nocebo

noun

1. (also, attributive)A substance which a patient experiences as harmful due to a previous negative perception, but which is in fact pharmacologically (medicinally) inactive.

   “It is somewhat surprising that little attention has been drawn to the existence of the contrary effect [to the placebo] – which I may call the nocebo reaction.”

   “In the case of the nocebo, it is negative expectations that become self-fulfilling prophecies.”

   “It seems to be a "nocebo" effect – the self-diagnosed gluten sensitive patients expected to feel worse on the study diets, so they did.”

   “If there's one lesson to be drawn from the nocebo effect, it's that ideas are never merely ideas. […] Maybe you see where I'm going with this: our grim view of humanity is also a nocebo.”