For myself, this makes a difference in several ways. First, the work that goes into designing a study (before the first patient is ever recruited) provides some measure of assurance that contraindications and circumstances elevating risk factors and characteristics of patients likely to benefit have been given some serious thought. Second, the oversight provided in a well designed study (a broad range of markers being assessed and a review committee looking for early signs of trouble or patterns that emerge from within a treatment group and their power to stop the study early if warranted) provides an added level of review. Third, in the worst case scenario (some catastrophic reaction), the risk/benefit ratio has still been shifted in favor of a benefit to society if not for myself.
I would hope that whatever went wrong would be studied. If the same thing were to happen independent of a well designed study, I'm quite sure that my personal problems would be used to condemn the entire endeavor. That would simply compound the loss. ME is far too loosely defined to generalize from one person's lack of response to a treatment (or severe adverse reaction) onto the entire ME/CFS community. I would want there to be some sort of postmortem (literally or figuratively) in order to learn whether or not it is reasonable to generalize from my bad experience (I'm not naive enough to think that someone somewhere would not try to politicize any negative response to treatment - and many people have no clue about the real dangers of doing nothing!). Again, this may not change the negative impact the treatment had on me personally but the thought that something important could be learned about ME would shift my risk/benefit calculation further towards the benefit side.
