Throughout the year in SC 200, we have discussed double blind placebo trials and many other types of trials that require placebo groups. Double blind Placebo trials are especially important in clinical trials, testing the effectiveness of drugs. It is necessary to have a placebo/control group so that there is something to compare the experimental group to. However, sometimes the placebo group elicits a response because people think that they are getting the medicine so they report feeling better. Having said this, in recent years, there has been a large increase in placebo responses in clinical trials. The curious thing about this observation is that the increase in placebo responses have only been observed in the United States.
In one meta analysis, a study published in the journal Pain from McGill University, the researchers observed 83 trials investigating the effectiveness of pain medication. These studies span many years from 1990 to 2013. The researchers found that the reported levels of pain decreased steadily over the years reaching an average of 30% decrease in 2013. Similarly, many other clinical trials were investigated which had to do with antidepressant drugs and anti psychotic drugs and a similar trend was observed. This meta analysis compared the results of these trials in multiple countries and found that there has only been an increase in placebo response in US trials. Also Fabrizio Benedetti, who studies placebo responses at the University of Turin, observed the same increase in placebo responses in the US. But, why is this happening.
There are no definite answers to this questions, but scientists believe the evolving nature of clinical trials in America is playing a role in the trend. In America, trials on average are becoming longer and are involving more people. For whatever reason, it is believed that trials that take place over a longer period of time and have more participants elicit a larger placebo response.
Another reason why placebo responses may be increasing in America is that the United States is one of only two countries (New Zealand) that allow for drug companies to create advertisements promoting their drug. This fact means that Americans are more likely to believe that drugs will work than other people around the world who are not constantly exposed to these advertisements. If Placebo responses are increasing, what effect does this have on clinical trials.
An increased placebo response directly leads to an increase in the failure of clinical trials. This is because if a drug decreases a person’s pain by 40%, but people in the placebo group are reporting a 30% decrease in pain, there may not be a large enough difference between the two groups to conclude that the drug works. This is a massive issue because if we can not prove that drugs work through double blind control trials then how can we prove that they are effective? Moreover, there are no easy solutions to this issue.
One possible solution is to end the advertisement of drugs. However, this would create a huge legal struggle with the drug companies who runs the advertisements. Another possible solution might be to decrease the size of the trials. But, we know that increasing the size of a trial makes the trial more accurate so we would be sacrificing accuracy in order to decrease the placebo response. The last possible solution is to decrease the length of the trials. This is a possible solution but the link between longer trials and increased placebo response is extremely murky.
Having said this, I believe that the true cause of increased placebo responses in America is rooted in the increase of advertisements through television and the internet. In my opinion, this is the only logical connection. There is no reason that the increased size or length of a trial should increase the placebo effect. But, the overwhelming affect of television, internet, and social media in American’s lives forces us to pay attention to advertisements. One possible experiment to prove this is to create four groups in a double blind control trial. Expose one group to a series of drug adds then the placebo, expose one group to no drug adds then the placebo, expose on group to drug adds and the actual drug, and expose one group to drug adds then the placebo and compare the results. A possible issue with this is that the trial would not be fully double blind because the people would know if they were watching a drug add or not. However, I believe that the trial would still yield useful data.
Work Cited:
http://www.nature.com/news/strong-placebo-response-thwarts-painkiller-trials-1.18511
https://www.mcgill.ca/newsroom/channels/news/american-placebo-255973