Nocebo Effect


A negative Placebo effect; when patients taking medications experience undesired side effects unrelated to the specific actions of a drug or treatment. The nocebo effect is caused by the person's prior expectations of undesirable effects from treatment as well as conditioning in which the person learns from prior experiences to associate a medication with certain somatic symptoms.[1] [2] [3]


The term "nocebo" means "I will harm." It was coined in the 1960's and the phenomenon has been less studied than the placebo effect.

Applications in Anthropology

In anthropology nocebos/placebos are almost always culturally bound; they do not exist in a vacuum. Their effects always depend on a wider context of cultural beliefs, expectations, assumptions, and norms as well as rely on certain economic realities in which they occur. Context defines and/or validates the healing powers of the placebo and the potential harm associated with nocebo Placebos are subject to cultural relativism, as one placebo may be effective in one cultural group but not in another.[4]

When western anthropologists first heard reports of witch doctors who could issue deadly curses, they quickly found rational explanations for this phenomena. The families of the cursed often felt there was no point using resources on the "walking dead," and as a result, many of the "cursed" would die from starvation. The nocebo effect is influential in the way people are treated. "Voodoo death" may represent an extreme form of the nocebo phenomenon," says anthropologist Robert Hahn of the US Centers for Disease Control and Prevention in Atlanta, Georgia, who has studied the nocebo effect.[5]


Experiments have been conducted that illustrate how the nocebo effect works. One example is when more than two-thirds of 34 college students developed headaches when told that a non-existent electrical current passing through their heads could produce a headache.

In another experiment, asthmatic patients breathed in a vapor that researchers told them was a chemical irritant or allergen. Nearly half of the patients experienced breathing problems, with a dozen developing full-blown attacks. They were “treated” with a substance they believed to be a bronchodilating medicine, and recovered immediately. In actuality, both the “irritant” and the “medicine” were a nebulized saltwater solution.

Case Study

Late one night in a small Alabama cemetery, Vance Vanders had a run-in with the local witch doctor, who wafted a bottle of unpleasant-smelling liquid in front of his face, and told him he was about to die and that no one could save him.

Back home, Vanders took to his bed and began to deteriorate. Some weeks later, emaciated and near death, he was admitted to the local hospital, where doctors were unable to find a cause for his symptoms or slow his decline. Only then did his wife tell one of the doctors, Drayton Doherty, of the hex. Doherty thought long and hard. The next morning, he called Vanders's family to his bedside. He told them that the previous night he had lured the witch doctor back to the cemetery, where he had choked him against a tree until he explained how the curse worked. The medicine man had, he said, rubbed lizard eggs into Vanders's stomach, which had hatched inside his body. One reptile remained, which was eating Vanders from the inside out.

Doherty then summoned a nurse who had, by prior arrangement, filled a large syringe with a powerful emetic. With great ceremony, he inspected the instrument and injected its contents into Vanders' arm. A few minutes later, Vanders began to gag and vomit uncontrollably. In the midst of it all, unnoticed by everyone in the room, Doherty produced his pièce de résistance - a green lizard he had stashed in his black bag. "Look what has come out of you Vance," he cried. "The voodoo curse is lifted. Vanders did a double take, lurched backwards to the head of the bed, then drifted into a deep sleep. When he woke next day he was alert and ravenous. He quickly regained his strength and was discharged a week later.

The facts of this case from 80 years ago were corroborated by four medical professionals. Perhaps the most remarkable thing about it is that Vanders survived. There are numerous documented instances from many parts of the globe of people dying after being cursed. With no medical records and no autopsy results, there's no way to be sure exactly how these people met their end. The common thread in these cases, however, is that a respected figure puts a curse on someone, perhaps by chanting or pointing a bone at them. Soon afterwards, the victim dies, apparently of natural causes.


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  1. ^ "Nocebo and Nocebo Effect." The Skeptic's Dictionary - 27 Apr. 2010.
  2. ^ Peter, David (2001) Understanding the Placebo Affect in Complementary Medicine: Theory, Practice, and Research. London:Harcourt Publishers
  3. ^ "Nocebo." Priory Medical Journals Online. 27 Apr. 2010.
  4. ^ Sjaakvan der Geest and Anita Hardon (2006) Social and cultural efficacies of medicines: Complications forantiretroviral therapy
  5. ^ Pilcher, Helen (2009) The Science of Voodoo: When Mind Attacks Body. New Scientist. 2708.