a1 NIHR Biomedical Research Centre, and Centre for Public Mental Health, Health Service and Population Research Department, Institute of Psychiatry, King's College, London, UK
a2 Department of Psychiatry, University of Cambridge, Cambridge, UK
a3 Psychiatry Unit, University of the West Indies, Trinidad
a4 NIHR Biomedical Research Centre, and Division of Psychological Medicine, Institute of Psychiatry, King's College, London, UK
a5 Department of Psychology, Westminster University, London, UK
a6 Division of Psychiatry, University of Nottingham, Nottingham, UK
Background Numerous studies have reported high rates of psychosis in the Black Caribbean population in the UK. Recent speculation about the reasons for these high rates has focused on social factors. However, there have been few empirical studies. We sought to compare the prevalence of specific indicators of social disadvantage and isolation, and variations by ethnicity, in subjects with a first episode of psychosis and a series of healthy controls.
Method All cases with a first episode of psychosis who made contact with psychiatric services in defined catchment areas in London and Nottingham, UK and a series of community controls were recruited over a 3-year period. Data relating to clinical and social variables were collected from cases and controls.
Results On all indicators, cases were more socially disadvantaged and isolated than controls, after controlling for potential confounders. These associations held when the sample was restricted to those with an affective diagnosis and to those with a short prodrome and short duration of untreated psychosis. There was a clear linear relationship between concentrated disadvantage and odds of psychosis. Similar patterns were evident in the two main ethnic groups, White British and Black Caribbean. However, indicators of social disadvantage and isolation were more common in Black Caribbean subjects than White British subjects.
Conclusions We found strong associations between indicators of disadvantage and psychosis. If these variables index exposure to factors that increase risk of psychosis, their greater prevalence in the Black Caribbean population may contribute to the reported high rates of psychosis in this population.
(Received November 14 2007)
(Revised May 10 2008)
(Accepted May 12 2008)
c1 Address for correspondence: C. Morgan, Ph.D., Centre for Public Mental Health, Health Service and Population Research Department, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK. (Email: firstname.lastname@example.org)