Ethnic density, urbanicity and psychosis risk for migrant groups - A population cohort study.
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.



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.



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).



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.
Division of Health & Social Care Research, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom. Electronic address: peter.1.schofield@kcl.ac.uk.
Peter
P
Schofield
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.
Malene
M
Thygesen
Health Service & Population Research Department, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom.
Jay
J
Das-Munshi
Centre on Dynamics of Ethnicity, The University of Manchester, Manchester, United Kingdom.
Laia
L
Becares
Social Medicine and Global Health, Lund University, Lund, Sweden.
Elizabeth
E
Cantor-Graae
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.
Carsten
C
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
E
Agerbo
D015331:Cohort Studies; D018864:Cultural Diversity; D003718:Denmark; D005006:Ethnicity; D006801:Humans; D015994:Incidence; D011618:Psychotic Disorders / Q000453:epidemiology*; D012307:Risk Factors; D012424:Rural Population; D012959:Socioeconomic Factors; D014171:Transients and Migrants / Q000523:psychology; D014505:Urban Population
Ethnicity; Etiology; Psychosis; Social determinants