title: Refugee migration and risk of schizophrenia and other non-affective psychoses: cohort study of 1.3 million people in Sweden.
abstract: OBJECTIVE
  To determine whether refugees are at elevated risk of schizophrenia and other non-affective psychotic disorders, relative to non-refugee migrants from similar regions of origin and the Swedish-born population.
  
  
  METHODS
  Cohort study of people living in Sweden, born after 1 January 1984 and followed from their 14th birthday or arrival in Sweden, if later, until diagnosis of a non-affective psychotic disorder, emigration, death, or 31 December 2011.
  
  
  METHODS
  Linked Swedish national register data.
  
  
  METHODS
  1,347,790 people, including people born in Sweden to two Swedish-born parents (1,191,004; 88.4%), refugees (24,123; 1.8%), and non-refugee migrants (132,663; 9.8%) from four major refugee generating regions: the Middle East and north Africa, sub-Saharan Africa, Asia, and Eastern Europe and Russia.
  
  
  METHODS
  Cox regression analysis was used to estimate adjusted hazard ratios for non-affective psychotic disorders by refugee status and region of origin, controlling for age at risk, sex, disposable income, and population density.
  
  
  RESULTS
  3704 cases of non-affective psychotic disorder were identified during 8.9 million person years of follow-up. The crude incidence rate was 38.5 (95% confidence interval 37.2 to 39.9) per 100,000 person years in the Swedish-born population, 80.4 (72.7 to 88.9) per 100,000 person years in non-refugee migrants, and 126.4 (103.1 to 154.8) per 100,000 person years in refugees. Refugees were at increased risk of psychosis compared with both the Swedish-born population (adjusted hazard ratio 2.9, 95% confidence interval 2.3 to 3.6) and non-refugee migrants (1.7, 1.3 to 2.1) after adjustment for confounders. The increased rate in refugees compared with non-refugee migrants was more pronounced in men (likelihood ratio test for interaction χ(2) (df=2) z=13.5; P=0.001) and was present for refugees from all regions except sub-Saharan Africa. Both refugees and non-refugee migrants from sub-Saharan Africa had similarly high rates relative to the Swedish-born population.
  
  
  CONCLUSIONS
  Refugees face an increased risk of schizophrenia and other non-affective psychotic disorders compared with non-refugee migrants from similar regions of origin and the native-born Swedish population. Clinicians and health service planners in refugee receiving countries should be aware of a raised risk of psychosis in addition to other mental and physical health inequalities experienced by refugees.
authors.affiliation: Department of Public Health Sciences, Karolinska Institutet, 171 77 Stockholm, Sweden anna-clara.hollander@ki.se.
authors.forename: Anna-Clara
authors.initials: AC
authors.lastname: Hollander
authors.affiliation: Centre for Epidemiology and Community Medicine, Stockholm County Council, SE-171 77 Stockholm, Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Dal
authors.affiliation: Division of Psychiatry, University College London, London W1T 7NF, UK.
authors.forename: Glyn
authors.initials: G
authors.lastname: Lewis
authors.affiliation: Department of Public Health Sciences, Karolinska Institutet, 171 77 Stockholm, Sweden Centre for Epidemiology and Community Medicine, Stockholm County Council, SE-171 77 Stockholm, Sweden.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Magnusson
authors.affiliation: Division of Psychiatry, University College London, London W1T 7NF, UK.
authors.forename: James B
authors.initials: JB
authors.lastname: Kirkbride
authors.affiliation: Department of Public Health Sciences, Karolinska Institutet, 171 77 Stockholm, Sweden Centre for Epidemiology and Community Medicine, Stockholm County Council, SE-171 77 Stockholm, Sweden.
authors.forename: Christina
authors.initials: C
authors.lastname: Dalman
mesh_terms: D000293:Adolescent; D000328:Adult; D017954:Africa South of the Sahara / Q000453:epidemiology; D017677:Age Distribution; D000368:Aged; D005061:Europe, Eastern / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011618:Psychotic Disorders / Q000453:epidemiology / Q000208:ethnology*; D012036:Refugees / Q000523:psychology* / Q000706:statistics & numerical data*; D012426:Russia / Q000453:epidemiology; D012559:Schizophrenia / Q000453:epidemiology / Q000208:ethnology*; D017678:Sex Distribution; D012959:Socioeconomic Factors; D013548:Sweden / Q000453:epidemiology; D014171:Transients and Migrants / Q000523:psychology* / Q000706:statistics & numerical data*