HW 6. In Homework 6, I asked you to write a short essay. I wanted you to:
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In Homework 6, I asked you to write a short essay. I wanted you to:
“Imaginethat science shows that [some treatment that is important to you] is no better than a placebo, and only works because people believe it does—it’s only the placebo effect. Imagine that the science is really good and not flawed or biased or poorly conducted.”
Some of you made arguments like this:
“Acupuncture is not just a placebo! It really does work… look at this evidence!”
And then you gave me some evidence. Sometimes even published studies.
But that’s not what I wanted. Imagine.
Imagine that those same studies– instead of saying “this works”– said “this does not work, it’s no better than a placebo.”
What would you say then? Would you still defend acupuncture?
A lot of you did answer this question (thanks!) and presented a wide range of defenses of placebos– reasons why we should still undergo certain treatments, even if all the scientific evidence said they work only through the placebo effect.
Sometimes you accepted that treatments were placebos, but argued that that was OK:
A lot of you talked about Traditional Chinese Medicine, and argued that even if science-based medical trials (experiments) had results that said TCM was only a placebo, there are other, non-science-based reasons for believing that TCM is real medicine, and really works (not only through the placebo effect).
Many of you compared TCM to “Western” medicine. I don’t like to talk that way, I think it confuses the issues.
There is lots of non-science-based Western medicine. Homeopathy, electroconvulsive therapy, chiropractic, faith healing, naturopathy, quack therapies for cancer…
Additionally, there is no reason to think that some TCM might become science-based medicine in time. For example, some studies have suggested promising effects for acupuncture for some ailments. There are also suggestions about plausible scientific mechanisms that would explain how acupuncture worked. If all that turns out– then acupuncture will be science-based.
For example there’s lots of evidence that the Chinese herb, qinghao青蒿素(artemisia) is useful in curing malaria. (Mao’s army tested 5,000 TCM remedies for malaria, and this was the only one that worked. But it worked!)
The difference between science-based medicine (SBM) and non-SBM is that
1. SBM has evidential support in the form of statistically significant RCTs
2. SBM has scientifically plausible mechanisms that explain how it works.
Common defenses of TCM that you provided were:
5. TCM has spiritual effects beyond the physical ones.
6. TCM gets taught in schools, and published in journals– even in the West! (It is recognized by authorities.)
7. It’s culturally important to use it.
There’s no cure for the common cold.
The common cold is a virus that mutates very rapidly.
Because it is a virus, antibiotic medications can’t kill it, and because it mutates so rapidly, vaccines can’t prevent it.
Some things actually do make you feel better– chicken soup, surprisingly, has some medical evidence backing it up. I eat it when I’m sick.
But I also buy zinc lozenges. I know they’re no better than placebo lozenges– but that doesn’t mean they aren’t better than nothing. Placebo lozenges do cause improvement!
A common defense of “placebo medicine” (medicine that was no better than a placebo) was that it didn’t matter whether the treatment caused the improvement or our beliefs about the treatment caused the improvement—
The improvement is all that matters!
‘Placebo’ is Latin for “I will please,” and the placebo effect is when a treatment that doesn’t by itself cause any improvement leads to positive expectations in the patient that cause improvement.
‘Nocebo’ means “I will harm,” and the nocebo effect is when an inactive treatment causes harm, because we believe that it will.
In 1986, Dr. Robert Ho Man Kwok wrote a letter to the New England Journal of Medicine, describing the symptoms he seemed to experience after eating Northern Chinese food in America: “numbness at the back of the neck, gradually radiating to both arms and the back, general weakness and palpitation.” He speculated that MSG was the cause.
In 1987, an article was published in the prestigious journal Science blaming MSG.
Since then, a large number of Americans have come to believe that they are allergic to MSG and experience CRS.
Even in Hong Kong, I see restaurants all the time that advertise “No MSG!”
But this is ridiculous!
In fact, in multiple double-blind placebo-controlled trials conducted by Geha et. al. (2000), where all the participants believed they were sensitive to/ allergic to MSG, it was found that there was no difference in reaction between the MSG group (experimental) and the placebo control group. Other similar studies have had similar results.
Where did this belief come from? Well, it probably began with normal accidental correlations, confirmation bias (only noticing the times when you felt less than perfect after eating Chinese) and “goalpost shifting”: http://www.saynotomsg.com/basics_symptoms.php lists 62 different symptoms of MSG. How likely is it that you experience one by accident every time you eat Chinese?
You also can never rule out the fact that some Americans are racially prejudiced against Chinese. They perceive the food as alien and different and thus judge it as wrong and unhealthy, not suited for “civilized” people. (I’m sure a lot of this is unconscious.)
Recently, people have started to report “Wind Turbine Syndrome.”
People living near turbines have complained of lost sleep, headaches, nasuea, memory loss, dizziness, depression… an astonishing 155 symptoms in total!
First, this isn’t real. There are no noticeable differences in health problems in communities situated near wind farms, as all 17 studies of the effects of wind farms on health have shown.
But oil and gas companies (and the politicians they’ve purchased) have an interest in convincing people that alternative energy is bad for them.
What began as someone misinterpreting the cause of (probably real) symptoms, has become a case of demagogues convincing people to be sick for their own political aims.
Something is wrong with the argument “if it works, it doesn’t matter how it works” for placebos.
The same argument could be given for nocebos: “if it hurts, it doesn’t matter how it hurts: so stop using MSG, and get rid of those wind farms!”
“The placebo effect is real medicine, because it triggers the body’s healing system. One could argue that this is the best medicine, in fact, since: a. drugs do not trigger the healing system and b. the placebo effect has no side effects.” Deepak Chopra
As to Chopra’s first claim, it’s bullshit.
Placebo’s don’t “trigger the healing system”– they don’t do anything. That’s part of the definition of ‘placebo’.
All real treatment has the same positive effect as placebos and a lot more. The real stuff.
As we’ve just seen, there are side effects even to sugar pills: nocebo effects.
But let’s suppose we’re considering a case where people believe that treatment X will help them, and X performs no better than a sugar pill in double-blind randomized placebo-controlled trials. Can X still have side effects?
Remember that a lot of evidence suggests SSRI’s (selective serotonin reuptake inhibitors, a kind of antidepressant drug) work no better at curing depression than placebos.
This does not mean they do other things no better than placebos. They are very good at making you unable to eat, sleep, or have sex.
Pure sugar pills (or saltwater injections) can’t harm you any more than your beliefs can (which can be significantly).
But invasive treatments or treatments with pharmacologically active ingredients can harm you, even if they are only as good as a placebo at helping you.
Taiwan has the highest per-capita incidence of UUC (upper urinary tract cancer) of anywhere in the world.
Plants of the genera Ephedra and Asarum produce the toxic chemical aristolochicacid which causes UUC.
TCM herbal remedies contain lots of these plants, and tests have shown they contain aristolochic acid as well.
In a case report in “Nature” in 2011, a “slimming clinic” in Belgium where women were taking Chinese herbal remedies led to more than 100 women suffering kidney failure and many of them later developing cancer…
From aristolochicacid, the same thing making Taiwan #1 in UUC!
Here’s a bottle of Saiga Antelope Horn Powder. The Saiga Antelope is critically endangered, so the fact that people take these pills is currently harming endangered species.
Sometimes “side-effects” are worth it. For example, if the disease will kill you unless you suffer through a painful debilitating treatment, it may be worth it to undergo the treatment– at least that way you’ll be alive!
Lots of cancer is treatable, and if detected early enough, almost (but never quite) 100% curable. For example, some kinds of lymphoma can be cured in otherwise healthy patients with chemotherapy and radiation therapy.
These treatments are not pleasant, and cause a lot of suffering. But the alternative is death: herbal teas don’t help.
One common defense of placebos was that sometimes, the symptoms were entirely mental: pain, unhappiness, stress, nervousness, irritability– or things that these psychological states can cause: ulcers, high heart-rate, pimples, low sex drive, etc.
If the symptoms are mental, then one might suspect that a “purely mental” cure would work. The placebo effect works by manipulating your expectations. So maybe the placebo is the best cure for certain illnesses.
To some extent, this is true: people are sick because they believe they should be (nocebo effect) and they are cured by undergoing a treatment that they believe should work (placebo effect).
But just because a condition is “psychological” does not mean that it can be cured by the placebo effect.
For example, Chronic Fatigue Syndrome (CFS) is thought by many to be an illness with purely psychological causes. People try lots of treatments for CFS, but none of them work. This is proof that not all psycholgical illnesses can be cured with a placebo.
Additionally, giving people pills or shots or magic incantations or whatever for psychological illnesses can “medicalize” those illnesses.
For example, if you give women a pill for sexual problems, then even if it works only as a placebo, they may conclude that their problems were chemical in nature, rather than psychological, a problem with relationships.
I don’t pretend to know a lot about TCM. I know very little.
I don’t want to argue here against TCM. This class is “Critical Thinking” not “Traditional Chinese Medicine.”
But it’s the hypothetical that’s important to me: imagine that science-based medicine concludes that some treatment in TCM is no better than a placebo…
Should we stop using that treatment? If TCM is better than a placebo, we don’t have to answer this question. But what if it isn’t…?
I’m not a (medical) doctor, and my job isn’t to teach you medicine, and I can’t teach you medicine.
My goal is to make you think about medicine (and other things) critically.
What are rational ways to respond to arguments– for example, arguments that certain treatments are no better than a placebo?
“Traditional Chinese Medicine works– how can it not? It’s been around for 2,000 years. The basic ideas are set forth in ‘The Yellow Emperor’s Inner Cannon’, published around 100 BCE. If it didn’t work wouldn’t someone have noticed in the past 2000 years?”
Sometimes things don’t work, and they survive.
For example, almost every Western newspaper contains a horoscope, a prediction of how your day (week) will go, based on your Zodiac sign.
(Does this happen in Chinese newspapers?)
In Western astrology, your exact date of birth determines your horoscope. On that date, certain constellations (clusters of stars) were in certain positions in the sky, and the sun, moon, and planets were in other positions relative to those constellations.
Theoretically, this predicts your entire life!
Astrology doesn’t work, however.
If you give ordinary people random horoscopes, their judgments about whether those horoscopes apply are random.
If you give astrologers descriptions of people, their judgments about which astrological sign they have are random.
Astrology is 5,000 years old.
Every Westerner knows his/her astrological sign, and most Western newspapers contain horoscopes.
All the evidence says it’s fake.
The Forer effect is the observation that people are highly inclined to believe that a description is true of them, and highly accurate if (a) they believe it is constructed from highly detailed information about them and (b) it is vague or general enough to apply to almost anyone.
“You have a great need for other people to like and admire you. You have a tendency to be critical of yourself. You have a great deal of unused capacity which you have not turned to your advantage. While you have some personality weaknesses, you are generally able to compensate for them. Your sexual adjustment has presented problems for you. Disciplined and self-controlled outside, you tend to be worrisome and insecure inside. At times you have serious doubts as to whether you have made the right decision or done the right thing…
…You prefer a certain amount of change and variety and become dissatisfied when hemmed in by restrictions and limitations. You pride yourself as an independent thinker and do not accept others' statements without satisfactory proof. You have found it unwise to be too frank in revealing yourself to others. At times you are extroverted, affable, sociable, while at other times you are introverted, wary, reserved. Some of your aspirations tend to be pretty unrealistic. Security is one of your major goals in life.”
On a scale of 0 to 5, the average accuracy rating for this prompt was 4.26, after subjects were told it was a person-specific personality analysis. In reality, the same prompt was given to all the subjects.
On horoscope.com today (Mon.) my reading was:
“Gatherings in your neighborhood could bring new and interesting information your way, Aquarius. A message from an acquaintance could send you down a new path toward a new goal. Relations with everyone around you - from your romantic partner to the most casual of acquaintances - should be warm and congenial. Conversations should be stimulating.”
They also off “Chinese horoscopes”. Mine was:
“This is a day when you're likely to have a difficult time making a choice between two options or talking a stand if someone challenges you. This "peace at any price" tendency can allow problems to simmer just below the surface. It's still necessary to display some backbone.”
I’m likely (but not certain) to have a choice if someone challenges me (and they may not) and my policy of peace at any price (do I have this?) can (but may not) allow problems to simmer just below the surface (but that doesn’t mean they will. And how would I know if they did?) It is necessary that I have some backbone (even though I might not, and it isn’t predicted what will happen if I don’t).
Sure, this doesn’t mean that all old things are still around due to the Forer Effect.
They could be here for good reasons, or on account of confirmation bias, or cultural inertia, or whatever.
But just because something is old, doesn’t make it right!
One charge against science-based medicine is that it “treats the symptoms, not the causes”, “treats the disease, not the person”, “is inflexible, and applies the same treatment to everyone”….
Alternative, non-science-based therapies are often touted as avoiding these pitfalls.
I can’t claim to know much about TCM diagnoses and treatments.
English Wikipedia says: “In TCM, a disease has two aspects: ‘bìng’ and ‘zhèng’… most of the disease entitites(病, pinyin: bìng) listed by TCM constitute mere symptoms… [证]are ultimately defined by their symptoms and ‘signs’ (i.e., for example, pulse and tongue findings).”
That might be wrong… again, I’m not the one to ask.
But similar arguments are made by Homeopaths against science-based medicine, even though Homeopathy is based entirely on symptoms. The “Law of Similars” says that like cures like, if X causes the symptoms you are experiencing, then X can cure your disease.
Finally, remember why I like calling it “science-based medicine” instead of Western medicine. It’s not about where it’s from, it’s about whether science supports it.
Lots of ‘holistic’ and preventative treatments are science-based: having a clean water supply, vaccinating your children, eating healthy, exercising, avoiding smoking and drinking…
A common defense of ineffectual treatments against science-based medicine is that they are “natural” or “herbal” and not “chemical”.
This criticism isn’t very credible…
One defense I read a number of times was that TCM had its own explanations, and didn’t need “Western” explanations, or science-based ones.
For example, TCM might diagnose a certain disease as being due to a Yin deficiency or an imbalance of xuě血.
We should distinguish between the explanations and the evidence for those explanations. You can have a nice-sounding explanation for anything you want– but is it true?
For example, you might think “HIV infection is triggered by Toxic Heat, and initially attacks the Spleen and Stomach Organ Systems.”
This of course does not suggest that you watch out for needle sharing, blood transfusions, and unprotected sex, as the germ theory suggests.
TCM is often used alongside science-based antiretroviral therapy in the treatment of AIDS. And I suppose it doesn’t harm, and it may help with symptoms, depending on the treatment.
But believing the TCM explanations for AIDS will kill you. The cause is a virus, a virus transmitted in specific ways that we know about. Believing something else puts you at risk for the disease.
Science is not just one of many ways at getting at the truth.
Science is the only way of getting at the truth.
It is just a rigorous way of applying the standards that we all believe in and use every day.
If you want to know whether eating a meat-heavy diet or a vegetarian diet is more healthy, you take two samples of people that are representative of the population, feed one group one diet and the other group the other diet, and then measure which group does better. That’s a Randomized Controlled Trial, RCT. Science-based medicine is the collection of treatments that do better in RCTs.
Arguments like “it’s ancient” or “it worked for me” or “it has this plausible-sounding explanation” are open to bias.
Confirmation bias, bias from authority, the regression fallacy, the placebo effect, the clustering illusion…
If it really works, then it works in RCTs. And if it works in RCTs, it’s science-based medicine.
Another argument that some treatments are worth continuing, even if they are no better than a placebo in RCTs, is that they may be better than a placebo in spiritual effects that are not measurable to science.
Caricature: “This treatment makes your aura brighter, even though it doesn’t make your cough go away.”
Maybe. If it’s something that can’t be observed, then I suppose there can’t be any scientific evidence against it.
But there can’t be any scientific evidence for it either. How do you know it actually makes your aura brighter or whatever?
If someone claims that they can tell, but science can’t… science can test that!
Suppose science can’t measure auras. We can still test to see whether other people can measure auras.
For example, we can randomly give either the treatment or a placebo to study participants.
Then we ask the aura reader– without telling her which group each patient belongs to– to tell us whose aura has gotten better.
If the treatment works, she should be better than chance at telling who is a control or not.
I also got this defense of TCM:
“Westerners teach TCM in medical schools. Journals of medical research publish studies of TCM. Lots of doctors use it, not just Chinese ones. How can it be no better than a placebo?”
One thing to say is that this isn’t really appropriate to the assignment. I wanted you to imagine that some treatment that was important to you was shown to be no better than a placebo. That’s consistent with all of Chinese medicine being better than a placebo. You can imagine things that are not true.
Still, let’s consider the question:
Why do medical schools, doctors, and medical journals promote fake medicine like homeopathy, reiki, naturopathy, etc.?
Why have so many Westerners turned to non-science based medicine, when the Western medical establishment is mostly science-based?
In science, nothing is ever certain. Smoking raises the probability that you’ll get cancer; undergoing radiation therapy raises the probability that you’ll beat cancer; you could get cancer if you didn’t smoke; you can die from cancer even if we do our best to treat you. Sorry, but that’s life.
People don’t like uncertainty. They don’t like feeling that things are outside their control, that their disease is caused by something they can’t see, and can’t do anything about. Uncertainty makes you feel helpless.
When you’re frustrated with throwing up from the chemo treatments, losing your hair, and feeling incredibly tired all the time…maybe its time to look at a different option.
The advantages of using Alternative Medicine:
And why do doctors latch on to non-science-based medicine?
That can be a long story, but consider the case of antidepressants again. They (or at least SSRI’s) don’t work any better than a placebo. Yet, Western doctors prescribe them all the time.
The answer is more-or-less: fraud. There are lots of ways to cheat in science. If you want your study to show that antidepressants do better than placebos, you can not double blind your studies, or use improper randomization techniques (this is obvious to real scientists, though).
You can also: