As scientists, the placebo effect is something we learn about early on, even those of us that don’t do clinical research. Today I had the opportunity to attend a seminar discussing placebos in the context of clinical trials, presented by Mark W. Green, MD of Columbia University. Green offered a full review of placebo research, covering virtually all of the last century. However, amidst the placebo discussion, he mentioned something that I had never heard of before, the nocebo. According to the Medline Plus medical dictionary, a nocebo is a harmless substance that when taken by a patient is associated with harmful effects due to negative expectations or the psychological condition of the patient. It is sort of the antimatter of the placebo effect. If you condition someone to believe a treatment will have an adverse effect, it is likely the patient or subject will have an adverse response, independent of treatment.
In reading about the nocebo effect, I came across an article that suggests certain phrases commonly used in medical practice can generate negative feelings in a patient, conditioning them to a negative response. According to the article, words such as just and normally tend to elicit negative and somewhat paradoxical responses from the patient.
Just breathe normally.
I am breathing heavy just reading that.
Though this discussion may not have direct implications for us as bench scientists, Green’s presentation and my subsequent reading made me aware of the ultimate uncontrolled variable in clinical research, the subject. Thus, no matter how we control a study, single-, double- or triple-blind, the psychological effects of treatment, both placebo and nocebo, will always play into your findings.
Today I am thankful that yeast1 don’t have a brain.
1 The model system we use in my lab.
Hi Caryn,
Was reading about the very same thing this morning in a recent NewScientist piece. Included a story of a guy who, after his girlfriend dumped him, scoffed the bottle of anti-depressants he was taking as part of a clinical trial. Then regretted it, got worried, and was taken to hospital, apparently very ill. The only thing that sorted him out was being informed he was in the control group. (But I wonder whether he actually was, and whether they duped him, placebo-like?)
And what if the girlfriend was part of the study as well? They may have recruited the volunteers for a regular study, then screened them for relationship status, then secretly contacted their girlfriends to get them to dump them in exchange for a hefty sum, causing them to voluntarily overdose on nocebos! It’s hard to think of an ethical control group for that, though…
Written and directed by Oliver Stone.
Caryn, thats an interesting factoid for the day—the ‘nocebo’.
So long as your expectation of a negative/positive outcome of your experiments with yeast doesnt actually affect the results, you are safe :)
And Cristian, I’m not sure if that would be a funny or a scary movie!
Lee- What timing! You couldn’t have found a better story to spark discussion of nocebo. Thanks!
Cristian- Are you gong to pitch that film? Haha…
Ranjani- Even if my expectation does affect my results, I am an optimist, so it should help!
My GP in Australia told me once that in days gone by it was common for them to prescribe a placebo (literally a sugar pill or similar) if they thought the patient wasn’t actually ill. He also lamented the fact that it had been discouraged or even outlawed.
Is that person still your doctor?
Unfortunately not, he was awesome. He retired recently, then sadly passed away a few days later :( Had been my doctor since I was a baby, truly from the old-school of committed family GP’s. Have been trying to find a decent replacement ever since.