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That placebo punch

Scientists are learning to harness the power of sham treatments -- without the trickery.

December 12, 2005|Emily Singer | Special to The Times

WHEN Haley Mack of Long Beach participated in a clinical trial testing new treatments for depression last November, she was told she would get either a real medicine or a placebo. But Mack was sure she was taking the real pill. She could do things that had been very difficult since she was diagnosed with clinical depression -- she could shower and get dressed, and she actually looked forward to going to the clinic.

"It had been difficult to look forward to things at all," she says.

At the end of the trial, Mack was surprised to find out she had, in fact, been taking a fake pill. "My boyfriend joked . . . that I should go back on the placebo," she says. "He thought I seemed much better."

Mack's boyfriend may have a point. Sham treatments, medical science is learning, can have a powerful effect on health. Researchers have found that administering sugar pills and saline injections can ameliorate pain, depression and anxiety. Such treatments can reduce tremors and other symptoms in Parkinson's patients, lower blood pressure in those with hypertension and open up airways in people who suffer from asthma.

Researchers have even shown that sham knee surgery can alleviate arthritis pain and sham chest surgery, angina pain.

Now doctors want to harness that power as a tool for treatment -- without resorting to trickery.

This is not as far-fetched as it sounds. Scientists are learning more about the response of the brain to placebos and about the various elements of treatment that help a patient feel better.

Say you go to the doctor with a headache, and your doctor secretly gives you a candy mint rather than an aspirin. That fake pill gives you an expectation that you will feel better -- and the so-called placebo effect kicks in, and you do. If that were \o7all\f7 the placebo effect was about, doctors would be stuck. Deceptively prescribing a candy instead of medicine to a patient in pain is not considered ethical behavior.

Luckily, other aspects of the doctor's visit -- such as the whole doctor-patient interaction -- play a role in placebo healing as well.

"The response to placebo is not just a response to an inactive pill, it's a response to the entire treatment situation," says Dr. Walter Brown, a psychiatrist at Brown University in Rhode Island. "It's everything: going to an expert, talking about the problem, getting a diagnosis and a plausible treatment."

Researchers are studying the best ways to capitalize on these cues.

The modern study of the placebo effect started in 1955, with a scholarly paper by Harvard physician Dr. Henry Beecher, titled "The Powerful Placebo." Beecher reviewed 15 studies of conditions such as pain, anxiety and seasickness and concluded that, on average, about one-third of the people in the studies benefited from sham medicine. More recent studies have reported sometimes greater, sometimes lower, percentages of responders, depending to some extent on the medical condition.

Debates about placebos continue to simmer. Some scientists argue that the placebo effect doesn't exist or has been greatly exaggerated -- that the effects of sham medicines can be explained away by, for example, faulty statistics or health improvements that would have occurred anyway.

Other scientists suggest (also controversially) that the placebo's clout can be impressively strong. A 1998 analysis of 19 clinical trials of antidepressants concluded that nearly half of these drugs' efficacy is linked to the placebo effect.

Brain imaging studies have lent credence to the placebo effect as a real physiological phenomenon. For example, in two studies published in 2002, clinically depressed patients who responded to placebos showed dramatic changes in activity in the same areas of the brain that respond to antidepressants: the prefrontal cortex and the cingulate cortex. (The nature of these changes wasn't identical in those who took medicine versus placebo.)

Other imaging studies have shown that the prefrontal cortex is active during the placebo response. This is the same part of the brain that lights up when you try to make yourself feel better or worse -- rather as if the placebo response is similar to your ability to cheer yourself up, to regulate your mood if you've had a bad day by telling yourself that things aren't so terrible.

"Things like pain don't just happen to you; your brain has to interpret the meaning and value to you," says Tor Wager, a psychologist at Columbia University in New York and author of some of the brain-scanning research. "Those circuits are partly under our control. The placebo is a way to [control] it beyond what we can do voluntarily."

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