Acute paranoid reaction (bouffée délirante) in Canada.

The syndrome of acute paranoid reaction is studied within the Canadian context. The main purpose of the study is to clarify its nosology and diagnostic criteria so that its diagnosis becomes more reliable and true epidemiological rates may be established. The historical development of the concept is briefly outlined in a review of the world literature, with particular attention being paid to its defining characteristics. The differential diagnosis with schizophrenia and paranoid states is of great importance given the different prognosis and treatment. Evidence from the literature is presented to show the role of sociocultural factors in the causation and diagnosis of this syndrome. Canadian data of first admissions to mental hospitals with diagnoses of reactive psychosis, including acute paranoid reaction type, for the years 1969-1973, in selected provinces, are presented. Rates of reactive psychoses as proportions of all admissions and all admission psychoses are compared with rates available for other European and Third World countries. Canadian national rates are lower and it is argued that the lower incidence is partly attributable to misdiagnosis which in turn is due to psychiatric training and to the neglect of the role attributed to sociocultural factors in the genesis of this condition.