Placebo response growing over time - but only in America
A new study finds that rising placebo responses may play a part in the increasingly high failure rate for clinical trials of drugs, but the authors of the study say that the increase in placebo responses occurred only in trials conducted in the United States.
From 1990 to 2013 the pain inhibition experienced by patients in the placebo group increased steadily, reaching an average 30 percent decrease in pain levels by 2013. Similar increases in placebo response have previously been observed in studies of clinical trials of antidepressants and antipsychotic drugs. Those studies, however, didn't pinpoint the U.S. as the source of the trend.
The authors, from McGill University, examined reported features of the clinical trials to determine what factors might be responsible for the changes over time. They found that in the U.S., but not elsewhere, trials are becoming longer (from an average of four-weeks long in 1990 to 12 weeks in 2013) and larger (from an average of fewer than 50 patients in 1990 to an average of more than 700 patients in 2013).
"The data suggest that longer and larger trials are associated with bigger placebo responses," said Jeffrey Mogil, senior author of the new paper. "This, in turn, tends to result in the failure of those trials - since it makes it harder for pharmaceutical companies to prove that the drug being tested is more effective than treatment with a placebo." He and his co-authors note, however, some potentially important differences between the U.S. and other countries. These include the existence of direct-to-consumer drug advertising in the U.S. (New Zealand is the only other country in the world that allows this), the greater spread of for-profit "contract research organizations" in the U.S., and perhaps greater exposure to the placebo concept in popular media in the U.S.
http://www.scienceagogo.com/news/20150906175924.shtml
From 1990 to 2013 the pain inhibition experienced by patients in the placebo group increased steadily, reaching an average 30 percent decrease in pain levels by 2013. Similar increases in placebo response have previously been observed in studies of clinical trials of antidepressants and antipsychotic drugs. Those studies, however, didn't pinpoint the U.S. as the source of the trend.
The authors, from McGill University, examined reported features of the clinical trials to determine what factors might be responsible for the changes over time. They found that in the U.S., but not elsewhere, trials are becoming longer (from an average of four-weeks long in 1990 to 12 weeks in 2013) and larger (from an average of fewer than 50 patients in 1990 to an average of more than 700 patients in 2013).
"The data suggest that longer and larger trials are associated with bigger placebo responses," said Jeffrey Mogil, senior author of the new paper. "This, in turn, tends to result in the failure of those trials - since it makes it harder for pharmaceutical companies to prove that the drug being tested is more effective than treatment with a placebo." He and his co-authors note, however, some potentially important differences between the U.S. and other countries. These include the existence of direct-to-consumer drug advertising in the U.S. (New Zealand is the only other country in the world that allows this), the greater spread of for-profit "contract research organizations" in the U.S., and perhaps greater exposure to the placebo concept in popular media in the U.S.
http://www.scienceagogo.com/news/20150906175924.shtml
A third option is that this study may simply be wrong: "I don't think that controlling the placebo response will increase the number of successful trials. What drug companies have to do is to find more effective drugs." -Fabrizio Benedetti, who studies placebo responses at the University of Turin, Italy.
http://www.nature.com/news/strong-placebo-response-thwarts-painkiller-trials-1.18511"more than 90% of potential drugs for treatment of neuropathic and cancer pain have failed at advanced phases of clinical trials"While new drugs get new patents, the old drugs remain just as cheap. If you don't have a good reason to use the newer one... don't!
But new drugs are still important. Some people have bad reactions to components of certain drugs, but do fine with others. Different drugs have different side effects. The effectiveness of new drug may be significantly better than the existing drug on specific stages of illness (e.g. diagnosis too late-stage for the cheaper medication to be effective). Of all the problems that exist in pharmaceuticals, too-many good & effective drugs isn't one of significant concern.