As you know, I am a big proponent of placebos when used in
the appropriate places. They can have pretty strong effects, have fewer side
effects, and can cost a lot less. For
example, there is a lot of evidence that placebos work about as well as most of
the anti-depressants on the market today.
Similar results have been found for over-the-counter pain relievers and
cold medicines.
The one major hesitation I have for placebos is the ethics
behind it. In my behavioral design work, I often stress that it is important
that any nudges to the choice architecture need to be transparent. Users need to know that their behavior is
being influenced, why that influence supports their own personal goals and best
interests, and give them the autonomy to refuse if they want.
How can we do that with placebos? Won’t placebos crash and burn if we have to
tell users ahead of time that they are taking one? There are some people with
enough top-down mental control that they can use placebos even when they know,
but this is not a common trait.
It turns out, there is a way.
A recent study by the Cognitive and Affective
Neuroscience Lab at Colorado University – Boulder found one.
What they did was apply a hot ceramic plate
to the user’s arm (not enough to really burn them –we have ethics after all)
and then give them a supposedly analgesic gel that was really a placebo. They
secretly turned down the temperature of the ceramic plate so the user thought
that it was the gel that was making their arm feel cooler.
After doing this four times, the users “learned” that the
gel cooled down their arms. Once this
learning had occurred, the experimenters revealed that the gel was only a
placebo. And it would still work. After
just one or two repetitions, it would not.
This makes scientific sense.
We have talked before about how hard it is to “unlearn” something.
There is a neuropsychological process to
create a new memory or to strengthen an existing memory.
But there is not one to erase a memory.
There is
reconsolidation to modify one, but that is not the same thing.
So if the link between the gel and the cooling (or the link from any
placebo to its effects) is learned strongly enough (four repetitions in this
case), the knowledge that it is a placebo doesn't “unlearn” the link that has
been created in your brain.
It seems to me that this is a nice middle ground that
balances the effectiveness of the placebo and the need to be transparent when
prescribing one. Give the patient a
chance to learn the placebo effect, then tell them it is a placebo, and then
give them the autonomy to choose.
Last minute
update:
There is a great term for how susceptible we are to the
placebo effect – the placebome. It is a riff on the trend to name every
biological attribute as an “-ome” of some sort. Genome was the real one. Then we got the biome and microbiome and . .
.
But seriously, it turns out that there are a few genes that
predispose us to be more or less susceptible to the placebo effect.
So says researchers at the Beth Israel
Deaconess Medical Center.
