Placebo has its effect through our beliefs and expectations. Because we get many of our assumptions through culture, changing social attitudes could alter how effective it is.
Placebo is sometimes called the ‘expectancy effect’ and describes the fact that our expectations of what the dummy treatment will do can influence the outcome.
We noted before that the colour of the pill can significantly alter its effect, but it’s intriguing to think that we probably get most of these sorts of expectations from our culture.
Bad Science looks at how the strength of the placebo effect has changed over time for different drug trials, suggesting that as our cultural beliefs change, the effectiveness dummy treatments might also change depending on how they’re presented.
Similarly, The New York Times have just published a brief article on a new study that found placebos described as costing $2.50 a dose are more effective pain killers than those presented to participants as costing 10 cents a dose.
In other words, if placebo is a form of faith healing, changes in our collective faith will alter the healing potential of a placebo associated with those ideas.
These social effects on placebo are interesting, because we judge the effectiveness of medications by comparing them to placebo. Furthermore, we know the effectiveness of most medications will be partly explained by the placebo effect.
In other words, changes in our cultural attitudes influence the effectiveness of medication.
While we assume that much of medicine objectively definable, much is only comprehensible by making sense of social issues.
For example, drug side-effects are usually talked about as if they are objectively described properties of the chemical.
However, its easy to see that these actually depend on the person, not the drug.
For example, take the drug terazosin. It lowers blood pressure and shrinks the prostate.
If you have high blood pressure but a normal prostate, the side-effect is a reduced prostate. If you have prostate problems but normal blood pressure, the side-effect is reduced blood pressure. If you have both high blood pressure and prostate problems, it’s potentially side-effect free.
One man’s treatment is another man’s side-effect. This is why the sociology of medicine is as important as biology, chemistry or another other bench-based science in understanding illness and treatment.
Link to Bad Science on placebo.
Link to NYT on price of placebo study.