with continuous outcomes, placebo had a beneficial effect (pooled standardized mean difference in the value for an unwanted outcome between the placebo and untreated groups, -0.28; 95 percent confidence interval, -0.38 to -0.19), but the effect decreased with increasing sample size, indicating a possible bias related to the effects of small trials. The pooled standardized mean difference was significant for the trials with subjective outcomes (-0.36; 95 percent confidence interval, -0.47 to -0.25) but not for those with objective outcomes. In 27 trials involving the treatment of pain, placebo had a beneficial effect (-0.27; 95 percent confidence interval, -0.40 to -0.15). This corresponded to a reduction in the intensity of pain of 6.5 mm on a 100-mm visual-analogue scale.

CONCLUSIONS:
We found little evidence in general that placebos had powerful clinical effects. Although placebos had no significant effects on objective or binary outcomes, they had possible small benefits in studies with continuous subjective outcomes and for the treatment of pain. Outside the setting of clinical trials, there is no justification for the use of placebos.

 

[Esther12]

The podcast refers to this study:

There's also a 2010 update that is a bit more positive for placebo, but not much: http://www.ncbi.nlm.nih.gov/pubmed/20091554

AUTHORS' CONCLUSIONS:
We did not find that placebo interventions have important clinical effects in general. However, in certain settings placebo interventions can influence patient-reported outcomes, especially pain and nausea, though it is difficult to distinguish patient-reported effects of placebo from biased reporting. The effect on pain varied, even among trials with low risk of bias, from negligible to clinically important. Variations in the effect of placebo were partly explained by variations in how trials were conducted and how patients were informed.