Three weeks ago, I mentioned in a post that the week of October 7 to 14 was declared by our very own United States Senate to be Naturopathic Medicine Week, which I declared unilaterally through my power as managing editor of Science-Based Medicine (for what that’s worth) to be Quackery Week. One wonders where the Senate found the time to consider and vote for S.Res.221, which reads:
S.Res.221 – A resolution designating the week of October 7 through October 13, 2013, as “Naturopathic Medicine Week” to recognize the value of naturopathic medicine in providing safe, effective, and affordable health care.
I know, I know, it probably took all of five minutes to consider and vote for this, thanks to Sen. Barbara Mikulski (D-MD), who sponsored it. In any case, as October 7 approached, I thought about how I could keep my promise to blog about naturopathy this week, and I came up with a way to do it. It’s a bit roundabout, but I think it fits. The idea derives from a discussion I was having a while back about one of my “favorite” hospitals, namely the Cancer Treatment Centers of America, in which a colleague of mine questioned why there were so many CTCA ads on NPR and why CTCA is sponsoring shows on PBS such as the upcoming The Emperor of All Maladies by Ken Burns. Although I can’t wait to see this particular series, I am a bit worried that the infiltration of quackademic medicine will make an appearance, given that CTCA is a major sponsor. (more…)
Science journalist Sharon Begley wrote a recent piece in The Saturday Evening Post about Placebo Power. The piece, while generally better than the typical popular writing on placebos, still falls into the standard placebo narrative that is ubiquitous in the mainstream media. The article is virtually identical to a dozen other articles I have read on placebo effects in the popular press, and most significantly fails to even question that narrative.
Begley is generally one of the better science journalists, although I have had my disagreements with her – specifically over her attitude toward the relationship between skeptics and the media. She seems to have a distorted and negative view of skeptics and does not think that the media can or should help us in our “debunking crusade.” (The term itself speaks of a fundamental misunderstanding of the modern skeptical movement.)
I have also parted ways with Begley over her view of the relationship between science and medicine. She seems to have a fairly negative view of doctors, fueled in part by her imperfect grasp of medical science. This is the risk with even the best lay science journalists – science is often complex and it is difficult to master the nuances if you are not an expert and steeped in the evidence and the community. Further there is a tendency for people in general (including journalists) to go along with an appealing and available narrative. (For journalists those narratives that are appealing are the ones that make good headlines.) These shortcomings are present throughout her recent article on placebos.
A study recently published in PLOS one (Catechol-O-Methyltransferase val158met Polymorphism Predicts Placebo Effect in Irritable Bowel Syndrome) purports to have found a gene variant that correlates strongly with a placebo response in irritable bowel syndrome (IBS). The study is small and preliminary, but the results are interesting and do raise important questions about placebo responses.
Researchers are increasingly trying to tease apart the various components of “the placebo effect.” In reality we should use the term “placebo effects” as it is demonstrably multifactorial. “The placebo effect” really refers to whatever is measured in the placebo arm of a clinical trial – everything other than a physiological response to an active intervention. Within that measured response there are many potential factors that would cause an outcome from a fake treatment to be different from no treatment at all. These include statistical effects like regression to the mean and the natural course of symptoms and illness, reporting bias on the part of the subject, and a non-specific response to the therapeutic interaction with the practitioner.
It is also critical to realize that placebo responses vary greatly depending on the disease or symptom that is being treated and the outcome that is being measured. Placebo response is greatest for subjective symptoms of conditions that are known to be modified by things like mood and attention, while it is virtually non-existent for objective outcomes in pathological conditions. So there is a substantial placebo response for pain and nausea, but nothing significant for cancer survival.
I don’t know how I’ve missed this, given that it’s been in existence now for a month and a half, but I have. Regular readers (and even fairly recent readers, given that I write about this topic relatively frequently) know that I’m not a big fan of the National Center for Complementary and Alternative Medicine (NCCAM). (Come to think of it, neither is anyone else writing for this blog.) Just search this blog for “NCCAM” if you don’t believe me. I’ve explained the reasons many times, but the CliffsNotes version is that NCCAM is an enormous waste of taxpayer money, dedicated as it is to the study of modalities that are at best highly implausible and at worst break well-established laws of physics (i.e., “energy healing”). I do concede that, since the latest NCCAM director (Dr. Josephine Briggs) took over, there has been a noticeable attempt to bring more scientific rigor to NCCAM, and to some extent Dr. Briggs has succeeded. At the very least she is a legitimate scientist with an impressive pre-NCCAM track record, and I do fear who will succeed her when she moves on or retires given that there is enormous pressure from the CAM community to appoint one of their own as director.
Unfortunately, as rigorous a scientist as Dr. Briggs was in her former life, since coming to NCCAM she has gradually been assimilated into the culture of the place. Indeed, although it is good that NCCAM has backed away from studying woo like homeopathy and distance healing, the co-optation of science-based modalities such as exercise, diet, and natural products pharmacology has continued apace. Worse, the recently released five year strategic plan for NCCAM admitted that the science funded by NCCAM in the past was crap and, in essence, promised to do some real science for a change. That’s why on occasion I’ve jokingly said that we should take off and nuke NCCAM from orbit. It’s the only way to be sure. On the other hand, no doubt someone would think I seriously mean that we should nuke NCCAM. Of course, I’d never advocate that! NCCAM is located right smack dab in the middle of the NIH campus. The collateral damage would be unacceptable.
I keed. I keed. I’m not kidding, though, when I echo the questioning of why NCCAM still exists.
A few months ago I wrote about Fabrizio Benedetti’s research on the neurobiology of the placebo response, and a discussion about placebos and ethics ensued in the comments. Now Dr. Benedetti has written about that issue in a “Perspective” article in the journal World Psychiatry, “The placebo response: science versus ethics and the vulnerability of the patient.”
We have learned that verbal suggestions can activate neurotransmitters and modulate pain perceptions, and positive expectations can activate endogenous opioid and cannabinoid systems. A complex mental activity has objective effects on body physiology. Words and drugs can activate the same mechanisms. Drugs are less effective without therapeutic rituals. We are delving deep into human foibles and vulnerable traits at the center of human interactions. What implications do these insights into mind-body interactions have for patient care?
A Loose End
In the last post I wondered if Ted Kaptchuk, when he wrote the article titled “Effect of interpretive bias on clinical research,” had understood this implication of Bayes’s Theorem: that interpretations of most scientific investigations are exercises in inverse probability, and thus cannot logically be done without consideration of knowledge external to the investigation in question. I argued that if Kaptchuk had
…understood the point when he wrote his treatise, he was dishonest in not explaining it and in not citing at least one pertinent article, such as Steven Goodman’s (which I’m willing to bet he had read). If he didn’t understand the point he should have withheld his paper.
In researching more of Kaptchuk’s opinions I’ve discovered that he had certainly read Goodman’s article, but that he either didn’t understand it or preferred to obscure its implications in deference to his ongoing project in belittling scientific knowledge. In a letter to the editor of the Annals of Internal Medicine in 2001, Kaptchuk opined that even if “more trials of distant healing with increased methodologic rigor” were positive, it still would not “be persuasive for the medical community”:
The situation resembles the predicament with homeopathy trials, another seemingly implausible intervention, where the evidence of multiple positive randomized, controlled trials will not convince the medical community of its validity. Additional positive trials of distant healing are only likely to further expose the fact that the underpinning of modern medicine is an unstable balance between British empiricism (in the tradition of Hume) and continental rationalism (in the tradition of Kant).
…It seems that the decision concerning acceptance of evidence (either in medicine or religion) ultimately reflects the beliefs of the person that exist before all arguments and observation. [Kaptchuk cites the second of the two Goodman articles that I referred to above, discussed here]
“Strong Medicine”: Ted Kaptchuk and the Powerful Placebo
At the beginning of the first edition of The Web that has no Weaver, published in 1983, author Ted Kaptchuk portended his eventual academic interest in the placebo:
A story is told in China about a peasant who had worked as a maintenance man in a newly established Western missionary hospital. When he retired to his remote home village, he took with him some hypodermic needles and lots of antibiotics. He put up a shingle, and whenever someone came to him with a fever, he injected the patient with the wonder drugs. A remarkable percentage of these people got well, despite the fact that this practitioner of Western medicine knew next to nothing about what he was doing. In the West today, much of what passes for Chinese medicine is not very different from the so-called Western medicine practiced by this Chinese peasant. Out of a complex medical system, only the bare essentials of acupuncture technique have reached the West. Patients often get well from such treatment because acupuncture, like Western antibiotics, is strong medicine.
Other than to wonder if Kaptchuk had watched too many cowboy ‘n’ Native American movies as a kid, when I first read that passage I barely blinked. Although the Chinese peasant may have occasionally treated someone infected with a bacterium susceptible to his antibiotic, most people will get well no matter what you do, because most illnesses are self-limited. Most people feel better even sooner if they think that someone with special expertise is taking care of them. If you want to call those phenomena the “placebo effect,” in the colloquial sense of the term, fine. That, I supposed, was what Kaptchuk meant by “strong medicine.”
Turns out I was mistaken. Let’s briefly follow Kaptchuk’s career path after 1983. In the 2000 edition of The Web, he wrote:
There has been an ongoing debate about placebos on SBM, both in the articles and in the comments. What does it mean that a treatment has been shown to be “no better than placebo?” If our goal is for patients to feel better and they feel better with placebos, why not prescribe them? Do placebos actually do anything useful? What can science tell us about why a patient might report diminished pain after taking an inert sugar pill? The subject is complex and prone to misconceptions. A recent podcast interview offers a breakthrough in understanding.
On her Brain Science Podcast Dr. Ginger Campbell interviewed Dr. Fabrizio Benedetti, a physician and clinical neurophysiologist who is one of the world’s leading researchers on the neurobiology of placebos. A transcript of the interview [PDF] is available on her website for those who prefer reading to listening. The information Dr. Benedetti presents and the expanded remarks by Dr. Campbell after the interview go a long way towards explaining the placebo phenomenon and its consequences for clinical medicine. Dr. Campbell also includes a handy list of references. I’ll try to provide a summary of the main points, but I recommend reading or listening to the original.
A common misconception is that the response to placebos is a purely subjective psychological response involving only the cortical level of the brain; but evidence is accumulating that real, measurable, objective subcortical neurophysiologic phenomena are involved. One of the first hints was a 1978 study showing that the placebo response to pain could be blocked by naloxone, a narcotic antagonist drug, indicating that the placebo must have actually caused an increase in endogenous opioids. (more…)