ABSTRACT
Before discussing the nature of placebo effects in more detail, the reader’s attention should be drawn to the existence of the placebo’s wicked alter ego, the so-called nocebo (which translates as ‘I will harm’). Whereas placebos lead to positive effects, nocebos lead to negative effects. Thus if sugar pills are administered to a group of people and they are told that, say, headaches or drowsiness may result, a sizeable proportion of the group may well report such effects. Even less research has been directed towards understanding the nocebo effect than towards the placebo effect, but it seems likely that similar explanations may apply to both phenomena (Benson, 1997; Hahn, 1997a, b; Spiegel, 1997; Wynder, 1997). It is claimed that, as with placebos, effects can vary from slight to extremely strong. Indeed, in the most extreme case, claims that voodoo curses can actually lead to death have been explained in terms of extreme nocebo reactions!
