Sam Vaknin. (№ 462684)

Quote Explanation: Mass psychogenic illness. Mass psychogenic illness (MPI) is the spread of symptoms of an illness among a population in which there is no infectious agent responsible for the infection. it is a rapid spread of signs and symptoms of disease affecting members of a cohesive group, arising from a disturbance of the nervous system, including agitation, loss or change of functions, while physical complaints that appear unconsciously do not have a corresponding organic etiology.