nocebo

A nocebo effect is said to occur when negative expectations of the patient regarding a treatment cause the treatment to have a more negative effect than it otherwise would have. For example, when a patient anticipates a side effect of a medication, they can experience that effect even if the "medication" is actually an inert substance. The complementary concept, the placebo effect, is said to occur when positive expectations improve an outcome. The nocebo effect is also said to occur in someone who falls ill owing to the erroneous belief that they were exposed to a toxin, e.g. SARS-CoV-2 vaccine adulterants, or to a physical phenomenon they believe is harmful, such as EM radiation.