So... here. As promised in Pensées from Moi.
Original publishing date: April 27, 2010.
Original Title: Placebopathy
World Homeopathy Awareness week is long over, without my having been able to write as much as I wanted about it. Sigh. Often life gets in the way of enjoyment.
However, it works the other way, too. This morning, my eyes got caught by an interesting Op Ed piece in the New York Times, titled "Mind Over Meds", written by Daniel Carlat, a practising psychiatrist, an associate clinical professor of psychiatry at Tufts University School of Medicine and the publisher of The Carlat Psychiatry Report. He laments how the increased availability of psychiatric medications have eroded the practice of good, old-fashioned psychiatric counselling or psychotherapy, when such counselling can be - in certain situations - just as effective as, or serve as an essential adjunct to, psychoactive pharmacotherapy, especially in patients who don't respond well to psychiatric medications. He also touches upon how health insurance companies in the US have substantially influenced this shift in therapeutic paradigms.
But that's not what piqued my interest. In the article, Dr. Carlat makes an observation:
But over the past few years, research studies have shown that ... medications themselves often work through the power of placebo. In one study, for example, researchers did a meta-analysis of studies submitted by drug companies to the F.D.A. on seven new antidepressants, involving more than 19,000 patients. It turned out that antidepressants are, indeed, effective, because on average patients taking the pills showed a 40 percent drop in depression scores. But placebo was also a powerful antidepressant, causing a 30 percent drop in depression scores.Consider the impact of this last statement. This means that - when considering a drop in the depression score as an endpoint - a placebo is three-quarters as effective as the antidepressants medication, or that 3/4th of the patients' response to the antidepressants may actually be due to the placebo effect.
He indicates that "Nobody knows exactly how the mysterious placebo effect works, but it is clear that it has impacts on the brain that can be seen as clearly as medication effects", and goes on to quote a pain study from the University of Michigan (Ref: The Journal of Neuroscience, August 24, 2005, 25(34):7754-7762).
In this 2005 study, jaw muscle pain was induced in volunteer subjects by injecting normal saline. The subjects were subsequently led to believe that they would be given an intravenous infusion of a painkiller, when in reality they received only further normal saline. Despite the placebo, they reported marked improvement (i.e. reductions in pain intensity, in the sensory and affective qualities of the pain, and in the subjects' negative emotional states). A positron emission tomography (PET) scan showed that the endogenous opioid (endorphin) system was activated in both higher-order and sub-cortical brain regions of the subjects. The expectation of effective treatment by the patients modulated their brains' handling of the physiological stress.
Dr. Carlat surmises that this must be the mechanism by which even the psychiatric placebos work. His focus is, as a matter of course, on psychiatric issues. But I was struck by the thought of how closely this resembles the situation with homeopathy!
Although Homeopathy has never been able to stand up to the scrutiny afforded by randomized clinical trials, in the European and Asian countries where it is available as a choice of medicine, anecdotes abound as to how effective it is. I don't even have to look far; my dear old parents, to this day, will absolutely insist that a variety of their ailments, of an allergic, respiratory or gastrointestinal nature, have been ameliorated or kept in abeyance by homeopathic nostra. Arguing with them about the implausibility of homeopathic anything having a measurable physiological effect is, consequently, useless.
I am, therefore, left concluding that homeopathy, like religion, is a cultural phenomenon, and gaining any benefit from it requires an absolute faith in its efficacy, a kind of devotion that would trigger the endorphin system, essentially tricking the brain into believing that the body is getting better; anecdotes of homeopathy's efficacy hinge upon this crucial fact.
Of course, as with any placebo, the process is uncertain, non-regulatable, spontaneous and random in way that can never gain a foothold in proper, evidence-based medicine. It also means that if there is a serious underlying organic defect, the placebo will not work, and insistence on using homeopathic remedies has a great potential to bring harm to the patient (Examples abound). This is why I find it unconscionable that the US FDA doesn't hold homeopathic products to the same standards as other drugs, allowing the former to be sold from health-food stores, pharmacies, offices of homeopaths, by mail- and Internet-order.
Original Comments
Just a brief note on the placebo effect: There may be a 30% drop in measurements of depression, but you can't conclude that an individual, who responded positively, will continue to do so. In my experience as a physician, placebo effects are highly variable and usually don't last. Some patients do well year after year on one specific drug and another patient, trying one drug after the other, may find that each one stops working after a few weeks or months. If you aim, for example for short-term pain relief, a placebo injection may work, but it will not continue to do so for chronic pain.