Wednesday, March 14, 2012

Playing With Our Minds: The Placebo Effect

When I was in Spain last summer, I came across a chain of stores called Happy Pills. The store sold candy in prescription like bottles with cute sayings affixed. I learned from store management that they had 4 stores and I happened across two of them which seemed to be busy. Not a fan of candy, I wondered what would be a better replacement. Placebos came to mind. Of course, most placebos are in fact inert sugar pills so nutritionally they are no better than candy, but when it comes to medical studies, that's a whole different story.

It wasn't their taste, look, or nutritional content that piqued my curiosity about using placebos. It's the fact that I come across numerous randomized double blind controlled studies that use a placebo pill, injection, or sham procedure as the control and that actually show symptom improvement for both groups of subjects, including those receiving the placebo.

Three interesting studies comes to mind. One involved the use of placebo against counseling for the treatment of Irritable Bowel Syndrome (IBS). Performed by the Program for Placebo Studies at Harvard, fascinatingly, the placebo users who were told they were being given a placebo still showed marked improvement in their IBS related symptoms.

In a second Harvard study, placebo was compared against saw palmetto for prostate symptoms and the saw palmetto reduced symptoms by 30% while placebo reduced symptoms by 31%.

In a third study looking at the effects of Human Chorionic Gonadotropin (HCG), the weight loss drug, placebo was administered in the form of injections. Both parties showed identical weight loss due to the accompanying low calorie diets.

So placebos clealry have clinical effectiveness. Why? Our minds are very susceptible to suggestion. The word placebo is a Latin word which means "I shall please." How apropos as that is what it seems to often do. In fact in 1811, placebos were defined as "any medicine adapted more to please than to benefit the patient."    

One could write a book about the placebo effect and in fact, Henry Beecher did in 1955 titled The Powerful Placebo. Since that time, there have been numerous studies, including a Cochrane Review of their effects.  They seem to be most effective in illnesses that are thought to involve some psychological elements such as pain, depression, chronic fatigue syndrome, and gastric disturbances. There is disagreement if placebos work for everyone and that debate rages on.  There are also medical ethical questions regarding their use, but even here there is no clear consensus. Sometimes the ingredients in a placebo, which are meant to be inert, can actually be responsible for negative effects which is called nocebo.  Some women even demonstrated withdrawal symptoms when taken off placebo for a hormone replacement trial.

There can be no doubt that the placebo effect is real in terms of subjective patient reporting of improved symptoms and therefore placebo use can be reasonably claimed to sometimes provide real clinical benefit under the right circumstances. Other times, placebos have shown no effect, particularly as related to objective measurements such as blood pressure.

Some doctors have been known to use placebos to fend off unreasonable requests from patients. For example, a doctor sees a patient with what he diagnoses to be a viral illness that will not respond to antibiotics.  The patient nevertheless insists on taking antibiotics. It has been reported that some doctors have resorted to using placebos in such a case. The ethics of doing so can be reasonably debated but such practice has been reported as high as 60% in some countries.

One of the biggest arguments used by supplement marketers is that even if supplements provide no physiological benefit, then perhaps they still provide some psychological benefit. This may be true, but I think it is a dangerous premise. Supplements are usually used in a preventive nature--to prevent disease.  Relying on supplements can lead one not to take proper care of one's health and therefor such logic can lead to dire consequences. Some describe this as the licensing effect in which the belief that supplements are protective leads one to engage in otherwise unhealthy behaviors such as eating poorly or excessively.

I think placebos have their place, but it's a case by case basis. I suspect they will be around for a long time and will continue to be widely used in medical studies. I'm also sure that someday, someone will open a retail shop specializing in placebos and will make lot of money off of unwary or bemused shoppers. That person will not be me.

1 comment:

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