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Schofield P, Thygesen M, Das-Munshi J, Becares L, Cantor-Graae E, Pedersen C, Agerbo E. Ethnic density, urbanicity and psychosis risk for migrant groups - A population cohort study. Schizophr Res 2017; 190:82-87. [PMID: 28318842 PMCID: PMC5735221 DOI: 10.1016/j.schres.2017.03.032] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/10/2017] [Accepted: 03/11/2017] [Indexed: 12/29/2022]
Abstract
BACKGROUND Rates of psychotic disorder are raised for many migrant groups. Understanding the role played by the social context in which they live may help explain why. This study investigates the effect of both neighbourhood ethnic density and urbanicity on the incidence of non-affective psychosis for migrant groups. METHOD Population based cohort of all those born 1965 or later followed from their 15th birthday (2,224,464 people) to 1st July 2013 (37,335,812 person years). Neighbourhood exposures were measured at age 15. RESULTS For all groups incidence of non-affective psychosis was greater in lower ethnic density neighbourhoods. For migrants of African origin there was a 1.94-fold increase (95% CI, 1.17-3.23) comparing lowest and highest density quintiles; with similar effects for migrants from Europe (excluding Scandinavia): incidence rate ratio (IRR) 1.99 (95% CI, 1.56-2.54); Asia: IRR 1.63 (95% CI, 1.02-2.59); and the Middle East: IRR 1.68 (95% CI, 1.19-2.38). This initial analysis found no evidence for an urbanicity effect for migrant groups. Adjusting for ethnic density revealed a positive association between level of urbanicity and psychosis for two groups, with a statistically significant linear trend (average effect of a one quintile increase) for migrants from Europe: IRR 1.09 (95% CI, 1.02-1.16) and the Middle East: IRR 1.12 (95% CI, 1.01-1.23). CONCLUSIONS In this first nationwide population-based study of ethnic density, urbanicity and psychosis we show that lower ethnic density is associated with increased incidence of non-affective psychosis for different migrant groups; masking urban/rural differences in psychosis for some groups.
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Affiliation(s)
- Peter Schofield
- Division of Health & Social Care Research, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom.
| | - Malene Thygesen
- Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark,National Centre for Register-Based Research, Aarhus University, Aarhus, Denmark,CIRRAU - Centre for Integrated Register-based Research at Aarhus University, Aarhus, Denmark
| | - Jay Das-Munshi
- Health Service & Population Research Department, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Laia Becares
- Centre on Dynamics of Ethnicity, The University of Manchester, Manchester, United Kingdom
| | | | - Carsten Pedersen
- Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark,National Centre for Register-Based Research, Aarhus University, Aarhus, Denmark,CIRRAU - Centre for Integrated Register-based Research at Aarhus University, Aarhus, Denmark
| | - Esben Agerbo
- Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark,National Centre for Register-Based Research, Aarhus University, Aarhus, Denmark,CIRRAU - Centre for Integrated Register-based Research at Aarhus University, Aarhus, Denmark
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Mustelin L, Hedman AM, Thornton LM, Kuja-Halkola R, Keski-Rahkonen A, Cantor-Graae E, Almqvist C, Birgegård A, Lichtenstein P, Mortensen PB, Pedersen CB, Bulik CM. Risk of eating disorders in immigrant populations. Acta Psychiatr Scand 2017; 136:156-165. [PMID: 28542783 DOI: 10.1111/acps.12750] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/17/2017] [Indexed: 12/16/2022]
Abstract
OBJECTIVE The risk of certain psychiatric disorders is elevated among immigrants. To date, no population studies on immigrant health have addressed eating disorders. We examined whether risk of eating disorders in first- and second-generation immigrants differs from native-born Danes and Swedes. METHOD All individuals born 1984-2002 (Danish cohort) and 1989-1999 (Swedish cohort) and residing in the respective country on their 10th birthday were included. They were followed up for the development of eating disorders based on out-patient and in-patient data. RESULTS The risks of all eating disorder types were lower among first-generation immigrants compared to the native populations: Incidence-rate ratio (95% confidence interval) was 0.39 (0.29, 0.51) for anorexia nervosa, 0.60 (0.42, 0.83) for bulimia nervosa, and 0.62 (0.47, 0.79) for other eating disorders in Denmark and 0.27 (0.21, 0.34) for anorexia nervosa, 0.30 (0.18, 0.51) for bulimia nervosa, and 0.39 (0.32, 0.47) for other eating disorders in Sweden. Likewise, second-generation immigrants by both parents were at lower risk, whereas those with only one foreign-born parent were not. CONCLUSION The decreased risk of eating disorders among immigrants is opposite to what has been observed for other psychiatric disorders, particularly schizophrenia. Possible explanations include buffering sociocultural factors and underdetection in health care.
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Affiliation(s)
- L Mustelin
- Departments of Psychiatry and Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Department of Public Health, University of Helsinki, Helsinki, Finland.,Institute for Molecular Medicine Finland FIMM, University of Helsinki, Helsinki, Finland
| | - A M Hedman
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - L M Thornton
- Departments of Psychiatry and Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - R Kuja-Halkola
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - A Keski-Rahkonen
- Department of Public Health, University of Helsinki, Helsinki, Finland
| | - E Cantor-Graae
- Social Medicine and Global Health, Lund University, Malmö, Sweden
| | - C Almqvist
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - A Birgegård
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet & Stockholm Health Care Services, Stockholm County Council, Stockholm, Sweden
| | - P Lichtenstein
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - P B Mortensen
- National Centre for Register-based Research, School of Business and Social Sciences, Aarhus University, Aarhus, Denmark.,Centre for Integrated Register-based Research, CIRRAU, Aarhus University, Aarhus, Denmark.,The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
| | - C B Pedersen
- National Centre for Register-based Research, School of Business and Social Sciences, Aarhus University, Aarhus, Denmark.,Centre for Integrated Register-based Research, CIRRAU, Aarhus University, Aarhus, Denmark.,The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
| | - C M Bulik
- Departments of Psychiatry and Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
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Patel K, Kouvonen A, Close C, Väänänen A, O'Reilly D, Donnelly M. What do register-based studies tell us about migrant mental health? A scoping review. Syst Rev 2017; 6:78. [PMID: 28399907 PMCID: PMC5387245 DOI: 10.1186/s13643-017-0463-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 03/23/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Previous studies investigating the mental health of migrants have shown mixed results. The increased availability of register data has led to a growing number of register-based studies in this research area. This is the first scoping review on the use of registry and record-linkage data to examine the mental health of migrant populations. The aim of this scoping review is to investigate the topics covered and to assess the results yielded from these studies. METHODS We used a scoping review methodology to search MedLine, PubMed, PsychINFO, Web of Science, and SCOPUS for all register-based studies on the mental health of migrants. Two reviewers screened all papers, independently, using iteratively applied inclusion and exclusion criteria. Using gradually broadening inclusion and exclusion criteria for maximum "scope," newly published criteria developed to appraise the methodological quality of record-linkage studies were applied to eligible papers and data were extracted in a charting exercise. RESULTS A total of 1309 papers were screened and appraised, 51 of which met the eligibility and quality criteria and were included in the review. This review identified four major domains of register-based research within the topic of migrant mental health: rates and risks of psychiatric disorders, rates and risks of suicide mortality, the use of psychotropic drugs, and health service utilisation and mental health-related hospitalisation rates. We found that whilst migrants can be at an increased risk of developing psychotic disorders and suicide mortality, they are less likely to use psychotropic medication and mental health-related services. CONCLUSIONS This review systematically charts the register-based studies on migrants' mental health for the first time. It shows the main topics and gaps in knowledge in this research domain, discusses the disadvantages of register-based studies, and suggests new directions for forthcoming studies.
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Affiliation(s)
- Kishan Patel
- Administrative Data Research Centre (Northern Ireland), Centre for Public Health, Queen's University Belfast, Belfast, UK.
| | - Anne Kouvonen
- Administrative Data Research Centre (Northern Ireland), Centre for Public Health, Queen's University Belfast, Belfast, UK.,Department of Social Research, University of Helsinki, Helsinki, Finland.,SWPS University of Social Sciences and Humanities in Wroclaw, Wroclaw, Poland
| | - Ciara Close
- Administrative Data Research Centre (Northern Ireland), Centre for Public Health, Queen's University Belfast, Belfast, UK
| | - Ari Väänänen
- Finnish Institute of Occupational Health, Helsinki, Finland
| | - Dermot O'Reilly
- Administrative Data Research Centre (Northern Ireland), Centre for Public Health, Queen's University Belfast, Belfast, UK.,UKCRC Centre of Excellence for Public Health, Queen's University Belfast, Belfast, UK
| | - Michael Donnelly
- Administrative Data Research Centre (Northern Ireland), Centre for Public Health, Queen's University Belfast, Belfast, UK.,UKCRC Centre of Excellence for Public Health, Queen's University Belfast, Belfast, UK
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Waltoft BL, Pedersen CB, Nyegaard M, Hobolth A. The importance of distinguishing between the odds ratio and the incidence rate ratio in GWAS. BMC MEDICAL GENETICS 2015; 16:71. [PMID: 26319230 PMCID: PMC4593225 DOI: 10.1186/s12881-015-0210-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 08/10/2015] [Indexed: 11/22/2022]
Abstract
Background In recent years, genome wide association studies have identified many genetic variants that are consistently associated with common complex diseases, but the amount of heritability explained by these risk alleles is still low. Part of the missing heritability may be due to genetic heterogeneity and small sample sizes, but non-optimal study designs in many genome wide association studies may also have contributed to the failure of identifying gene variants causing a predisposition to disease. The normally used odds ratio from a classical case-control study measures the association between genotype and being diseased. In comparison, under incidence density sampling, the incidence rate ratio measures the association between genotype and becoming diseased. We estimate the differences between the odds ratio and the incidence rate ratio under the presence of events precluding the disease of interest. Such events may arise due to pleiotropy and are known as competing events. In addition, we investigate how these differences impact the association test. Methods We simulate life spans of individuals whose gene variants are subject to competing events. To estimate the association between genotype and disease, we applied classical case-control studies and incidence density sampling. Results We find significant numerical differences between the odds ratio and the incidence rate ratio when the fact that gene variant may be associated with competing events, e.g. lifetime, is ignored. The only scenario showing little or no difference is an association with a rare disease and no other present associations. Furthermore, we find that p-values for association tests differed between the two study designs. Conclusions If the interest is on the aetiology of the disease, a design based on incidence density sampling provides the preferred interpretation of the estimate. Under a classical case-control design and in the presence of competing events, the change in p-values in the association test may lead to false positive findings and, more importantly, false negative findings. The ranking of the SNPs according to p-values may differ between the two study designs. Electronic supplementary material The online version of this article (doi:10.1186/s12881-015-0210-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Berit Lindum Waltoft
- National Center for Register-based Research, Department of Economics and Business Economics, Aarhus University, Fuglesangs allé 4 room K10, 8210, Aarhus V, Denmark. .,The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark. .,Bioinformatics Research Center, Aarhus University, C.F. Møllers Allé 8, 8000, Aarhus C, Denmark.
| | - Carsten Bøcker Pedersen
- National Center for Register-based Research, Department of Economics and Business Economics, Aarhus University, Fuglesangs allé 4 room K10, 8210, Aarhus V, Denmark. .,The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark. .,The Centre for Integrated Register-based Research, Aarhus University, CIRRAU, Arhus University, Aarhus, Denmark.
| | - Mette Nyegaard
- The Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark. .,Department of Biomedicine, Aarhus University, Vennelyst Boulevard 4, 8000, Aarhus C, Denmark.
| | - Asger Hobolth
- Bioinformatics Research Center, Aarhus University, C.F. Møllers Allé 8, 8000, Aarhus C, Denmark.
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van der Ven E, Dalman C, Wicks S, Allebeck P, Magnusson C, van Os J, Selten JP. Testing Ødegaard's selective migration hypothesis: a longitudinal cohort study of risk factors for non-affective psychotic disorders among prospective emigrants. Psychol Med 2015; 45:727-734. [PMID: 25084213 DOI: 10.1017/s0033291714001780] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND The selection hypothesis posits that the increased rates of psychosis observed among migrants are due to selective migration of people who are predisposed to develop the disorder. To test this hypothesis, we examined whether risk factors for psychosis are more prevalent among future emigrants. METHOD A cohort of 49,321 Swedish military conscripts was assessed at age 18 years on cannabis use, IQ, psychiatric diagnosis, social adjustment, history of trauma and urbanicity of place of upbringing. Through data linkage we examined whether these exposures predicted emigration out of Sweden. We also calculated the emigrants' hypothetical relative risk compared with non-emigrants for developing a non-affective psychotic disorder. RESULTS Low IQ [odds ratio (OR) 0.5, 95% confidence interval (95% CI) 0.3-0.9] and 'poor social adjustment' (OR 0.4, 95% CI 0.2-0.8) were significantly less prevalent among prospective emigrants, whereas a history of urban upbringing (OR 2.3, 95% CI 1.4-3.7) was significantly more common. Apart from a non-significant increase in cannabis use among emigrants (OR 1.6, 95% CI 0.8-3.1), there were no major group differences in any other risk factors. Compared to non-emigrants, hypothetical relative risks for developing non-affective psychotic disorder were 0.7 (95% CI 0.4-1.2) and 0.8 (95% CI 0.7-1.0), respectively, for emigrants narrowly and broadly defined. CONCLUSIONS This study adds to an increasing body of evidence opposing the selection hypothesis.
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Affiliation(s)
- E van der Ven
- Maastricht University,School for Mental Health and Neuroscience, Maastricht,The Netherlands
| | - C Dalman
- Public Health Epidemiology, Department of Public Health Sciences,Karolinska Institutet,Stockholm,Sweden
| | - S Wicks
- Public Health Epidemiology, Department of Public Health Sciences,Karolinska Institutet,Stockholm,Sweden
| | - P Allebeck
- Social Medicine, Department of Public Health Sciences,Karolinska Institutet, Stockholm,Sweden
| | - C Magnusson
- Public Health Epidemiology, Department of Public Health Sciences,Karolinska Institutet,Stockholm,Sweden
| | - J van Os
- Maastricht University,School for Mental Health and Neuroscience, Maastricht,The Netherlands
| | - J P Selten
- Maastricht University,School for Mental Health and Neuroscience, Maastricht,The Netherlands
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6
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Differences in Psychopathology Between Immigrant and Native Adolescents Admitted to a Psychiatric Inpatient Unit. J Immigr Minor Health 2014; 17:1715-22. [DOI: 10.1007/s10903-014-0143-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Mura G, Petretto DR, Bhat KM, Carta MG. Schizophrenia: from epidemiology to rehabilitation. Clin Pract Epidemiol Ment Health 2012; 8:52-66. [PMID: 22962559 PMCID: PMC3434422 DOI: 10.2174/1745017901208010052] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2011] [Revised: 12/26/2011] [Accepted: 01/01/2012] [Indexed: 12/27/2022]
Abstract
Purpose/Objective: We discuss recent evidences about schizophrenia (frequency, onset, course, risk factors and genetics) and their influences to some epidemiological myths about schizophrenia diffuse between psychiatric and psychopathology clinicians. The scope is to evaluate if the new acquisitions may change the rehabilitation approaches to schizophrenia modifying the balance about the neurodevelopmental hypothesis of schizophrenia accepting that the cognitive deficits are produced by errors during the normal development of the brain (neurodevelopmental hypothesis) that remains stable in the course of illness and the neurodegenerative hypothesis according of which they derived from a degenerative process that goes on inexorably. Research Method/Design: A review of the literature about epidemiology of schizophrenia has been performed and the contributions of some of these evidence to neurodevelopmental hypothesis and to rehabilitation has been described. Results: It cannot be definitively concluded for or against the neurodevelopmental or degenerative hypothesis, but efforts in understanding basis of schizophrenia must go on. Until now, rehabilitation programs are based on the vulnerability-stress model: supposing an early deficit that go on stable during the life under favorable circumstances. So, rehabilitation approaches (as neuro-cognitive approaches, social skill training, cognitive-emotional training) are focused on the individual and micro-group coping skills, aiming to help people with schizophrenia to cope with environmental stress factors. Conclusions/Implications: Coping of cognitive deficits in schizophrenia may represents the starting-point for further research on schizophrenia, cohort studies and randomized trials are necessary to defined the range of effectiveness and the outcome of the treatments.
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Affiliation(s)
- Gioia Mura
- Consultation Liaison Psychiatric Unit at the University Hospital of Cagliari, University of Cagliari and AOU Cagliari - Italy
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Pedersen CB, Demontis D, Pedersen MS, Agerbo E, Mortensen PB, Børglum AD, Hougaard DM, Hollegaard MV, Mors O, Cantor-Graae E. Risk of schizophrenia in relation to parental origin and genome-wide divergence. Psychol Med 2012; 42:1515-1521. [PMID: 22067478 DOI: 10.1017/s0033291711002376] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Second-generation immigrants have an increased risk of schizophrenia, a finding that still lacks a satisfactory explanation. Various operational definitions of second-generation immigrants have been used, including foreign parental country of birth. However, with increasing global migration, it is not clear that parental country of birth necessarily is informative with regard to ethnicity. We compare two independently collected measures of parental foreign ethnicity, parental foreign country of birth versus genetic divergence, based on genome-wide genotypic data, to access which measure most efficiently captures the increased risk of schizophrenia among second-generation immigrants residing in Denmark. METHOD A case-control study covering all children born in Denmark since 1981 included 892 cases of schizophrenia and 883 matched controls. Genetic divergence was assessed using principal component analyses of the genotypic data. Independently, parental foreign country of birth was assessed using information recorded prospectively in the Danish Civil Registration System. We compared incidence rate ratios of schizophrenia associated with these two independently collected measures of parental foreign ethnicity. RESULTS People with foreign-born parents had a significantly increased risk of schizophrenia [relative risk (RR) 1.94 (95% confidence intervals (CI) 1.41-2.65)]. Genetically divergent persons also had a significant increased risk [RR 2.43 (95% CI 1.55-3.82)]. Mutual adjustment of parental foreign country of birth and genetic divergence showed no difference between these measures with regard to their potential impact on the results. CONCLUSIONS In terms of RR of schizophrenia, genetic divergence and parental foreign country of birth are interchangeable entities, and both entities have validity with regard to identifying second-generation immigrants.
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Affiliation(s)
- C B Pedersen
- National Centre for Register-based-Research, Aarhus University, Aarhus, Denmark.
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Qian K, Di Lieto A, Corander J, Auvinen P, Greco D. Re-analysis of Bipolar Disorder and Schizophrenia Gene Expression Complements the Kraepelinian Dichotomy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 736:563-77. [DOI: 10.1007/978-1-4419-7210-1_33] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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