education, media work, and other discourse makers who induce health anxiety and negative expectations. Electromagnetic hypersensitivity Evidence suggests that the symptoms of electromagnetic hypersensitivity are caused by the nocebo effect. Pain Verbal suggestion can cause hyperalgesia (increased sensitivity to pain) and allodynia (perception of a tactile stimulus as painful) as a result of the nocebo effect. Nocebo hyperalgesia is believed to involve the activation of cholecystokinin receptors. Ambiguity of medical usage Stewart-Williams and Podd argue that using the contrasting terms "placebo" and "nocebo" to label inert agents that produce pleasant, health-improving, or desirable outcomes versus unpleasant, health-diminishing, or undesirable outcomes (respectively), is extremely counterproductive. For example, precisely the same inert agents can produce analgesia and hyperalgesia, the first of which, from this definition, would be a placebo, and the second a nocebo. A second problem is that the same effect, such as immunosuppression, may be desirable for a subject with an autoimmune disorder, but be undesirable for most other subjects. Thus, in the first case, the effect would be a placebo, and in the second, a nocebo. A third problem is that the prescriber does not know whether the relevant subjects consider the effects that they experience to be desirable or undesirable until some time after the drugs have been administered. A fourth problem is that the same phenomena are being generated in all the subjects, and these are being generated by the same drug, which is acting in all of the subjects through the same mechanism. Yet because the phenomena in question have been subjectively considered to be desirable to one group but not the other, the phenomena are now being labelled in two mutually exclusive ways (i.e., placebo and nocebo); and this is giving the false impression that the drug in question has produced two different phenomena. Ambiguity of anthropological usage Some people maintain that belief kills (e.g., voodoo death: Cannon in 1942 describes a number of instances from a variety of different cultures) and belief heals (e.g., faith healing). A self-willed death (due to voodoo hex, evil eye, pointing the bone procedure, etc.) is an extreme form of a culture-specific syndrome or mass psychogenic illness that produces a particular form of psychosomatic or psychophysiological disorder which results in a psychogenic death. Rubel in 1964 spoke of "culture bound" syndromes, which were those "from which members of a particular group claim to suffer and for which their culture