Environmental Factors in Schizophrenia: The Role of Migrant Studies

Division of Psychological Medicine, Institute of Psychiatry, King's College, London.
Schizophrenia Bulletin (Impact Factor: 8.45). 08/2006; 32(3):405-8. DOI: 10.1093/schbul/sbj076
Source: PubMed


There is now compelling evidence that migrant groups in several countries have an elevated risk of developing schizophrenia and other psychotic disorders. Though the findings of earlier studies were greeted with skepticism, and ascribed by some to have methodological shortcomings and diagnostic biases, the more rigorous recent studies, from a variety of countries, have still found markedly increased incidence rates. While this phenomenon is an important health issue in its own right, understanding the reasons for the increased rates may provide valuable insights into the causes of schizophrenia and other psychotic disorders in general. The challenge for the next phase of studies is to identify the relevant risk factors and how they might interact to increase the risk of psychosis, both in migrant groups and in the general population.

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    • "This phenomenon may be more extreme for those children born in the UK of first-generation migrants than for their parents. Fearon et al. (2006) studied 568 individuals with psychosis presenting to secondary services in Nottingham, Bristol, and South East London. The results indicated remarkably high IRRs (incident rate ratios) for both schizophrenia and manic psychosis in both African-Caribbeans and Black Africans in both men and women. "
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    ABSTRACT: Cultural psychiatry research in the UK comprises a broad range of diverse methodologies, academic disciplines, and subject areas. Methodologies range from epidemiological to anthropological/ethnographic to health services research; mixed methods research is becoming increasingly popular, as are public health and health promotional topics. After briefly outlining the history of cultural psychiatry in the UK we will discuss contemporary research. Prominent themes include: the epidemiology of schizophrenia among Africans/Afro-Caribbeans, migration and mental health, racism and mental health, cultural identity, pathways to care, explanatory models of mental illness, cultural competence, and the subjective experiences of healthcare provision among specific ethnic groups such as Bangladeshis and Pakistanis. Another strand of research that is attracting increasing academic attention focuses upon the relationship between religion, spirituality, and mental health, in particular, the phenomenology of religious experience and its mental health ramifications, as well as recent work examining the complex links between theology and psychiatry. The paper ends by appraising the contributions of British cultural psychiatrists to the discipline of cultural psychiatry and suggesting promising areas for future research.
    Transcultural Psychiatry 10/2013; 50(6). DOI:10.1177/1363461513498618 · 0.99 Impact Factor
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    • "Afro-Caribbeans born in the United Kingdom have an increased risk for schizophrenia when compared with the indigenous population (e.g. Fearon et al., 2006, see also Bhui et al., 2003 for review), with the highest rates in younger British-born Afro-Caribbeans (Sugarman & Crawford, 1994) – a finding that has persisted at least to the second generation (Pinto, Ashworth, & Jones, 2008). This finding seems to extend to measures of schizotypal characteristics that are seen in non-clinical populations as well: greater proneness to psychosis in the form of delusional ideation, hallucinatory experiences, and presence of psychotic symptoms in the Afro-Caribbean healthy population have been found ( Johns, Nazroo, Bebbington, & Kuipers, 2002; King et al., 2005; Morgan et al., 2009; Sharpley & Peters, 1999). "
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    ABSTRACT: Previous research has highlighted increased risk for schizophrenia in Afro-Caribbeans as well as over-representation in the prison population. This small-scale study examined the relationship between criminality, ethnicity, and psychosis-proneness in a male prison sample. Twenty British Caucasian and 20 Afro-Caribbean prisoners were divided into equal sub-groups of violent and non-violent offenders. Participants completed measures of schizotypy, delusional ideation, and hostility. Afro-Caribbean offenders scored more highly on negative schizotypy and delusional ideation than their Caucasian counterparts. Violent offenders scored more highly on the positive symptoms of schizotypy than non-violent prisoners. Both ethnicity and violent offending may be relevant factors when considering vulnerability to psychosis in the offending population.
    06/2012; 85(2):143-9. DOI:10.1111/j.2044-8341.2011.02021.x
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    • "To date, cultural theories regarding the effect of Western exposure on eating disorder risk have focused on factors specific to eating disorders, e.g., differential media influences, peer and familial pressures on appearance, and body image ideals (Becker et al., 2002; Becker et al., 2003; Becker et al., 2011; Lynch et al., 2007; Mousa et al., 2009; Toro et al., 2006). However, migration to Western countries is also associated with increased risk for a wide range of other psychiatric disorders (Alegría et al., 2008; Breslau et al., 2008a; Cantor-Graae et al., 2005; Fearon et al., 2006) many of which are often comorbid with BED (Hudson et al., 2007; Preti et al., 2009; Swanson et al., 2011; Wonderlich et al., 2009). Increasing risk for BED might be attributable to non-specific factors that influence risk for psychopathology broadly. "
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    ABSTRACT: Exposure to Western popular culture is hypothesized to increase risk for eating disorders. This study tests this hypothesis with respect to the proposed diagnosis of binge eating disorder (BED) in an epidemiological sample of people of Mexican origin in Mexico and the U.S. Data come from the Mexico National Comorbidity Survey, National Comorbidity Survey Replication, and National Latino and Asian American Survey (N = 2268). Diagnoses were assessed with the WMH-CIDI. Six groups were compared: Mexicans with no migrant family members, Mexicans with at least one migrant family member, Mexican return-migrants, Mexican-born migrants in the U.S., and two successive generations of Mexican-Americans in the U.S. The lifetime prevalence of BED was 1.6% in Mexico and 2.2% among Mexican-Americans. Compared with Mexicans in families with migrants, risk for BED was higher in US-born Mexican-Americans with two U.S.-born parents (aHR = 2.58, 95% CI 1.12-5.93). This effect was attenuated by 24% (aHR = 1.97, 95% CI 0.84-4.62) with adjustment for prior-onset depressive or anxiety disorder. Adjustment for prior-onset conduct disorder increased the magnitude of association (aHR = 2.75, 95% CI 1.22-6.20). A similar pattern was observed for binge eating. Among respondents reporting binge eating, onset in the U.S. (vs. Mexico) was not associated with prevalence of further eating disorder symptoms. Migration from Mexico to the U.S. is associated with an increased risk for BED that may be partially attributable to non-specific influences on internalizing disorders. Among respondents reporting binge eating in either country, similar levels of further symptoms were endorsed, suggesting some cross-cultural generalizability of criteria.
    Journal of Psychiatric Research 11/2011; 46(1):31-7. DOI:10.1016/j.jpsychires.2011.10.008 · 3.96 Impact Factor
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