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When new drugs are put on the market, clinical trials determine whether they perform better than inactive pills known as "placebos". Research shows that over the last 25 years the difference in effectiveness between real drugs and these fake ones has narrowed - but more in the US than elsewhere. Are Americans really more susceptible to placebo effects, or is something else going on?
If you were a sick Londoner in the late 18th Century several treatment options were open to you. By no means the cheapest of these was to go along to a little shop on Leicester Square, hand over five guineas and receive a pair of pointy metal rods that would suck the disease from your body.
These instruments were called Perkins Tractors, after their American inventor Elisha Perkins, who claimed George Washington as a customer. They worked, it was said, because they were made of special alloys.
But in 1799 the renowned physician John Haygarth decided to test whether they really worked, and at the same time perform a scientific examination of "that faculty of the mind, that is denominated the Imagination". He organised a trial at a hospital in which five people suffering chronic rheumatism were treated with replica wooden tractors.
"All five patients, except one, assured us that their pain was relieved," he reported. "One felt his knee warmer, and he could walk much better, as he shewed us with great satisfaction. One was easier for nine hours, and till he went to bed, when the pain returned. One had a tingling sensation for two hours."
When the "real" metal tractors were used on the second day, they had much the same effect as the fake ones. "Such is the wonderful force of the Imagination!" mused Haygarth.
The phenomenon of patients feeling better simply because they believe a treatment will help them has come to be known as the placebo effect (find out why at the bottom of the page). It comes into play most often when people are experiencing pain, fatigue, depression and nausea. Scans of patients taking a placebo show their brains switching on parts that can help control stress and pain.
When new drugs are being trialled in the US, the Food and Drug Administration (FDA) demands that the researchers factor in the placebo effect. They do this by engaging in controlled trials in which some participants are given the real drug and some are given a placebo - participants are generally not told whether their treatment contains the drug being tested or not.
The drug's effectiveness is then determined by subtracting the placebo response - the extent to which patients in the placebo group get better - from the drug response. Before allowing a drug to go on the market, the FDA demands that it has been shown to outperform a placebo by a significant margin.
It seems, though, that this is happening less and less, because the placebo response has been steadily strengthening. Tests reveal that some well-known drugs for depression and anxiety would struggle to pass their clinical trials if they were re-tested in 2015.
This trend has become a huge concern for the pharmaceutical industry. A slew of drugs have flopped at these final clinical trials, by which time drugs companies have typically spent more than $1bn in research and development.
No-one knows why the placebo response is rising but a fascinating new study in the journal Pain might help experts pin it down.
Drawing on data from 80 trials for drugs to treat neuropathic pain, the researchers led by Dr Jeffrey Mogil at McGill University in Montreal found that the trend was being driven by studies conducted in the US. Americans seem to be getting better merely by taking part in studies these days, regardless of whether they have been given real drugs or not.
Full Story: Why are placebos getting more effective? - BBC News
If you were a sick Londoner in the late 18th Century several treatment options were open to you. By no means the cheapest of these was to go along to a little shop on Leicester Square, hand over five guineas and receive a pair of pointy metal rods that would suck the disease from your body.
These instruments were called Perkins Tractors, after their American inventor Elisha Perkins, who claimed George Washington as a customer. They worked, it was said, because they were made of special alloys.
But in 1799 the renowned physician John Haygarth decided to test whether they really worked, and at the same time perform a scientific examination of "that faculty of the mind, that is denominated the Imagination". He organised a trial at a hospital in which five people suffering chronic rheumatism were treated with replica wooden tractors.
"All five patients, except one, assured us that their pain was relieved," he reported. "One felt his knee warmer, and he could walk much better, as he shewed us with great satisfaction. One was easier for nine hours, and till he went to bed, when the pain returned. One had a tingling sensation for two hours."
When the "real" metal tractors were used on the second day, they had much the same effect as the fake ones. "Such is the wonderful force of the Imagination!" mused Haygarth.
The phenomenon of patients feeling better simply because they believe a treatment will help them has come to be known as the placebo effect (find out why at the bottom of the page). It comes into play most often when people are experiencing pain, fatigue, depression and nausea. Scans of patients taking a placebo show their brains switching on parts that can help control stress and pain.
When new drugs are being trialled in the US, the Food and Drug Administration (FDA) demands that the researchers factor in the placebo effect. They do this by engaging in controlled trials in which some participants are given the real drug and some are given a placebo - participants are generally not told whether their treatment contains the drug being tested or not.
The drug's effectiveness is then determined by subtracting the placebo response - the extent to which patients in the placebo group get better - from the drug response. Before allowing a drug to go on the market, the FDA demands that it has been shown to outperform a placebo by a significant margin.
It seems, though, that this is happening less and less, because the placebo response has been steadily strengthening. Tests reveal that some well-known drugs for depression and anxiety would struggle to pass their clinical trials if they were re-tested in 2015.
This trend has become a huge concern for the pharmaceutical industry. A slew of drugs have flopped at these final clinical trials, by which time drugs companies have typically spent more than $1bn in research and development.
No-one knows why the placebo response is rising but a fascinating new study in the journal Pain might help experts pin it down.
Drawing on data from 80 trials for drugs to treat neuropathic pain, the researchers led by Dr Jeffrey Mogil at McGill University in Montreal found that the trend was being driven by studies conducted in the US. Americans seem to be getting better merely by taking part in studies these days, regardless of whether they have been given real drugs or not.
Full Story: Why are placebos getting more effective? - BBC News