Low prevalence of psychoses among the Hutterites, an isolated religious community

Objective: The authors estimated the prevalence of psychoses among the Hutt erites in Manitoba, Canada, who lived in 102 communal farms or colonies. Th e study stemmed from an earlier epidemiological survey of North American Hu tterite colonies (1950-1953), in which a low prevalence of psychoses was do cumented. Method: Psychiatrically ill individuals identified during the previous surv ey were rediagnosed with DSM-IV criteria. A current provincial health insur ance claims database was queried anonymously for the period June 1992-May 1 997, and the prevalence rate of disease among Hutterites, identified by dis tinctive surnames and unique postal addresses, was compared with the rate i n the entire population of the province of Manitoba and in a comparison gro up of persons with Hutterite surnames but with addresses outside the Hutter ite colonies. Results: The annual prevalence of schizophrenia among the communal Hutterit es, estimated from the database search by using ICD-9 criteria, was consist ent with the prevalence found in the prior epidemiological survey (annual m ean of 1.2/1,000 population, compared with 1.3/1,000 in the prior survey). The database search yielded a significantly lower prevalence for schizophre nia and other functional psychoses among communal Hutterites as well as amo ng the comparison group, compared to the total Manitoba population. There w as also lower prevalence for affective psychoses and adjustment reaction di sorders among the communal Hutterites, compared to the total Manitoba popul ation. Rates for neurotic disorders were elevated both among the communal H utterites and the comparison group. Conclusions: The prevalence of specific psychoses was reduced among the Hut terites, although neurotic disorders were more prevalent. These findings su ggest some specificity, although possible artifacts such as ascertainment b ias must be considered. Further research is needed to examine genetic and e nvironmental factors that may contribute to reduced prevalence of specific psychoses among the Hutterites.