January 4, 2012

SOMETIMES, NOTHING IS A REAL COOL CURE:

Placebo Effect Stronger Than We Thought?: Double-blind trials have long been considered the gold standard to determine drugs' effectiveness. Do we need to rethink that assumption, given the power of the placebo effect? (Beryl Lieff Benderly, 1/04/12, Miller-McCune)

There's one more treatment that seems to have, in some cases, eased symptoms of Parkinson's disease: the administration of placebos. How should such results be understood?

The prevalent assumption of researchers has long been that placebo treatments are inert, and that "placebo and treatment are independent, and that there's no interaction effect between" them, Cohen says. From this idea flows the conclusion that any sign of improvement among patients receiving a placebo must indicate the presence of some kind of experimental bias, by which scientists mean some factor that systematically distorts experimental results in favor of a particular conclusion. This logic served medical science well for many decades and has accounted for huge advances in both knowledge and cures. In cases of treatments intended to cure infections, kill microbes, or serve as vaccines, for example, inactive controls -- placebos -- can reveal whether or not a treatment really works.

But suppose the assumption that the control is inert -- that it has no effect and is independent of any results from the treatment being tested -- is not always correct. The human brain doesn't act like infectious microbes or research animals that cannot, so far as is known, believe that a treatment will make them well. Nor, as healers have understood for centuries, are positive changes from inactive treatments necessarily bogus. Rather, a placebo effect, even if caused by a well-intentioned sugar pill, can bring real improvement in a human patient's condition.

This has been well accepted since 1955, when Harvard anesthesiologist Henry Beecher published an influential article in The Journal of the American Medical Association called "The Powerful Placebo." An incident of benevolent deception that he had witnessed during World War II inspired Beecher to undertake postwar research on the placebo effect. He had seen a nurse tell a wounded soldier he was getting a shot of morphine when all she had to give him was salt water. The man's severe pain abated nonetheless. After the war, Beecher studied existing research and became convinced that about 35 percent of patients showed improvement that could be attributed to placebos. The news riveted the medical world.

In a 2010 article in The Lancet, Damien G. Finniss of the University of Sydney Pain Management and Research Institute, and co-authors, wrote, "Placebo effects are genuine psychobiological phenomenon" that occur because of "the overall therapeutic context" and can happen both in the laboratory and the clinic. Research well supports the fact that, unlike experimental animals, people given placebos hope or expect that treatment will make them better, but recent findings also show that there is a connection between Parkinson's and placebo use that is even deeper than hope or expectations.

"In Parkinson's disease ... the placebo effect is associated with release of endogenous dopamine" -- the very neurotransmitter in short supply because of the illness -- in two areas of the brain, write Sarah C. Lidstone and colleagues at the Pacific Parkinson's Research Centre, in the Archives of General Psychiatry. It's possible that the placebo effect may act on the very brain pathways involved in the disease.

Such findings about placebos and dopamine in Parkinson's patients indicate that old assumptions need revision, argue Finniss and other researchers. The late J. Stephen Fink, a Parkinson's researcher who chaired the department of neurology at Boston University School of Medicine, for example, noted in an article on the American Parkinson's Disease Association website that the gains that placebo recipients experience in Parkinson's trials may even result in part from "actual physiological changes in the damaged brain dopamine nerve cells."

These developments require researchers to "reconsider placebos and placebo effects," looking not at what they can't accomplish, but at what they are "actually doing to the patient," write Finniss and co-authors. A paradox lies at the center of the traditional concept, they note, because an inert agent, by definition, can't have an effect. Therefore, the role that a patient's expectations might have in the results of a trial needs to be understood as an important factor. Could placebo responses possibly trigger or even enhance the effects of treatments? The reconsideration that Finniss and co-authors are advocating could give placebo reactions a specific role in treatment techniques and even "encourage the use of treatments that stimulate placebo effects," they write.

It's a good way to cut rising medical costs too.

Posted by at January 4, 2012 6:51 PM
  

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