"Lying to patients is almost always unethical. But, in order for placebos to work, we have to believe they are “real” treatments, which means the doctor would have to lie to us and say that the placebo was actually a real treatment. Or, in the case of a clinical trial, that it might be a real treatment. After all, if a doctor handed you a pill and said, “this is just a sugar pill”, you’d probably assume it wouldn’t work. But sometimes our assumptions are mistaken."