Sunday, November 15, 2015

Taste the placebo

One of my students asked me if I make the memes that I use in this blog: the answer is "no" - truly, I am too busy grading papers. Fortunately there are a lot of memes floating around social media. Most of the time I start with a meme and then do a literature search to find recent research on that topic. Other times, like this week, I find a great article then search Google Images for a meme to match. Sometimes I stumble upon the perfect combination and reach article/meme perfection:


Would it be mean to trick a hurting person into thinking that a piece of candy is actually a tablet of pain reliever? The answer would be, "yes" if the act of swallowing that orange Skittle would have no effect on her headache - but what if it helped just as much as a real Advil?

Faasse, Martin, Grey, Gamble, and Petrie (2015) conducted a simple experiment to answer a similar question. They recruited 87 New Zealander university students (83% female) who frequently suffered from headaches. The students were each given four identical-looking tablets: two were labeled "Nurofen," a brand name for Ibuprofen - like Advil in the United States, and the other two were labeled "Generic Ibuprofen." Thus, each of them believed that he or she received two brand name pills and two generic pain-relief pills.

However, the researchers had tricked them with some mild deception! For each participant one of the tablets labeled "Nurofen" was actually a placebo (a sugar pill) containing no medicine - much like a Skittle; likewise, one of the tablets labeled "Generic Ibuprofen" was also a placebo. The remaining two tablets were always identical doses (400 mg) of Ibuprofen; there was no difference beyond how they were labeled. This was a within-subjects experiment because all participants experienced all of the possible versions of the tablet: placebo labeled Nurofen; Ibuprofen labeled Nurofen; placebo labeled Generic; Ibuprofen labeled Generic.

The participants were instructed to use the tablets for their next four headaches, and the order of the pills was dictated by the researchers for counter-balancing. Each time the participants got headaches they had to rate the intensity of their pain, take the designated tablet, wait one hour, and then rate the intensity of any remaining pain and note any side effects.

As you would expect, the overall results showed that Ibuprofen did a better job than the placebo at resolving headache pain. What was more interesting to Faasse et al. was that placebo and Ibuprofen tablets labeled Nurofen were rated equally well on pain relief. In this case, the Placebo Effect was clear: just believing that you took brand name Ibuprofen was enough to cure your pain as well as the real medicine would!

Alternatively, when participants took the tablets labeled "Generic Ibuprofen," pain relief was much higher from the actual Ibuprofen than from the placebo. Again participants' beliefs influenced their experiences: in this case a mistrust of off-brand medicines overcame the Placebo Effect.

Side effect data followed a similar trend: when participants believed that they were taking "Generic Ibuprofen" they reported more side effects from the placebo tablets than from the actual Ibuprofen (that really could produce side effects)! When placebos produce negative effects this is call the Nocebo Effect. This Nocebo Effect was limited to the Generic labeled tablets. No difference in side effects was seen between the placebo and Ibuprofen when they were labeled Nurofen, so a mistrust of off-brand medicine encouraged the Nocebo Effect.

Faasse et al.'s experiment would suggest that orange Skittles stored an old Advil bottle would probably fix your sister's headache just as well as actual medicine! On the other hand, if she saw the Skittles come out of a store brand (generic) bottle she might be complaining an hour later: her head would still hurt and the "pills" you gave her are upsetting her stomach. Of course, the side effects of tricking your sister would be far worse than a headache, so please don't try this at home.

Further Reading:

The Faasse et al. (2015) article is available online or can be obtained through your local college library.

Curious about the placebo effect in medicine? Get two perspectives from an article in the New England Journal of Medicine by Drs. Ted Kaptchuk and Franklin Miller, and from a TED talk by Dr. Lissa Rankin.

Orange Skittles resemble Advil: similarities between candy and medicine can lead to accidental poisoning of children. Play the Pill vs Candy game from California Poison Control. Can you tell the difference between a sweet treat and a pharmaceutical?

BONUS:

Our suspicion of generic brands extends to other products as well. Watch some of the Buzzfeed crew attempt to tell the difference between off-brand and brand name cereals.


No comments:

Post a Comment