Ok, I'll be more specific: the reason why drug trials are placebo-controlled is that human body is already equipped with the most miraculous drug of all: our ow

Ok, I'll be more specific: the reason why drug trials are placebo-controlled is that human body is already equipped with the most miraculous drug of all: our own immune system. So, to accurately measure effectiveness of the drug we have to benchmark it against effectiveness of immune system. Placebo effect is just our own body fighting disease, no mystical forces involved.