When placebos do harm

[Susan L Gawarecki <loc@icx.net>]

I've often thought that there is a "nocebo" effect associated with 

exposure to hazardous substances and radiation, even below levels known 

to be safe.



--Susan Gawarecki



When placebos do harm

If you think those side effects you're feeling are a result of your 

medication ... you may be wrong

BY EARL LANE

NEWSDAY WASHINGTON BUREAU

http://snipurl.com/4o5o

February 23, 2004



SEATTLE -- While researchers have tried to understand why some patients 

feel better after receiving a sham pill, a placebo, rather than an 

active drug, relatively little attention has been paid to the placebo's 

evil twin: the nocebo.



Dr. Arthur Barsky, a professor of psychiatry at the Harvard Medical 

School, said recently the nocebo effect occurs when patients experience 

negative symptoms, such as headache, fatigue and dizziness, after taking 

an inert substance they believe is an active drug.



A placebo, Latin for "I will please," is often given to one group of 

subjects in a clinical trial as a way to judge the true benefit of the 

active medication being given to a second group of patients. The sham 

pill itself can sometimes produce improvement in symptoms for reasons 

that are still largely a mystery.



A placebo control group is important in a clinical trial, according to 

Barsky, because it allows the researchers to determine how much of the 

overall improvement in a group of patients is due to the biological 

action of the drug compared with the effects of the placebo. In 

randomized clinical trials, neither the treating doctors nor the 

patients are told who gets the active drug and who gets the dummy pill.



The nocebo effect



While the potentially beneficial effects of placebos have been discussed 

widely, Barsky said, an analysis he and several colleagues did in 2002 

found that about one-quarter of patients taking placebos in research 

studies reported adverse side effects. When the patients were actively 

questioned, the incidence of complaints was even higher - as much as 71 

percent in one study.



When a sham pill provokes a negative reaction it is called a nocebo, 

Latin for "I will harm." The nocebo effect is not trivial, Barsky said, 

and may help explain some side effects that are experienced by people 

who are taking active medications.



"Clinically, it's a very important issue," he said during a meeting here 

of the American Association for the Advancement of Science.



In one typical study of an active drug, Barsky said, 11 percent of side 

effects were clearly related to the biological action of the drug; 69 

percent were possibly or probably related to that action; and 20 percent 

were not related. Those unrelated side effects tend to be vague and 

nonspecific, he said, much like the nonspecific symptoms that have been 

reported by patients receiving a sham pill.



Barsky notes there is a reservoir of ill-defined distress in the 

healthy. "Most of us have symptoms all the time," he said, mild 

infirmities such as headache, fatigue and drowsiness. He argues that 

patients can seize on such symptoms and misattribute them to the drug 

they are taking. Similarly, adverse side effects associated with a dummy 

pill also may be drawn from the reservoir of bodily symptoms that a 

patient now can attribute to a presumed agent.



The expectations game



The nonspecific side effects can have serious consequences, Barsky said. 

In controlled studies, they can be serious enough to cause some people 

to drop out of the trial. Also, patients receiving a placebo who feel 

side effects may conclude they are on the active drug. That can increase 

expectation they are going to get better. The result, he said, will be 

to diminish the treatment effect of the drug. The gap in response 

between the drug and placebo will be narrowed, he said.



Expectations and prior experiences can help account for the nocebo 

effect, Barsky said. Patients who expect distressing side effects before 

taking a medication are more likely to report having them.



The research literature also suggests that patients with characteristics 

such as anxiety, depression and a heightened awareness of their bodies 

also are more likely to develop side effects to an active drug or to 

experience nocebo symptoms.



Even the color matters



Even the physical characteristics of the pill itself, such as the size, 

color and shape, may influence symptoms, according to Barsky. In one 

study, volunteers taking blue placebos reported more drowsiness than 

those taking pink placebos.



Although the term nocebo was used in a medical report as far back as 

1961, the effect is little studied, according to Barsky. Doctors should 

be aware, he said, that troublesome side effects reported by patients 

may not necessarily result from the pharmacological action of the drug.



Physicians and researchers should ask whether patients have had prior 

bad experiences with drugs or consider themselves especially sensitive 

to drugs. Patients should be reassured that the side effects, while 

bothersome, are not medically dangerous.

-- 

.....................................................

Susan L. Gawarecki, Ph.D., Executive Director

Oak Ridge Reservation Local Oversight Committee

102 Robertsville Road, Suite B, Oak Ridge, TN 37830

Toll free 888-770-3073 ~ www.local-oversight.org

.....................................................





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