Excess of psychoses among the French West Indian population

To investigate and compare the prevalence of psychoses in the French West Indies (FWI) and in continental France.

As part of an international epidemiologic multicentre study under the authority of the World Health Organization French Collaborating Center (WHO-CC), we questioned 7257 individuals selected from the general population in France and in the FWI, using the Mini International Neuropsychiatric Interview. We compared data using the chi-square test.

We found a significant discrepancy between the rate of psychoses at the continental French sites (1.8%) and the FWI sites (4.4%) (P < 0.0001). After homogenizing the rate of missing interviews, our results remained significant.

Such a drastic increase in the rate of psychoses in the FWI population cannot be explained solely on the basis of either the classical migration hypothesis or other currently accepted hypotheses. More attention should be given to new parameters such as 1) the recent and significant abuse of crack cocaine and cannabis in the FWI, 2) the continued existence of magic practices in a significant portion of the French Afro-Caribbean population, and 3) the expression of mood disorders with overvalued ideation or psychotic symptomatology.