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Placebo Power

By John Soderlund


If you follow developments in the world of psychiatric medications, you may have noticed that the placebo effect is enjoying considerable favourable press of late. The placebo effect refers to the beneficial effect that patients experience when they receive a non-active treatment or sugar pill. The principle of including the little-respected placebo in the medical literature is to differentiate the effect of the "real" treatment, the active ingredients, from the effect of the good feelings that flow from being provided with the treatment during the trial.

The head-bone's connected to the knee-bone

While the placebo's impressive performance in clinical trials is old hat now, in early July a group of researchers told the world about their discovery of a powerful placebo effect in a most unusual area of medical research - arthroscopic knee surgery.

Arthroscopic knee lavage or debridement - a procedure in which osteoarthritic sufferers of knee pain have small amounts of cartilage or bone removed from the knee - was found to be no better than placebo surgery in a randomised controlled trial reported in the July 11 issue of the New England Journal of Medicine.

That the placebo fared so well in this study is hardly surprising, given the recent spate of good publicity it has enjoyed. More telling for the publicity drive of the placebo are the implications of the findings.

In the words of the study's senior author Nelda Wray: "The fact that the effectiveness of arthroscopic lavage or debridement in patients with osteoarthritis of the knee is no greater than that of placebo surgery makes us question whether the dollars spent on these procedures might not be put to better use."

And the numbers are rather telling. In the U.S. alone, more than 650,000 arthroscopic debridement or lavage procedures are performed annually, many for arthritis, at a cost of about $5,000 each. That equates to around $3.25 billion and compares to an estimated $130 million it would cost for the same number of knee pain sufferers to visit and be given a reasonably convincing placebo surgical treatment.

Says Wray: "We have shown that the entire driving force behind this billion dollar industry is the placebo effect. The health care industry should rethink how to test whether surgical procedures, done purely for the relief of subjective symptoms, are more efficacious than a placebo."

Notwithstanding the good showing that the placebo earned in the trials, there appear to be no further plans to put it into commercial production or to recommend its future use for knee problems. Because, one must assume, the placebo, being an invisible and little understood phenomenon, is not something which, despite its theatrical prowess, has earned the respect of the scientific, measurement-based tenets upon which the medical industry is built.

No questions are posed about which active ingredients in the placebo cocktail are the ones which make the difference. No follow-up studies are designed to understand how a couple of small but clinically non-intrusive cuts around the knee area can make an arthritis sufferer feel less pain.

This stands in stark contrast to the fact that, when a drug outdoes the placebo in a similar controlled study, it is sure to be put into commercial production and marketed as a scientifically validated and effective treatment, approved by the relevant medical authorities.

No justice for the placebo

No doubt, the FDA would protest that the placebo would have to perform better than second best to earn more medical respect. But how close does it have to come?

Timothy Walsh, a psychiatrist at Columbia University, recently released results of a study which suggests that the effectiveness of placebos has grown significantly over the past two decades. A greater percentage of control group participants improve on placebos during trials of antidepressants in 2000 than was the case in 1981, he said.

And Washington Post staff writer Shankar Vedantam concluded in a lengthy and less equivocal article in May on the grim race between the placebo and antidepressants:

"After thousands of studies, hundreds of millions of prescriptions and tens of billions of dollars in sales, two things are certain about pills that treat depression: Antidepressants like Prozac, Paxil and Zoloft work. And so do sugar pills."

He cited a recent analysis which found that in the majority of trials conducted by drug companies in recent decades, sugar pills have done as well as-or better than-antidepressants.

Cases in point include a large study reported in April this year, which pitted the herbal remedy St. John's wort against Zoloft, one of the most widely prescribed antidepressants. St. John's wort effected clinically significant improvements in 24 percent of the depressed people who received it, and Zoloft was effective in 25 percent. But the placebo was found to be effective in 32 percent of its experimental subjects.

As Vedantam noted, the confounding and controversial findings do not mean that antidepressants do not work. But they do raise the possibility that the effects of antidepressant medications are being overblown and that the people who dispense the drugs and the manner in which they are dispensed may be as or more effective than the drugs themselves. In short, that the placebo may be more responsible for the improvement of depressives than the drugs themselves.

Vedantam noted that as the number of doctor visits for depression rose from 14 million in 1987 to almost 25 million last year, medications were prescribed for nine out of 10 patients, according to a study published in May.


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