Placebo effect includes price, study reveals
By Dennis O'Brien | Sun re****ter
March 8, 2008
http://www.baltimoresun.com/news/health/bal-te.placebo08mar08,0,6816992.story
For years, experts have known that placebos - fake injections and
pills with no real medication - can improve the health of patients
with pain, asthma, high blood pressure and angina.
Now they've learned that raising the price of a fake pill makes it
work even better.
A re****t this week in The Journal of the American Medical Association
shows that expectations - shaped by factors that include the price of
a medication - play a key role in how we respond to pain relievers and
our response to therapies for depression, cancer, stroke or heart
attack.
The new re****t adds to a store of knowledge about placebos, a subject
that has long fascinated scientists. Understanding placebos could
unravel mysteries about the body's ability to heal itself, they say.
Experts do know one reason placebos work: They raise our expectations.
Make someone believe that a tablet will make a headache disappear and
it often does - even if it turns out to be a sugar pill.
"Expectations create a different reality for us, which we don't really
appreciate," said Dan Ariely, a behavioral economist at Duke
University.
Researchers typically use placebos as controls in clinical trials of
medicines and other therapies. Some volunteers get the real drug,
while others get identical-looking placebos. It's not unusual for
placebos to work almost as well as, and in some cases better than, the
drugs being tested.
In the latest study, Ariely applied electric shocks to the wrists of
80 volunteers before and after giving each one a placebo painkiller.
He told half that the pills cost $2.50 each, and told the other half
that they cost 10 cents apiece.
Bottom line: about 60 percent of the 10-cent group re****ted pain
reduction from the placebo, compared with 85 percent of the "higher-
priced" group. None of the test subjects, who received $30 for their
trouble, actually received a painkiller.
"It says something about our expectations and how they shape reality,"
Ariely said. "Price is just one of the things we use to make
inferences."
Experts say the results also show the im****tance of boosting the hopes
of patients treated for a wide variety of ailments.
"Our response to any intervention is partly the result of the power of
the intervention, and partly the result of our expectations going in,"
said Alan Bellack, a professor of psychiatry at the University of
Maryland School of Medicine.
Placebos have improved outcomes in studies of chronic pain, anxiety,
high blood pressure, angina, asthma, ulcers, Parkinson's disease and
rheumatoid arthritis, said Irving Kirsch, a psychologist who studies
placebos at the University of Hull in England.
Kirsch reviewed 35 clinical trials of antidepressants, submitted by
drug companies to the FDA, and found that placebos did just as well as
the real drug with moderately depressed patients.
The review, published last month in The Public Library of Science,
also found only a small, "clinically insignificant difference" between
placebos and the real drugs among patients who were severely
depressed. Even so, Kirsch said that patients on antidepressants
should talk to their doctors before stopping them.
So, how do placebos work their magic? Researchers have known for years
that they trigger a biochemical response in the brain, releasing
neurotransmitters such as dopamine that act as natural painkillers.
They also know that packaging can enhance the effect.
If researchers wear white lab coats, talk in a soothing voice or
somehow instill confidence in volunteers, the placebo is usually more
effective, said Dr. Donald Price, a neuroscientist at the University
of Florida who has studied the subject for 30 years.
Coloring a tablet red makes it work better than a white pill, he said.
Showing volunteers the placebo as they receive it enhances its effect
compared with telling a volunteer he will get it through an
intravenous feed at some indeterminate future time, he said.
"Little things can make a big difference in terms of any benefit that
accrues to the patient," Price said.
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