Content area
Full Text
Soc Psychiatry Psychiatr Epidemiol (2008) 43:937939 DOI 10.1007/s00127-008-0390-5
EDITORIAL
Jean-Paul Selten Hans W. Hoek
Does misdiagnosis explain the schizophrenia epidemic among immigrants from developing countries to Western Europe?
Published online: 28 June 2008
A number of studies have found consistent evidence of an increased incidence of schizophrenia among rst- and second-generation immigrants from developing countries to Western Europe. According to a meta-analysis [2] the mean weighted relative risk (RR) for these immigrants, compared to the risk for natives, was 3.3 (95% Condence Interval [95% CI]:2.83.9). The risks differed greatly, however, among the various ethnic groups, with the greatest risks relating to the least successful immigrations (e.g., AfricanCaribbeans in the UK, Moroccan males in the Netherlands, Inuit in Denmark). The meta-analysis found no evidence that these ndings were accounted for by misdiagnosis, because the studies that used semi-structured diagnostic interviews and the studies that used other diagnostic methods yielded similarly signicant results (RR 3.4; 95% CI: 2.34.9; RR 2.8; 95% CI: 2.43.4, respectively).
Nonetheless, these ndings have always been disputed. Thus some researchers have claimed that the
putative increase of schizophrenia was accounted for by a misdiagnosis of normal cultural beliefs [11], acute psychotic reactions [8] or non-affective remitting psychoses with a good prognosis [6]. However, they have failed to produce evidence in support of this. Follow-up studies in the UK and in the Netherlands have shown that these psychoses were not more often brief or remitting than in the group of natives. The two studies that re-examined subjects 23 years after the rst psychotic episode found no evidence of greater diagnostic instability in the groups of immigrants and the proportions of patients who had been continuously psychotic were remarkably similar across groups [4, 17]. In addition, the growing number of reports of a higher prevalence of non-clinical psychotic symptoms in immigrant groups known for their high schizophrenia risk is consistent with the idea of a greater force of morbidity acting upon these groups [7, 16]. Thus, it seems that the increase encompasses the whole psychosis spectrum, from non-clinical psychotic symptoms at one end to chronic schizophrenia at the other.
Mood disorders?
A variation upon the misdiagnosis theme is the suggestion that the excess of schizophrenia is due to misdiagnosis of mood disorders. In this journal,...