A ONE-YEAR PREVALENCE STUDY OF SCHIZOPHRENIA ON REUNION ISLAND

Review of geographical comparisons of the prevalence of schizophrenic disorders found a ten-fold range difference between geographical conti guous groups, with high and low prevalence pockets. We performed a I-y ear prevalence study of schizophrenia in a limited area of Reunion Isl and in the Indian Ocean, and analysed the prevalence variability in co ntiguous regions of this area. We found one of the highest reported ag e-corrected (above 15 years) 1-year prevalence of schizophrenia (14.9 per thousand). Large discrepancies in the distribution of prevalence r ates of schizophrenia were observed between the five towns analysed. I nterestingly, when a higher prevalence was observed, it was highly cor related with an increase of the percentage of familial cases (r = 0.98 9, df = 3, P = 0.0014). Presence of founder effect often described in geographical isolates could explain the high prevalence rate and the h eterogeneity between towns observed in our sample.