I think a lot of people see the placebo effect as a trick for the gullible. Maybe, some folks think, if the placebo effect works on you, you weren't actually sick or in pain to begin with - you just thought you were.
But actually, the placebo effect can impact anyone - regardless of their intelligence or general level of gullibility. Placebos work on about a third of the people who try them, give or take. And in recent years, scientists have found that the placebo effect doesn't just effect a patient's perception of their own symptoms.
A couple of years back, Harvard opened a Placebo Studies institute, which I like to believe is a school where half of students aren't actually learning anything, about one third of whom will think they actually did learn something. Anyway, the institute has made some startling discoveries. When they gave Parkinson's patients a placebo injection, not only did the patients feel better, they actually produced more of the dopamine that the disease destroys. Placebos change brain chemistry. They change vital signs.
They even work when patients know they're getting them. A few years back, researchers gave IBS sufferers a placebo - and told them they were getting a placebo. Despite this, patients on the placebo showed greater improvement, both in objective and subjective assessments than did patients who took nothing at all.
Of course, placebos work better when a patient doesn't know they're getting placebo. The more a person believes the placebo will work, the more likely it is to do so. And the type of placebo matters too.
Red placebos make patients feel jittery. Blue placebos make them sleepy. Capsules are better than tablets. Two pills are better than one. Placebos disguised as brand name products work better than generic placebos. Placebos work better the more the subject thinks they cost. Placebos even work better if the person who provides them is wearing a lab coat.
In general, less pleasant placebos fare better. Injections work better than pills, electric stimulation better than injections, sham surgery (which is horrifyingly a thing) works best of all. Placebos that have unpleasant side-effects (or those that come with a warning of unpleasant side effects) work better as well.
All of this raises some interesting ethical questions. Would it be ethical for a doctor to prescribe a placebo if a proper medical treatment wasn't available? Are homeopathy and other complete shams okay if they can make people feel better? (No. More on that in a future post). If a placebo has real medicinal value, can it really be called a placebo?