Placebos are in the news again. This time in conjunction with homeopathy of all things. Doctors in the United Kingdom's National Health Service (NHS) voted on whether homeopathy should be provided and paid for by the NHS. There were doctors who thought it should be provided. They didn't think homeopathy was proven by evidence based medicine but because it did provide some relief as a placebo. The vote went against homeopathy but the question of how doctors should handle placebo effects was left unresolved. Martin Robbins summarizes the issue well in the Guardian.
Placebos are simple. Have a doctor give a sugar pill or a saline solution to a patient while saying it's an effective medicine. If the patient believes it is a real medicine they end up thinking that it works. Simple right?
Turns out it isn't that simple. In some cases placebos can actually generate an internal chemical response in patients. Give people a placebo painkiller and they will secret opiods that are pain killers. So it isn't all in the mind.
It gets even weirder. Expensive placebos work better than ones that cost less. We apparently adjust our internal expectations to match our value judgements.
Dan Ariely talks about his research in a talk at Cody's Books that was captured by fora.tv. The section on placebos in particular is excerpted here. The talk covers a wide range of topics that he's explored so expect to be drawn in to the full talk. You'll end up learning a great deal about things other than placebos.
Even weirder the power of placebos isn't just tied to how much they cost. It's tied to what we think modern medicine can do for us. Studies have shown that placebos work as well as antidepressants. But not because antidepressants don't work. They work very well. We 'allow' placebos to work because we think they are the medicine they are replacing. If you tried to give me a placebo for something I don't think medicine can cure then the placebo may not be that effective. But give me a placebo to help me with something I know is treatable and the results are different.
Jay Dixit's 2002 article New! Improved! And Still 100 Percent Fake is a great overview of the increasing power of placebos.
Both Dan Ariely's talk and Jay Dixit's article raise interesting issues. What would happen if medical studies told us how much the drug might cost? How can we take all the research into placebos and the way in which our perceptions help our treatments and turn that information into better ways of delivering care? Can we use the power of our minds that placebos uncover in conjunction with real medical treatments?
It begs the question... how can we fool ourselves into being healthier? And will it work if we know we're doing it to ourselves?