It's important to understand that if a clinical trial shows some improvement in the control group that received placebo, this does not need to be due to some pl

It's important to understand that if a clinical trial shows some improvement in the control group that received placebo, this does not need to be due to some placebo 'effect' at all. The status of patients usually changes all the time. If the control group had some minor improvement in some endpoint, this might be due to wide variety of reasons. For example, the disease might just get somewhat better by itself. This does not necessarily imply that this was due to patients that were given placebo experiencing a placebo effect. They might just as well have gotten better without the placebo.