[Can a 1/4 point rate cut restore restore a financial system to
health via placebo effect? Would a 1/4 point rate cut in Germany have 10 times the curative effect as one in Brazil?]
"Placebos Prove So Powerful Even Experts Are Surprised"
By SANDRA BLAKESLEE -- October 13, 1998
Many doctors know the story of "Mr. Wright," who
was found to have cancer and in 1957 was given
only days
to live. Hospitalized in Long Beach, Calif., with
tumors the size of oranges, he heard that scientists
had discovered a horse serum, Krebiozen, that appeared
to be effective against cancer. He begged to receive
it.
His physician, Dr. Philip West,
finally agreed and gave Wright an
injection on a Friday afternoon. The
following Monday, the astonished
doctor found his patient out of his
"death bed," joking with the nurses.
The tumors, the doctor wrote later,
"had melted like snow balls on a hot
stove."
Two months later, Wright read
medical reports that the horse serum
was a quack remedy. He suffered an
immediate relapse. "Don't believe
what you read in the papers," the
doctor told Wright. Then he injected him with what he
said was "a new super-refined double strength" version
of the drug. Actually, it was water, but again, the
tumor masses melted.
Wright was "the picture of health" for another two
months -- until he read a definitive report stating
that Krebiozen was worthless. He died two days later.
Doctors who know this story dismiss it as one of those
strange tales that medicine cannot explain. The idea
that a patient's beliefs can make a fatal disease go
away is too bizarre.
But now scientists, as they learn that the placebo
effect is even more powerful than anyone had been able
to demonstrate, are also beginning to discover the
biological mechanisms that cause it to achieve results
that border on the miraculous. Using new techniques of
brain imagery, they are uncovering a host of biological
mechanisms that can turn a thought, belief or desire
into an agent of change in cells, tissues and organs.
They are learning that much of human perception is
based not on information flowing into the brain from
the outside world but what the brain, based on previous
experience, expects to happen next.
Placebos are "lies that heal," said Dr. Anne
Harrington, a historian of science at Harvard
University. A placebo, Latin for "I shall please," is
typically a sham treatment that a doctor doles out
merely to please or placate anxious or persistent
patients, she said. It looks like an active drug but
has no pharmacological properties of its own.
Until fairly recently, nearly all of medicine was based
on placebo effects, because doctors had little
effective medicine to offer. Through the 1940's,
American doctors handed out sugar pills in various
shapes and colors in a deliberate attempt to induce
placebo responses.
Nowadays, doctors have real medicines to fight disease.
But these treatments have not diminished the power of
the placebo.
Doctors in Texas are conducting a study of arthroscopic
knee surgery that uses general anesthesia in which
patients with sore, worn knees are assigned to one of
three operations -- scraping out the knee joint,
washing out the joint or doing nothing. In the
"nothing" operation, doctors anesthetize the patient,
make three little cuts in the knee as if to insert the
usual instruments and then pretend to operate. Two
years after surgery, patients who underwent the sham
surgery reported the same amount of relief from pain
and swelling as those who had had the real operations.
A recent review of placebo-controlled studies of modern
antidepressant drugs found that placebos and genuine
drugs worked about as well. "If you expect to get
better, you will," said Dr. Irving Kirsch, a
psychiatrist at the University of Connecticut who
carried out the review. His findings were met with a
great deal of skepticism.
And a recent study of a baldness remedy found that 86
percent of men taking it either maintained or showed an
increase in the amount of hair on their heads. But so
did 42 percent of the men taking a placebo.
Some studies are specifically designed to explore the
power of placebos rather than drugs. On Coche Island in
Venezuela, asthmatic children were given a sniff of
vanilla along with a squirt of medicine from a
bronchodilator twice a day. Later, the vanilla odor
alone increased their lung function, 33 percent as much
as did the bronchodilator alone.
And at Tulane University, Dr. Eileen Palace is using a
placebo to restore sexual arousal in women who say they
are nonorgasmic. The women are hooked up to a
biofeedback machine that they are told measures their
vaginal blood flow, an index of arousal. Then they are
shown sexual stimuli that would arouse most women. But
the experimenter plays a trick on the women by sending,
within 30 seconds, a false feedback signal that their
vaginal blood flow has increased. Almost immediately
they then become genuinely aroused.
Placebos are about 55 percent to 60 percent as
effective as most active medications like aspirin and
codeine for controlling pain, Kirsch said. Moreover,
placebos that relieve pain can be blocked with a drug,
naloxone, that also blocks morphine.
For a while, many scientists thought that placebos
might work by releasing the body's natural
morphine-like substances, called endorphins. But that
is not the only explanation, he said. While placebos
can act globally on the body, they can also have
extremely specific effects. For example, a study was
carried out in Japan on 13 people who were extremely
allergic to poison ivy. Each was rubbed on one arm with
a harmless leaf but were told it was poison ivy and
touched on the other arm with poison ivy and told it
was harmless. All 13 broke out in rash where the
harmless leaf contacted their skin. Only two reacted to
the poison leaves.
Studies have shown, time and again, that placebos can
work wonders. Like "real drugs," they can cause side
effects like itching, diarrhea and nausea. They can
lead to changes in pulse rate, blood pressure,
electrical skin resistance, gastric function, penis
engorgement and skin conditions. The question is, why?
Explanations of why placebos work can be found in a new
field of cognitive neuropsychology called expectancy
theory -- what the brain believes about the immediate
future.
Like classical conditioning theory (Pavlov's dogs
salivate at the sound of the bell), expectancy involves
associative learning. The medical treatments you get
during your life are conditioning trials, Dr. Kirsch
said. The doctor's white coat, nurse's voice, smell of
disinfectant or needle prick have acquired meaning
through previous learning, producing an expectation of
relief from symptoms. Each pill, capsule or injection
is paired with active ingredients, and later, if you
get a pill without active ingredients, you can still
get a therapeutic effect, he said.
Such conditioning shows how expectations are acquired,
Kirsch said. But it does not explain the strength and
persistence of placebo effects. These responses occur
almost instantly, with no apparent conscious thought,
and are therefore wired firmly into the brain, he said.
Response expectations are strong because the world is
filled with ambiguity. A long thin object seen in dim
light could be a stick or a snake. But it may not be
safe to take the time to find out. So people evolved a
mechanism to anticipate what is going to occur. This
expectation speeds the perceptual processing at the
expense of accuracy.
As in the outside world, people's internal states have
inherent ambiguity. That is why, when people in an
experiment were given a drug that produced a surge of
adrenaline, they interpreted the feeling as anger,
euphoria or nothing at all, depending on what they had
been told to expect.
Critics of alternative medicine say its enduring appeal
is explained by the placebo effect. When conventional
therapies fail to help chronic or poorly understood
conditions, the acupuncturist, homeopathist or
chiropractor steps into the breach with a potent belief
system ready-made to help the suffering patient. "If a
guy in a white coat or a guy dressed in feathers can
induce a patient's immune system to fight back, who is
to say which is better?" said Dr. Dan Molerman, a
medical anthropologist at the University of Michigan at
Dearborn.
Support for the expectancy theory emerged about 10
years ago, when many scientists realized how closely
the brain, the immune system and the hormone production
of the endocrine system are linked. Chronic stress sets
into motion a cascade of biological events involving
scores of chemicals in the body -- serotonin, cortisol,
cytokines, interleukins, tumor necrosis factor and so
on.
Such stress lowers resistance to disease and alters
gene expression. When people are under stress, wounds
tend to heal more slowly, latent viruses like herpes
erupt and brain cells involved in memory formation die
off. The precise molecular steps underlying all of
these changes have been mapped out.
But what about the opposite? Can a thought or belief
produce a chemical cascade that leads to healing and
wellness? Researchers studying placebos think the
answer is yes, and they offer several ways it might
work:
¶A placebo might reduce stress, allowing the body to
regain some natural, optimum level called health.
¶Special molecules may exist that help carry out
placebo responses. For example, a recent study found
that stressed animals can produce a valium-like
substance in their brains, but only if they have some
control over the source of the stress. People almost
certainly have similar brain chemistry.
¶Placebos may draw their power from the way the brain
is organized to act on what experience predicts will
happen next.
Dr. Marcel Kinsbourne, a neuroscientist at the New
School for Social Research in New York, explains it
this way: The brain generates two kinds of activation
patterns, which arise from networks of neurons firing
together. One type is set in motion by information
flowing into the brain from the outside world --
smells, tastes, visual images, sounds. At the same
time, the cortex draws on memories and feelings to
generate patterns of brain activity related to what is
expected to happen.
The top-down patterns generated by the cortex intersect
smoothly with the bottom-up patterns to inform us about
what is happening, Dr. Kinsbourne said. If there is a
mismatch, the brain tries to sort it out, without
necessarily designating one set of patterns as more
authoritative than another.
The expectations that result are internally generated
brain states that can be as real as anything resulting
purely from the outside world. For example, recent
experiments with monkeys show that if they expect a
reward like a sip of apple juice, cells in their brains
fire 20 to 30 seconds before they actually receive it.
In other words, expectancies are embedded in the
brain's neurochemistry.
"We are misled by dualism or the idea that mind and
body are separate," said Dr. Howard Fields, a
neuroscientist at the University of California at San
Francisco who studies placebo effects. A thought is a
set of neurons firing which, through complex brain
wiring, can activate emotional centers, pain pathways,
memories, the autonomic nervous system and other parts
of the nervous system involved in producing physical
sensations, he said.
Morphine will alter brain patterns to reduce pain. So
will a placebo. Obviously, placebos have limits.
Wright's miraculous remission aside, most people cannot
think, hope or believe their way out of cancer or AIDS.
As Dr. Howard Spiro, a gastroenterologist at Yale
University, put it: Some diseases are unleashed with
the power of a firehose.
Others unfold at a trickle, and perhaps those are the
ones amenable to placebo effects.
"Enthusiasm of Doctor Can Give Pill Extra Kick"
By SANDRA BLAKESLEE -- October 13, 1998
Though some people respond more strongly to
placebos than others do, it seems that everyone
responds at some
time or other. And doctors seem to play a large role in
the degree of that response.
"The thing that trumps everything is the enthusiastic
physician," said Dr. Dan Molerman of the University of
Michigan.
For example, one study offered the same drug to
patients with identical symptoms, with one difference.
Some were told by their physicians, "This drug has been
shown to work," while others were told, "I am not sure
if this treatment will work -- let's just try it." The
first group of patients did much better, Molerman said.
"The physician is an agent for optimism and hope and a
great inducer of beliefs."
Physicians can even fool themselves. Years ago,
researchers carried out controlled studies of a drug
for angina or heart pain and found it was no better
than a placebo, Molerman said. Once doctors knew that,
its effectiveness fell.
While doctors and patients affect one another's
expectations, both are swept up into a wider context of
culture and biology, said Dr. David Morris, an adjunct
professor of medicine at the University of New Mexico
in Albuquerque. The brain circuits through which
placebos act, he said, are activated through the
experience of living in a particular culture.
To explore the importance of cultural context,
Molerman, in an analysis forthcoming in the journal
Medical Anthropology Quarterly, compared 122
double-blind placebo-controlled ulcer studies from all
over the world. Doctors used the same techniques, the
same drugs and the same placebo pills and studied an
image of the stomach lining before and after treatment
to see what worked. The drugs worked 75 to 80 percent
of the time, Molerman said, whereas the placebos worked
from zero to 100 percent of the time, depending on the
country. The placebo healing rate for ulcers in Germany
was 60 percent, almost double the world average of 36
percent, which is about where the United States fell.
But in Brazil, the mean placebo healing rate was a
startling 6 percent.
"I don't have hint of what is going on here," Molerman
said. "I can only say that cultural differences affect
ulcer treatments, even though ulcers are the same the
world over."
Copyright 1998 The New York Times Company |
