Schizophrenia is one of the most common, most devastating, and most enigmatic of the disorders that plague humankind. About 3 in 1000 people suffer from this disorder at a given time (prevalence: 0.3%), and about 1 in 100 people will be afflicted by the disorder within a year (incidence: 1%). As far as is known, schizophrenia exists in all cultures (with a ten-fold variation of frequency) and has been present throughout history, at least as long as there are records from which some direct or indirect evidence can be derived.