According to the
American Cancer Society:
Even though placebos do not act on the disease, they seem to have an effect in about 1 out of 3 patients. A change in a person's symptoms as a result of getting a placebo is called the placebo effect. Usually the term "placebo effect" speaks to the helpful effects of a placebo in relieving symptoms. This effect usually lasts only a short time, and is thought have something to do with the body's own chemical ability to briefly relieve pain or certain other symptoms.
The BBC reported on
a study of the placebo effect that demonstrated its power:
They showed the benefits of painkillers could be boosted or completely wiped out by manipulating expectations. The study, published in Science Translational Medicine, also identifies the regions of the brain which are affected.
Heat was applied to the legs of 22 patients, who were asked to report the level of pain on a scale of one to 100. They were also attached to an intravenous drip so drugs could be administered secretly.
The initial average pain rating was 66. Patients were then given a potent painkiller, remifentanil, without their knowledge and the pain score went down to 55. They were then told they were being given a painkiller and the score went down to 39. Then, without changing the dose, the patients were then told the painkiller had been withdrawn and to expect pain, and the score went up to 64.
So even though the patients were being given remifentanil, they were reporting the same level of pain as when they were getting no drugs at all.
And of course, there's the same problem with
placebo effect in anti-depressant therapy:
With antidepressant drug trials, the placebo effect is high enough to cause a full half of these studies to end in failure, which has set off fierce debate over whether an antidepressant is little more than a placebo with side effects. The focal point of the controversy are two studies by Irving Kirsch PhD of the University of Connecticut:
A meta-analysis of nineteen nineteen double-blind antidepressant trials published in the American Psychological Association's online publication, Prevention and Treatment (Guy Sapirstein PhD of Westwood Lodge Hospital, Needham, MA, co-author) in 1998 caused an uproar in professional circles when it was revealed that the placebo effect accounted for a mind-boggling 75 percent of an antidepressant's result - any antidepressant, you name it.
Four years later, the July 2002 Prevention and Treatment published another study by Dr Kirsch that analyzed the FDA database of 47 placebo-controlled short-term clinical trials involving the six most widely prescribed antidepressants approved between 1987 and 1999. These included "file drawer" studies, ie trials that failed but were usually never published.
What Dr Kirsch and his colleagues found was that 80 percent of the medication response in the combined drug groups was duplicated in the placebo groups, and that the mean difference between the drug and placebo was a "clinically insignificant" two points on both the 17-item and 21-item Hamilton Depression Scale, regardless of the size of the drug dose. The placebo factor ranged from a high of 89 percent for the Prozac response, according to the study, and a low of 69 percent for the Paxil response. In four trials, the placebo equaled or achieved marginally better results than the drug. In the nine expert commentaries published with the study, none of the commentators disputed the study's main findings.
So my question is this:
If the placebo effect of anti-depressants and painkillers is accepted with little fuss, why the sturm und drang around these bracelets? My impression is that it's simply a cultural thing - the former are seen as side effects of a "respectable" scientistic endeavour, while the latter are seen (by those same scientists that support the former view) as fraud. The effect is exactly the same in each case, just in the case of the bracelets it's being delivered by guys in blue jeans instead of lab coats
In the case where the effect of an anti-depressant is shown to be due to the placebo effect, aren't the scientists wo brought it to market guilty of effectively "selling bracelets to unsuspecting dupes"?