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BACKGROUND Cannabis use may be a risk factor for schizophrenia. Part of this association may be explained by genotype-environment interaction, and part of it by genotype-environment correlation. The latter issue has not been explored. We investigated whether cannabis use is associated with schizophrenia, and whether gene-environment correlation contributes(More)
There is only one previous report on the first-contact incidence of schizophrenia among immigrants in the Netherlands, which was based on a small number of cases, particularly for second generation immigrants. We conducted another two-year first-contact incidence study in the same geographical area, combined the data of both studies and compared risks over(More)
PURPOSE OF REVIEW This article reviews the recent literature about migration, ethnic minority position and the risk of psychotic disorders. RECENT FINDINGS A meta-analysis found that both first and second-generation migrants have on average a two-fold increase in risk for psychotic disorders. In the Netherlands, the risk was most elevated for individuals(More)
BACKGROUND Ethnic minority position is associated with increased risk for psychotic outcomes, which may be mediated by experiences of social exclusion, defeat and discrimination. Sexual minorities are subject to similar stressors. The aim of this study is to examine whether sexual minorities are at increased risk for psychotic symptoms and to explore(More)
OBJECTIVE A high incidence of psychotic disorders has been reported in immigrant ethnic groups in Western Europe. Some studies suggest that ethnic density may influence the incidence of schizophrenia. The authors investigated whether this increased incidence among immigrants depends on the ethnic density of the neighborhoods in which they live. METHOD(More)
The incidence of schizophrenia and other psychotic disorders is very high among several ethnic minority groups in the Netherlands, and is most increased for Moroccans. This study compared symptoms at first treatment contact for a psychotic disorder between 117 native Dutch and 165 ethnic minority patients from Morocco, Surinam, Turkey, other non-Western(More)
OBJECTIVE The purpose of this study was to examine whether the increased risk for developing a psychotic disorder among immigrants is related to their age at the time of migration. METHOD In a 7-year first-contact incidence study, immigrants to the Netherlands and Dutch citizens, ages 15-54 years, who made a first contact with a physician for a suspected(More)
The impact of social environments on mental states is difficult to assess, limiting the understanding of which aspects of the social environment contribute to the onset of psychotic symptoms and how individual characteristics moderate this outcome. This study aimed to test sensitivity to environmental social stress as a mechanism of psychosis using Virtual(More)
BACKGROUND Previous studies have reported a very high incidence of schizophrenia for immigrant ethnic groups in Western Europe. The explanation of these findings is unknown, but is likely to involve social stress inherent to the migrant condition. A previous study reported that the incidence of schizophrenia in ethnic groups was higher when these groups(More)
A Virtual Reality (VR) environment was created to study psychotic symptoms in patients and non-patients. Participants' task was to find five virtual characters that each had a small number label on his or her chest. The density and ethnic appearance of the virtual characters in the bar was controlled. For a non-patient group (N=24), results showed a(More)