A placebo is a treatment with zero therapeutic value but magical healing
power. Common placebos include sugar pills inert saline injections, other
procedures and surgeries that are completely fake. Placebos are especially
effective to treat pain, chronic stress related diseases, like insomnia, and forms
of depression. What most don't realize is that while placebos are fake the placebo
effect does it's magic even if you get real treatments from a normal doctor.
Placebos tend to follow one simple rule: the more ritualized and extreme the fake
treatment the more effective their effect. In short, sugar pills work well,
sham surgery works wonders. Since standard doctor appointments are often
highly ritualized the placebo effect is part of the cure we think we receive. To
understand this better let's look at Mr. and Mrs. Martin who both suffer chronic
back pain. Mr. Martin feels the pain first and he decides to go see a doctor
who diagnoses osteoporosis and treats him with physiotherapy. After a few days
of treatment, Mr. Martin feels better. He starts to track the progress of his pain.
He soon learns that he always goes to the doctor on the days when the pain is
the worst and always feels better soon after. He becomes a big advocate for
physiotherapy and recommends it to his wife and she joins him. But do we really
know that the therapy works? Despite months of therapy things get worse for
both Mr. and Mrs. Martin. Together they go to the hospital where Mr. Martin's
doctor prescribes painkillers. Mrs. Martin decides to get a second opinion.
Her new doctor has recently learned that for some chronic pain placebos work
equally well. Instead of giving Mrs. Martin painkillers
the doctor prescribes simple sugar pills though he tells Mrs. Martin that they
are pain killers. The next day they both feel much better.
Mr. Martin notices that he has no problem sawing wood and Mrs. Martin can
easily put on her shoes. She can confirm that the painkillers work but do they
really? Unfortunately, it doesn't take long before the pain comes back and they
return to the hospital. Mr. Martin is now treated with
vertebroplasty, a popular treatment offered to people who suffer from back
pain due to osteoporosis. To administer it the doctors inject cement directly
into his vertebrae, the bones that form the spinal column. Mrs. Martin's doctor
simply has her smell a container full of cement and then administers a saline
injection, which does nothing. Her doctor learned about this placebo
from research published in the U.S. National Library of Medicine. It showed
that a large randomized controlled trial found no benefit of vertebroplasty over
a sham procedure. Right after the surgery the Martin's meet in the lobby and share
their experience of the process: both feel great! Mrs. Martin invites her
husband for ice cream as her treatment was so much cheaper. So what's happening
here? There are a couple of theories that try to explain the placebo effect. First
there is regression to the mean: Mr. Martin like most of us thinks about
treatment when his symptoms are particularly bad. He goes to see a doctor
and soon after feels better. If we look at the natural course of many illnesses
we understand that pain, over time, comes and goes in swings and usually regresses
to the mean. We don't know if the doctor or placebo had anything to do with the
improvement. Then there is classical conditioning:
most treatments, including vertebroplasty, are delivered in a context of rituals
that include social signals, physical cues, and verbal suggestions. Mr. Martin's
brain interprets such cues and elicits expectations memories and emotions, it
releases endorphins and other chemicals that make him feel good and lower his
perception of pain. So it becomes a self-fulfilling prophecy where a belief
that he feels better leads him to feel better. And there is confirmation bias: as
soon as Mrs. Martin takes the sugar pill she thinks she will feel better. Then she
focuses only on the things that confirm that she is better. She doesn't realize
that she still has trouble doing many other things. While all three ideas
probably work together there is another theory: so-called mirror neurons might
also play a role. A new and growing body of evidence points at brain cells that
mirror behavior. The cells fire when one acts and when one observes the same
action performed by another. As Mrs. Martin talks to the doctor parts of the
doctors brain will mirror parts of her brain and parts of her brain will mirror
his, as a result, the structure of her brain changes and she feels less pain.
The neurophysiologist Giacomo Rizzolatti who discovered mirror neurons suggests
that this process bypasses consciousness and provides a direct mapping of sensory
information onto motor structures.
Placebo, a Latin word that means "I will please", have been used for thousands of
years. Placebo effects have been discussed for centuries. An influential
study from 1955 by Henry Kay Beecher, Harvard, titled: the powerful placebo
established the idea that the effect is clinically important. Today the placebo
effect is well recognized and scientifically so significant that any
new pain medication that seeks Food and Drug Administration approval in the
United States needs to show that it works better than a placebo treatment. In
so-called randomized controlled trials, the gold standard of medical research,
one group of patients is given the new medication while a control group receives
a placebo. Neither the doctors who hand out the
medication nor the patients know who gets what. Once the trial is over results
are compared. If the new medication works significantly better than the placebo it's
allowed to be sold. The trial is surprisingly difficult from 10 new drugs
entering the test one gets approval. If a placebo study proves that an existing
standard medical procedure is ineffective, like in the case of
vertebroplasty, competent doctors stop prescribing it and we can speak of
medical reversal. To find out if an existing treatment works or if it's
healing power is just the result of the placebo effect we can administer
treatment without the knowledge of the patients. In one such experiment it was
shown that if a painkiller is administered by a hidden robot pump,
patients demanded twice the dose compared to when the drug is injected by
a nurse. This would suggest that if a patient is completely unaware that
treatment is being given, the treatment is just half as effective. The placebo
effect counts for the other half. Honest placebo studies go even further.
Because deception is ethically questionable researchers have now
started to do clinical trials in which people are told that all they get is a
sugar pill with placebo printed all over the packaging. And even then the placebo
effect does it's magic and helps you feel better.
One experiment at the Harvard Medical School showed that people suffering from
irritable bowel syndrome who were taking the honest placebo doubled their rate of
improvement compared to the control group. What do you think? How can we make
sure that the medicine we are prescribing is not only effective thanks
to the placebo effect? Will more placebo research reveal that many standard
medical treatments offered in some of the best hospitals around the world are
shams? And how can we research the power of placeboes ourselves, at home, without
putting anyone in danger?
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