James B Kirkbride

Psychoses, ethnicity and socio-economic status.

BACKGROUNDnConsistent observation of raised rates of psychoses among Black and minority ethnic (BME) groups may possibly be explained by their lower socio-economic status.nnnAIMSnTo test whether risk for psychoses remained elevated in BME populations compared with the White British, after adjustment for age, gender and current socio-economic status.nnnMETHODnPopulation-based study of first-episode DSM-IV psychotic disorders, in individuals aged 18-64 years, in East London over 2 years.nnnRESULTSnAll BME groups had elevated rates of a psychotic disorder after adjustment for age, gender and socio-economic status. For schizophrenia, risk was elevated for people of Black Caribbean (incidence rate ratios (IRR)=3.1, 95% CI 2.1-4.5) and Black African (IRR=2.6, 95% CI 1.8-3.8) origin, and for Pakistani (IRR=3.1, 95% CI 1.2-8.1) and Bangladeshi (IRR=2.3, 95% CI 1.1-4.7) women. Mixed White and Black Caribbean (IRR=7.7, 95% CI 3.2-18.8) and White Other (IRR=2.1, 95% CI 1.2-3.8) groups had elevated rates of affective psychoses (and other non-affective psychoses).nnnCONCLUSIONSnElevated rates of psychoses in BME groups could not be explained by socio-economic status, even though current socio-economic status may have overestimated the effect of this confounder given potential misclassification as a result of downward social drift in the prodromal phase of psychosis. Our findings extended to all BME groups and psychotic disorders, though heterogeneity remains.

Prenatal nutrition, epigenetics and schizophrenia risk: can we test causal effects?

We posit that maternal prenatal nutrition can influence offspring schizophrenia risk via epigenetic effects. In this article, we consider evidence that prenatal nutrition is linked to epigenetic outcomes in offspring and schizophrenia in offspring, and that schizophrenia is associated with epigenetic changes. We focus upon one-carbon metabolism as a mediator of the pathway between perturbed prenatal nutrition and the subsequent risk of schizophrenia. Although post-mortem human studies demonstrate DNA methylation changes in brains of people with schizophrenia, such studies cannot establish causality. We suggest a testable hypothesis that utilizes a novel two-step Mendelian randomization approach, to test the component parts of the proposed causal pathway leading from prenatal nutritional exposure to schizophrenia. Applied here to a specific example, such an approach is applicable for wider use to strengthen causal inference of the mediating role of epigenetic factors linking exposures to health outcomes in population-based studies.

The Prevention of Schizophrenia—What Can We Learn From Eco-Epidemiology?

The search for the causes of schizophrenia has predominantly originated from 2 research paradigms; genetics and epidemiology. While each approach has made important contributions to etiological understanding, neither has fully resolved the exact milieu of risk factors for schizophrenia, and there is growing recognition that several pathways to the onset of such disorders may exist. Eco-epidemiology offers an integrative framework to study schizophrenia etiology, incorporating multiple, interactive levels of causation, including genetic, epigenetic, individual, familial, community, and societal domains over the life course. In this article, we review the current evidence base, through the lens of eco-epidemiology, to determine whether it warrants the design and implementation of putative prevention strategies for schizophrenia. We argue that while there are potentially large public health gains available, we do not currently have sufficient empirical data to design effective prevention strategies. It will be important for the research community to more fully elucidate the likely multifactorial, multilevel, polygenetic, and eco-epidemiological basis of schizophrenia before we can design useful prevention strategies. We conclude by speculating on the forms effective strategies might take.

Psychosis incidence through the prism of early intervention services

We know little about first-episode psychosis epidemiology beyond cities or when measured through early intervention in psychosis services. We present results from 18 months of the 3-year Social Epidemiology of Psychoses in East Anglia (SEPEA) study of incepted incidence observed through five early intervention services. We identified 378 eligible individuals (incidence: 45.1/100 000 person-years, 95% CI 40.8–49.9). Rates varied across these services, but were 2–3 times higher than those on which services were commissioned. Risk decreased with age, was nearly doubled among men and differed by ethnic group; doubled in people of mixed ethnicity but lower for those of Asian origin, compared with White British people. Psychosis risk among ethnic minorities was lower than reported in urban settings, which has potential implications for aetiology. Our data suggest considerable psychosis morbidity in diverse, rural communities.

Migration and Mental Health: Epidemiological aspects of migration and mental illness

This volume explores all aspects of migration, on all scales, and its effect on mental health. It covers migration in the widest sense and does not limit itself to refugee studies.