From Weight Loss to
Fertility, New Legitimacy For 'Fake' Treatments
Wall
Street Journal, In the Lab, January 3, 2012
Say "placebo
effect" and most people think of the boost they may get from a sugar pill
simply because they believe it will work. But more and more research suggests
there is more than a fleeting boost to be gained from placebos. A particular mind-set or belief about one's body or health may lead to improvements in disease symptoms as well as changes in appetite, brain chemicals and even vision, several recent studies have found, highlighting how fundamentally the mind and body are connected.
It doesn't seem to matter whether people
know they are getting a placebo and not a "real" treatment. One study
demonstrated a strong placebo effect in subjects who were told they were
getting a sugar pill with no active ingredient.
Placebo treatments are sometimes used in
some clinical practices. In a 2008 survey of nearly 700 internists and
rheumatologists published in the British Medical Journal, about half said they
prescribe placebos on a regular basis. The most popular were over-the-counter
painkillers and vitamins. Very few physicians said they relied on sugar pills
or saline injections. The American Medical Association says a placebo can't be
given simply to soothe a difficult patient, and it can be used only if the
patient is informed of and agrees to its use.
Researchers want to know more about how the
placebo effect works, and how to increase and decrease it. A more powerful,
longer-lasting placebo effect might be helpful in treating health conditions
related to weight and metabolism.
Hotel-room attendants who were told they
were getting a good workout at their jobs showed a significant decrease in
weight, blood pressure and body fat after four weeks, in a study published in
Psychological Science in 2007 and conducted by Alia Crum, a Yale graduate
student, and Ellen Langer, a professor in the psychology department at Harvard.
Employees who did the same work but weren't told about exercise showed no
change in weight. Neither group reported changes in physical activity or diet.
Patients in a recent study were treated with
placebos for an induced asthma attack. They reported feeling just as good as
when they received an active treatment with albuterol.
Another study, published last year in the
journal Health Psychology, shows how mind-set can affect an individual's
appetite and production of a gut peptide called ghrelin (GREL-in), which is
involved in the feeling of satisfaction after eating. Ghrelin levels are
supposed to rise when the body needs food and fall proportionally as calories
are consumed, telling the brain the body is no longer hungry and doesn't need
to search out more food.
Yet the data show ghrelin levels depended on
how many calories participants were told they were consuming, not how many they
actually consumed. When told a milkshake they were about to drink had 620
calories and was "indulgent," the participants' ghrelin levels fell
more—the brain perceived it was satisfied more quickly—than when they were told
the shake had 120 calories and was "sensible."
The results may offer a physiological
explanation of why eating diet foods can feel so unsatisfying, says Ms. Crum,
first author on the study. "That mind-set of dieting is telling the body
you're not getting enough."
Studies across medical conditions including
depression, migraines and Parkinson's disease have found that supposedly inert
treatments, like sugar pills, sham surgery and sham acupuncture, can yield
striking effects. A 2001 study published in Science found that placebo was
effective at improving Parkinson's disease symptoms at a magnitude similar to
real medication. The placebo actually induced the brain to produce greater
amounts of dopamine, the neurotransmitter known to be useful in treating the
disease.
At times, a weaker placebo effect might be
desired. In trials of experimental drug treatments for dementia, depression and
other cognitive or psychiatric conditions, where one patient group takes medication
and the other takes a sugar pill, it can be difficult to demonstrate that the
medicine works because the placebo effect is so strong.
With depression, an estimated 30% to 45% of
patients—or even more, in some studies—will respond to a placebo, according to
a review published in December in Clinical Therapeutics. An additional 5% of
patients were helped by an antidepressant in cases of mild depression, and an
additional 16% in cases of severe depression. (The clinically meaningful cutoff
for additional benefit was 11%.)
Fertility rates have been found to improve
in women getting a placebo, perhaps because they experience a decrease in
stress. A recent randomized trial of women with polycystic ovarian syndrome
found that 15%, or 5 of 33, got pregnant while taking placebo over a six-month
period, compared with 22%, or 7 of 32, who got the drug—a statistically
insignificant difference. Other studies have demonstrated pregnancy rates as
high as 40% in placebo groups.
Ted Kaptchuk, director of Harvard's Program
in Placebo Studies and the Therapeutic Encounter, and colleagues demonstrated
that deception isn't necessary for the placebo effect to work. Eighty patients
with irritable bowel syndrome, a chronic gastrointestinal disorder, were
assigned either a placebo or no treatment. Patients in the placebo group got
pills described to them as being made with an inert substance and showing in
studies to improve symptoms via "mind-body self-healing processes."
Participants were told they didn't have to believe in the placebo effect but
should take the pills anyway, Dr. Kaptchuk says. After three weeks,
placebo-group patients reported feelings of relief, significant reduction in
some symptoms and some improvement in quality of life.
Why did the placebo work—even after patients
were told they weren't getting real medicine? Expectations play a role, Dr.
Kaptchuk says. Even more likely is that patients were conditioned to a positive
environment, and the innovative approach and daily ritual of taking the pill
created an openness to change, he says.
Do placebos work on the actual condition, or
on patients' perception of their symptoms? In a study published last year in
the New England Journal of Medicine, Dr. Kaptchuk's team rotated 46 asthma
patients through each of four types of treatment: no treatment at all, an
albuterol inhaler, a placebo inhaler and sham acupuncture. As each participant
got each treatment, researchers induced an asthma attack and measured the
participant's lung function and perception of symptoms. The albuterol improved
measured lung function compared with placebo. But the patients reported feeling
just as good whether getting placebo or the active treatment.
"Right now, I think evidence is that
placebo changes not the underlying biology of an illness, but the way a person
experiences or reacts to an illness," Dr. Kaptchuk says.
Placebo can be more effective than the
intended treatment. In a trial published in the journal Menopause in 2007, 103
women who had menopausal hot flashes got either five weeks of real acupuncture,
or five weeks of sham acupuncture, where needles weren't placed in accepted
therapeutic positions. A week after treatments ended, only some 60% of
participants in both groups reported hot flashes—a robust immediate placebo
effect. Seven weeks post-treatment, though, 55% of patients in the sham
acupuncture group reported hot flashes, compared with 73% in the real
acupuncture group.
Corrections & Amplifications
An earlier version of this article said that a study in the journal Health Psychology about appetite and the gut peptide ghrelin was published earlier this year.
An earlier version of this article said that a study in the journal Health Psychology about appetite and the gut peptide ghrelin was published earlier this year.
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