Should the FDA prohibit unproven treatments?
In a better world we'd abolish the FDA. It does far greater harm by slowing down medical innovation than it does good by preventing bad drugs from coming on the market.
I completely agree although I don’t think the FDA should exist at all precisely because issues like this and far more and worse that the FDA has aren’t just unlucky but *predictable* given the inherent institutional incentives.
So there is evidence that for study participants who do not drop out, the placebo arm improves on average. That doesn't mean that a placebo helps patients. It could as easily be a measure of selective attrition: participants who feel worse on average may be far more likely to leave a study, and that will leave participants who are better on various measures, on average, than the study population at the beginning, AND that they were less likely to feel worse as the study proceeded. Miracle: placebo medicine helps! Or not.