American placebo – An increase in the placebo response, 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 designed to control chronic pain caused by nerve damage. Surprisingly, however, the analysis of clinical trials conducted since 1990 found that the increase in placebo responses occurred only in trials conducted wholly in the U.S.; trials conducted in Europe or Asia showed no changes in placebo responses over that period.
