Department of Health Services and Population Research, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK
Helen A. Weiss
MRC International Statistics and Epidemiology Group, London School of Hygiene & Tropical Medicine, UK
Sujit John
Department of Psychiatry, Schizophrenia Research Foundation, India
Oluyomi Esan
Department of Psychiatry, University of Ibadan, Nigeria
Maia Hibben
Department of Psychiatry, Faculty of Medical Sciences, University of the West Indies, Trinidad and Tobago
Vikram Patel
Department of Global Health and Social Medicine, Harvard Medical School, Massachusetts, USA; and Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Harvard University, Massachusetts, USA
Robin M. Murray
Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK
Centre for Global Mental Health, London School of Hygiene & Tropical Medicine, UK
Gerard Hutchinson
Department of Psychiatry, Faculty of Medical Sciences, University of the West Indies, Trinidad and Tobago
Oye Gureje
WHO Collaborating Centre for Research and Training in Mental Health, Neuroscience and Substance Abuse, Department of Psychiatry, University of Ibadan, Nigeria
Rangaswamy Thara
Department of Psychiatry, Schizophrenia Research Foundation, India
Background There is evidence of an association between life events and psychosis in Europe, North America and Australasia, but few studies have examined this association in the rest of the world. Aims To test the association between exposure to life events and psychosis in catchment areas in India, Nigeria, and Trinidad and Tobago. Method We conducted a population-based, matched case–control study of 194 participants in India, Nigeria, and Trinidad and Tobago. Cases were recruited through comprehensive population-based, case-finding strategies. The Harvard Trauma Questionnaire was used to measure life events. The Screening Schedule for Psychosis was used to screen for psychotic symptoms. The association between psychosis and having experienced life events (experienced or witnessed) was estimated by conditional logistic regression. Results There was no overall evidence of an association between psychosis and having experienced or witnessed life events (adjusted odds ratio 1.19, 95% CI 0.62–2.28). We found evidence of effect modification by site (P = 0.002), with stronger evidence of an association in India (adjusted odds ratio 1.56, 95% CI 1.03–2.34), inconclusive evidence in Nigeria (adjusted odds ratio 1.17, 95% CI 0.95–1.45) and evidence of an inverse association in Trinidad and Tobago (adjusted odds ratio 0.66, 95% CI 0.44–0.97). Conclusions This study found no overall evidence of an association between witnessing or experiencing life events and psychotic disorder across three culturally and economically diverse countries. There was preliminary evidence that the association varies between settings.
