Psychoses sans Frontieres: towards an interdisciplinary understanding of psychosis risk amongst migrants and their descendants

Understanding the excess risk of psychotic disorders in migrant and ethnic minority groups has long been an important research focus in psychiatric epidemiology and public mental health. Heterogeneity between migrant groups based on the region of origin, minority status and other socioeconomic factors may provide clues as to the underlying aetiological mechanisms explaining this risk, as well as informing our general understanding of psychotic disorders. Nonetheless, disentangling the mechanisms underlying this association has been the focus of more speculation and theory to date than empirical research. Now more than ever, we need to move beyond studies which demonstrate excess rates in migrant and ethnic minority groups to novel population-based studies which identify the determinants and mechanisms through which this risk is shaped. In this paper, we review the main hypotheses proposed to explain these disparities and the current level of support for them. We then highlight recent evidence from epidemiology and neuroscience which provides important new clues in our understanding of the aetiology of psychotic disorders. We concluded with suggestions for future interdisciplinary research to prevent this public mental health inequality within a generation

Addressing ethnic inequalities in the pathways to care for psychosis

Delays in accessing appropriate care affect patients with most major health conditions, including psychosis. These delays may also be affected by pathways to care. In a recent article in BMC Medicine, Bhui and colleagues review the current evidence for ethnic differences in pathways to care for psychosis in England. They reveal that black and Asian people are 3 and 1.5 times more likely, respectively, to come to the attention of psychosis services via compulsory admission than white British people. In this Commentary, I discuss the implications of this on achieving equitable care for psychosis patients and outcomes following their care. The current review of the Mental Health Act provides a timely opportunity to remove such inequalities in England.Please see related article: https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-018-1201-9

The emerging molecular architecture of schizophrenia, polygenic risk scores and the clinical implications for gXe research.

In this commentary I review the recent paper by Iyegbe et al. on "The emerging molecular architecture of schizophrenia, polygenic risk scores and the clinical implications for gXe research". I discuss how the paper advances our knowledge of polygenic risk scores for use, amongst others, in gene-environment interaction studies and the opportunities and challenges such approaches will bring to our understanding of the epidemiology of psychotic disorders, including schizophrenia

Hitting the floor: Understanding migration patterns following the first episode of psychosis

Recent research published in Health and Place (Ngamini Ngui et al., 2013b) found that one third of people with first episode psychosis [FEP] will have made a large-scale migration six years after initial diagnosis. Here, I extend this discussion around three important observations. Namely, at first presentation the most disadvantaged communities already shoulder the burden of psychotic morbidity; people with FEP in more rural communities migrate less often, and; people with FEP exhibit both upwards and downwards social mobility after onset. Understanding the reasons for (non-)migration before and after psychosis onset is now required for effective public mental health and service provision

Curiosity killed the cat: no evidence of an association between cat ownership and psychotic symptoms at ages 13 and 18 years in a UK general population

Congenital or early life infection with Toxoplasma gondii has been implicated in schizophrenia aetiology. Childhood cat ownership has been hypothesized as an intermediary marker of T. gondii infection and, by proxy, as a risk factor for later psychosis. Evidence supporting this hypothesis is, however, limited. We used birth cohort data from the Avon Longitudinal Study of Parents and Children (ALSPAC) to investigate whether cat ownership in pregnancy and childhood (ages 4 and 10 years) was associated with psychotic experiences (PEs) in early (age 13, N = 6705) and late (age 18, N = 4676) adolescence, rated from semi-structured interviews. We used logistic regression to examine associations between cat ownership and PEs, adjusting for several sociodemographic and socioeconomic factors, household characteristics and dog ownership. Missing data were handled via multiple imputation. Cat ownership during pregnancy was not associated with PEs at age 13 years [adjusted odds ratio (OR) 1.15, 95% confidence interval (CI) 0.97–1.35] or 18 years (OR 1.08, 95% CI 0.86–1.35). Initial univariable evidence that cat ownership at ages 4 and 10 years was associated with PEs at age 13 years did not persist after multivariable adjustment (4 years: OR 1.18, 95% CI 0.94–1.48; 10 years: OR 1.12, 95% CI 0.92–1.36). There was no evidence that childhood cat ownership was associated with PEs at age 18 years. While pregnant women should continue to avoid handling soiled cat litter, given possible T. gondii exposure, our study strongly indicates that cat ownership in pregnancy or early childhood does not confer an increased risk of later adolescent PEs

Risk of non-affective psychotic disorder and post-traumatic stress disorder by refugee status in Sweden

BACKGROUND: Refugees have different experiences of obtaining a refugee status, however it remains unclear if this affects their risk of psychiatric disorders. The aim of this study was to investigate whether risk for non-affective psychotic disorder (NAPD) and post-traumatic stress disorder (PTSD) differs between quota refugees (resettled from refugee camps) and non-quota refugees (former asylum seekers). METHOD: A register-based cohort with a sample size of 52 561 refugees in Sweden starting 1 January 1997 ending 31 December 2011. EXPOSURE: refugee status (quota or non-quota refugees). Cox regression models estimated adjusted HRs with 95% CIs for NAPD (International Classification of Diseases, Tenth Revision (ICD-10), F20-29) and PTSD (ICD-10, F43.1) by refugee status. RESULTS: There were more non-quota refugees (77.0%) than quota refugees (23.0%). In total we identified 401 cases of NAPD, 1.0% among quota refugees and 0.7% among non-quota refugees, and 1070 cases of PTSD, 1.9% among quota refugees and 2.1% among non-quota refugees. Male quota refugees were at increased risk for NAPD compared with male non-quota refugees (HRmale=1.41, 95% CI 1.09 to 1.82 and HRfemale=0.65, 95% CI 0.42 to 1.00). All quota refugees were at a reduced risk of PTSD compared with non-quota refugees (HR=0.74, 95% CI 0.64 to 0.87). CONCLUSIONS: This study suggests that risk of NAPD and PTSD varies for quota and non-quota refugees, highlighting the possibility that different experiences of the migration process differentiate the risk of psychiatric disorders among refugees