Vidhika Gadia Mass Psychogenic Illness (MPI), also known as mass sociogenic illness is defined as the rapid spread of illness signs and symptoms affecting members of a cohesive group, originating from a nervous system disturbance involving excitation, loss, or alteration of function, whereby physical complaints that are exhibited unconsciously have no corresponding organic etiology” (Bartholomew, 2002). In other words, it involved the spread of symptoms of illnesses through a certain group or population where there is no organic or environmental cause for the symptoms. It differs from delusions as it involves physical symptoms. For the standard psychiatric nomenclature, mass psychogenic illnesses are under the general heading of “somatoform disorder”, and are subcategorised as “conversion disorder” or “hysterical neurosis, conversion type” (Bartholomew, 2002). Two types of mass psychogenic illness have been defined, the first being ‘Mass Anxiety Hyste...