(January 4, 2008 - Insidermedicine) Nearly half of Chicago internists who responded to a questionnaire admitted to having given patients a placebo on at least one occasion in the past, according to a study published in the Journal of General Internal Medicine.

Here are some facts about placebos:

•    A placebo is a "treatment" that has no known intrinsic effect on the body. A common example of a placebo is a sugar pill that is made to look just like a real medication. Placebos are commonly used in studies testing the effects of drugs so that participants do not know whether they are receiving active medication.

•    The placebo effect refers to a phenomenon in which a placebo has an effect on a person's condition simply because that person expects there to be an effect.

•    Currently, experts disagree on whether it is ethical for physicians to use placebos for treatment without informing patients.

Researchers from the University of Chicago sent questionnaires about placebo use to nearly 500 local internists. Nearly half of the internists completed and returned the questionnaire.

Overall, 45% of the internists reported that they had given placebos to one or more of their patients in the past. Only 4% of these physicians indicated that they had specifically told these patients they were receiving a placebo. Instead, the doctors variously described the placebo as "a substance that may help but will not hurt", "a medication", or "a medication with no specific effect."

Today's research highlights the fact that many physicians do prescribe placebos to their patients, at least on occasion. The study authors conclude that use of placebos and other unproven treatments in medical practice should be better recognized and further discussed.

For Insidermedicine in Depth, I'm Dr. Susan Sharma.