October 23, 2015


Why are placebos getting more effective? (William Kremer, 10/20/15, BBC World Service)

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. [...]

Drug companies were probably hoping that larger, more ambitious trials would be better at showing the real effect of drugs, Mogil thinks, but in fact the big budgets may have made things worse, he suggests.

A well-funded trial would be reflected in lots of small ways that might come together to increase patients' confidence that they were engaged in a clinically beneficial process. Just adding a snazzy logo to a research trial could make people feel more optimistic.

Mogil believes that US companies are more likely than others to use contract research organisations (CROs) to conduct trials (though since the companies don't have to declare this, it is hard to know for sure). It may be that the staff who work at these service organisations are friendlier than the busy researchers who conduct academic trials. That in itself could make people feel better.

Posted by at October 23, 2015 11:59 AM

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