Varicella vaccine seen in children. The incidence of herpes zoster in vaccinated adults is 0.9/1000 person-years, and is 0.33/1000 person-years in vaccinated children; this is lower than the overall incidence of 3.2–4.2/1000 person-years. Adult shingles cases may increase after introduction of varicella vaccine, but evidence is unclear. While research using computer models has tended to support the hypothesis that vaccination programs would increase incidence of zoster in the short term, the evidence from epidemiological studies is mixed, and increases observed in zoster incidence in some studies may not be related to vaccination programs, as the incidence increases prior to the varicella vaccine
Psychogenic disease to be psychogenic include psychogenic seizures, psychogenic polydipsia, psychogenic tremor, and psychogenic pain. There are problems with the assumption that all medically unexplained illness must have a psychological cause. It always remains possible that genetic, biochemical, electrophysiological, or other abnormalities may be present which we do not have the technology or background to identify. The term "psychogenic disease" is often used in a similar way to "psychosomatic disease". However, the term "psychogenic" usually implies that psychological factors played a key causal role in the development of the illness. The term "psychosomatic" is often used in a broader way to describe