The Placebo Effect


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? If you like this video and the way we
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