Dummy pills or ‘placebos’ that contain no medicine may give some relief to people with migraine - even when people know that they are taking a placebo.
BMJ Group News
What do we know already?
We know that the so-called ‘placebo effect’ can cause surprisingly big improvements in symptoms across a range of illnesses. A placebo is a medicine or treatment that has no active ingredient and that shouldn’t give any benefit. But it often does. This is probably because people have a tendency to feel better when they take a treatment, because they expect to feel better.
This is why in studies, new medicines are tested against placebos. So if a drug company invents a new headache pill, it will be tested by giving one group of people the real drug and another group a placebo. The people won’t know which they’re taking. If, when the results are measured and compared, the real drug doesn’t perform a good deal better than the placebo, it has failed the test.
So the placebo effect is really useful for research. But could understanding more about it help lead to better ways of treating people?
To find out more, researchers in the US designed a study into how placebos might affect migraine headaches. They were pretty sure that placebos would have some effect on pain if people didn’t know that they were placebos. So they went further and looked at whether the effect of both placebos and medicines might change depending on what people were told they were taking.
The researchers recruited 66 people who regularly suffered with migraines. They gave them each six envelopes. Each contained a pill - one to take for each of their next six migraines. Three of each person’s envelopes contained the migraine medicine rizatripan, and the other three contained a placebo pill. Now here’s where it gets complicated.
The three envelopes containing rizatripan pills were labelled differently: one was labelled as rizatripan, another as placebo, and the third as rizatripan or placebo - so that the patient didn’t know which it was. The same applied to the envelopes with the placebos. One was labelled as placebo, one as rizatripan, and the last as rizatripan or placebo. So when people had a migraine they thought they knew what they were taking - even if it was only a placebo. Except that some of the time they were being given false information.
In general, rizatripan was better than placebo at relieving pain. But it wasn’t that simple. For example:
the painkilling effect of the placebo pills was highest when people thought they were taking a real drug, compared to when they thought they might be taking a placebo
the painkilling effect of the real drug was highest when people thought they were taking a real drug, compared to when they thought they might be taking a placebo
the placebo labelled as the real drug was just as effective as the real drug labelled as a placebo
placebos worked better than taking nothing at all
the placebo had some effect on pain even when people knew they were taking a placebo.
The researchers found this last result the most surprising. To explain it, they think that the very ritual or routine of taking a pill - even one that they knew was useless - worked in a small way to make people think that they were being helped. Across all the results, how much people’s symptoms improved depended not just on what they took, but on what they were told about what they took.
To provide even greater transparency and choice, we are working on a number of other cookie-related enhancements. More information