Medicine's Humble Humbug

	"The placebo response doesn't just happen when you give someone a fake pill," says Harrington. "It always happens."

But Rennard ran his experiment in test tubes, not in human beings suffering from colds. Unlike a test tube, each person brings his or her own set of unique expectations, biases and motivations - both conscious and unconscious - to the experiment. As we saw throughout "The Wonder Pill," these subjective experiences can result in the powerful phenomenon called the placebo effect.

Scientists recognized the need to screen out the placebo effect - what they called the "risk of imagination" - as far back as the 18th century, according to Anne Harrington, a historian of science at Harvard University. In the 1780s, Franz Mesmer enchanted Parisian society with his theory of animal magnetism-the notion that illness results from disturbances in the body's natural electromagnetic field. Claiming that he could cure virtually any disease with magnets or magnetized objects, Mesmer demonstrated his abilities before large crowds, causing his patients to fall asleep, dance or convulse on command.

Mesmer's showmanship caused many to believe he possessed healing powers.

In 1784, King Louis XVI of France commissioned an investigation into Mesmer's claims. In what is sometimes described as the first placebo-controlled trial, the commission - led by Benjamin Franklin and French chemist Antoine Lavoisier - put animal magnetism to the test. The commission replicated one of Mesmer's sessions, asking subjects to hug allegedly curative magnetized trees. As expected, the subjects swooned and reacted strongly to the trees - but the trees were never magnetized at all. The subjects' responses were clearly induced by something else - either dishonesty or the placebo effect.

According to Harrington, this trial makes it clear to Franklin and other scientists of the day that "human imagination is a very potent part of the clinical context. Not just when you're dealing with odd or suspect forms of therapy," she says. "But also in the most mainstream of clinical situations."

The best doctors saw the placebo effect as part of the art of medicine and willingly made use of their patients' capacity to use their imaginations to heal themselves.

"It was an open secret, and some publications talk ambivalently about the fact that doctors made use of it," says Harrington. "An article in the late 1930s talked about the placebo as 'medicine's humble humbug.'

Psychologist Robert Ader pioneered the field of psychoneuroimmunology, or harnessing the placebo effect to cure illness, when he demonstrated the immune system could be conditioned to respond to inert compounds.

But the placebo effect fell out of fashion after World War II with the rise of the pharmaceutical industry. Clinical research demanded more rigorous means of determining whether new medications are worth the investment required to bring drugs to market.

"And here what had been an advantage if you were a clinician becomes a distinct disadvantage if you're a researcher," says Harrington. "Because if you want to test whether or not a drug objectively works you don't want your patients to have all these subjective reactions to just the very act of being given a treatment regardless of what's inside it."

As medical research became increasingly evidence-based, the randomized clinical trial evolved to screen the placebo effect out of the data and became the gold-standard research tool. With it, medical science made incredible breakthroughs that have added years to life span in industrialized nations. But the randomized trial also made some scientifically valid questions harder to ask, such as what "real" effects can be caused by subjective things -sugar pills or empathetic doctors - and how.

"One of the things that needs to be appreciated is that the placebo response doesn't just happen when you give someone a fake pill," says Harrington. "It always happens."

By the 1970s, new technology invited the placebo effect back into the discussion when research revealed that the brains of people given sham pain medicine secreted actual pain-blocking chemicals.

"That was a real blockbuster," says Harrington. "Something we called fake was producing something real. It led to the feeling that maybe the placebo effect is one way that the body turns on its own self-healing mechanism."

As studies such as Andrew Leuchter's and Jonathan Stoessl's document measurable placebo effects, researchers like Ted Kaptchuk study the phenomenon itself. The research asks not how fake things can effect real things, but how different kinds of social or environmental cues can trigger the body's own healing processes. Human sociability comes into focus.

"We're probably exquisitely attuned to responding to help from other human beings," says Harrington. "There are medicine men and healers in every society. All they have is themselves to offer, and yet, they're very much valued members of the community. That must mean something. Probably one of the most potent triggers to self-healing that human beings possess is another human being."

Web Site:
The Art of Renaissance Science
Visit this illustrated site to learn more about Galileo and the connections between art and science in the Renaissance.

Images: "Man and the Unknown"; University of Rochester

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