Welcome to the PsyLife group research page. On this page you will find out more about the research we undertake. We conduct epidemiological research to investigate whether social and environmental factors are causally related to experiencing mental health problems. The main focus of our research is on identifying, understanding and preventing the social and environmental determinants of psychosis.

In particular, we specialise in two main research problems. First, we are seeking to determine and remove the causes of inequalities in psychosis risk by ethnicity and migrant status, one of the grossest injustices in public mental health. Second, we are seeking to understand whether being born, brought up and living in certain social environments (for example more urban, or more deprived) is a causal risk factor for psychosis.  

To investigate these issues, we apply both traditional and causal inference methods in epidemiology to large, population-based observational datasets of mental health problems. 

Epidemiology is a quantitative, population-based science which involves comparing differences in the risk of experiencing a given outcome between people who are, and who are not, exposed to a given risk factor. It involves assessing whether the association could have arisen by chance, may be attributable to other factors, or may have arisen as a result of biases in the way in which the data were collected and analysed. Understanding whether an association between a risk factor (or exposure, or determinant) and an outcome (such as a mental health disorder).

Wherever possible, we ensure our research is translated into evidence to help policymakers, mental health service providers and clinicians to make better decisions about care for people with mental health problems. You can read more about one example, the PsyMaptic prediction tool, on these  pages, which is used by NICE and NHS England to plan Early Intervention in Psychosis [EIP] services in England according to our epidemiological models of need for care in different local populations.   

Click on a project below to find out more about our work

PsyLife - Understanding the social determinants of psychosis & other mental health problems over the life course

Duration: 2014-present

Setting: Various, including Swedish national register data, ALSPAC birth cohort (UK), and the National Longitudinal Study of Children & Youth (NLSCY, Canada)

Funders: Wellcome Trust & Royal Society, MHRUK

Conducted at: Division of Psychiatry, UCL

PI: Dr James B. Kirkbride

Partners: Prof Ian Colman (University of Ottawa); Prof Christina Dalman (Karolinska Institutet)

Aim: To delineate the burden and social and environmental determinants of psychosis & other mental health problems

Method: Various methodologies, including causal inference methods applied to longitudinal datasets of mental health problems. Methods include causal mediation analysis, genetically-informed modelling, multilevel survival analysis, and other multilevel models.

Main findings: In ALSPAC, we demonstrated that the association between greater neighbourhood deprivation at birth and psychotic symptoms in adolescence was not explained by polygenic risk for schizophrenia [13]. We have also shown that children who live in neighbourhoods with higher levels of perceived neighbourhood stress and discord were more likely to report psychotic experiences during adolescence [12].

In nationwide Swedish data, we used causal mediation analysis to show that up to a quarter of the association between urban birth and later risk of psychotic disorder could be attributed to effects on cognition, if causal [10].

In other Swedish register studies, we have shown increased risk of mental health problems amongst migrants and their children appear specific to psychotic rather than affective domains of neuropsychopathology [3], and are influenced by family [2] and neighbourhood [1] social support during and after migration. Moving house more often and over longer distances in childhood and adolescence (but not adulthood) also predicts increased future risk of psychotic disorder [11].

We were the first group to conclusively demonstrate that refugees were more likely to experience psychosis than Swedish-born individuals and non-refugee migrants from the same regions [7]. We have shown elevated risks in refugee and other migrant groups do not exist for suicide [6] or substance use disorders [4], but rates of these mental health problems converge to Swedish rates over time. Migrants also experience more adverse pathways to psychiatric care [5,14].

Using Canadian data, we have also shown that children growing up in more adverse neighbourhoods are more likely to report mental health difficulties in adolescence [8]. However, we have also shown that growing up in positive environments, with high levels of social capital, can protect children against mental health problems in adolescence following exposure to stressful life events [9].

Impact: Results have furthered our understanding of the social aetiology of psychotic disorders, and could aid population-level prevention strategies for improving mental health in different communities.

Selected publications

1.
Dykxhoorn J, Lewis G, Hollander AC, Kirkbride JB, Dalman C. Association of neighbourhood migrant density and risk of non-affective psychosis: a national, longitudinal cohort study. The Lancet Psychiatry. 2020;7(4):327–336. http://doi.org/10.1016/S2215-0366(20)30059-6
1.
Dykxhoorn J, Hollander AC, Lewis G, Dalman C, Kirkbride JB. Family networks during migration and risk of non-affective psychosis: A population-based cohort study. Schizophrenia Research. 2019;208:268–275. http://doi.org/10.1016/j.schres.2019.01.044
1.
Dykxhoorn J, Hollander AC, Lewis G, Magnusson C, Dalman C, Kirkbride JB. Risk of schizophrenia, schizoaffective, and bipolar disorders by migrant status, region of origin, and age-at-migration: A national cohort study of 1.8 million people. Psychological Medicine. 2018;49(14):2354–2363. http://doi.org/10.1017/S0033291718003227
1.
Harris S, Dykxhoorn J, Hollander A-C, Dalman C, Kirkbride JB. Substance use disorders in refugee and migrant groups in Sweden: A nationwide cohort study of 1.2 million people. Alegria M, ed. PLOS Medicine. 2019;16(11):e1002944. http://doi.org/10.1371/journal.pmed.1002944
1.
Hollander A-C, Mackay E, Sjöqvist H, Kirkbride JB, Bäärnhielm S, Dalman C. Psychiatric care use among migrants to Sweden compared with Swedish-born residents: a longitudinal cohort study of 5 150 753 people. BMJ Global Health. 2020;5(9):e002471. http://doi.org/10.1136/bmjgh-2020-002471
1.
Hollander A-C, Pitman A, Sjöqvist H, et al. Suicide risk among refugees compared with non-refugee migrants and the Swedish-born majority population. The British Journal of Psychiatry. Published online October 2019:1–7. http://doi.org/10.1192/bjp.2019.220
1.
Hollander A-C, Dal H, Lewis G, Magnusson C, Kirkbride JB, Dalman C. Refugee migration and risk of schizophrenia and other non-affective psychoses: cohort study of 1.3 million people in Sweden. BMJ. 2016;352:i1030. http://doi.org/10.1136/bmj.i1030
1.
Kingsbury M, Kirkbride JB, McMartin SE, Wickham ME, Weeks M, Colman I. Trajectories of childhood neighbourhood cohesion and adolescent mental health: evidence from a national Canadian cohort. Psychol Med. Published online July 14, 2015:1-10. http://doi.org/10.1017/S0033291715001245
1.
Kingsbury M, Clayborne Z, Colman I, Kirkbride JB. The protective effect of neighbourhood social cohesion on adolescent mental health following stressful life events. Psychological Medicine. 2020;50(8):1292–1299. http://doi.org/10.1017/S0033291719001235
1.
Lewis G, Dykxhoorn J, Karlsson H, et al. Assessment of the Role of IQ in Associations between Population Density and Deprivation and Nonaffective Psychosis. JAMA Psychiatry. 2020;77(7):729–736. http://doi.org/10.1001/jamapsychiatry.2020.0103
1.
Price C, Dalman C, Zammit S, Kirkbride JB. Association of Residential Mobility Over the Life Course With Nonaffective Psychosis in 1.4 Million Young People in Sweden. JAMA Psychiatry. 2018;75(11):1128-1136. http://doi.org/10.1001/jamapsychiatry.2018.2233
1.
Solmi F, Colman I, Weeks M, Lewis G, Kirkbride JB. Trajectories of Neighborhood Cohesion in Childhood, and Psychotic and Depressive Symptoms at Age 13 and 18 Years. Journal of the American Academy of Child & Adolescent Psychiatry. Published online 2017. http://doi.org/10.1016/j.jaac.2017.04.003
1.
Solmi F, Lewis G, Zammit S, Kirkbride JB. Neighbourhood characteristics at birth and positive and negative psychotic symptoms in adolescence: fndings from the ALSPAC birth cohort. Schizophrenia Bulletin. 2020;46(3):581–591. http://doi.org/10.1093/schbul/sbz024
1.
Terhune J, Dykxhoorn J, Mackay E, Hollander A-C, Kirkbride JB, Dalman C. Migrant status and risk of compulsory admission at first diagnosis of psychotic disorder: a population-based cohort study in Sweden. Psychological Medicine. Published online June 2020:1–10. http://doi.org/10.1017/S0033291720002068

PsyMaptic-A - Psychiatric Mapping Translated into Innovations for Care

Duration: 2017-2020

Setting: England

Official website: www.psymaptic.org

Funders: Wellcome Trust & Royal Society

Conducted at: UCL, University of Cambridge, Hull-York Medical School, Manchester Metropolitan University

PI: Dr James B. Kirkbride

Co-Is: Profs Peter B. Jones, Gianluca Biao, Paul French, David Osborn, Jeremy Coid; Dr Pia Wohland

Aim: To develop a population-level prediction tool to predict need for Early Intervention in Psychosis [EIP] care in England up to 2025, using epidemiological data on first episode psychosis [FEP].

Method: Seed data from almost 1,500 people with FEP in England were used to estimate robust risks for disorder in the English population. These were combined with prior empirical information and projections of the future population in England in Bayesian Poisson regression models to forecast need in local populations (electoral ward level) up to 2025.  

Main findings: We developed and validated a population-level prediction tool to forecast the number of people in England requiring care for FEP each year up to 2025. We additionally forecast extra demand placed on EIP services resulting from additional referrals, assessments and treated cases who would not fulfil criteria for FEP. 

Impact: Since 2012 our free, open access predictions of likely need for EIP care in England have been used by NHS England to inform service planning. Our prediction tool, PsyMaptic, has informed and is recommend in NICE guidelines for commissioning and providing EIP services in England.  

Publications

1.
Kirkbride JB, Coid JW, Morgan C, et al. Translating the epidemiology of psychosis into public mental health: evidence, challenges and future prospects. Journal of Public Mental Health. 2010;9(2):4-14. http://www.ncbi.nlm.nih.gov/pubmed/21160544
1.
Kirkbride JB, Jackson D, Perez J, et al. A population-level prediction tool for the incidence of first-episode psychosis: translational epidemiology based on cross-sectional data. BMJ Open. 2013;3(2). http://doi.org/10.1136/bmjopen-2012-001998
1.
Kirkbride JB, Jones PB. Parity of esteem begins at home: translating empirical psychiatric research into effective public mental health. Psychological Medicine. 2014;44(8):1569-1576. http://doi.org/10.1017/S0033291713001992
1.
Kirkbride JB. Epidemiology on demand: population-based approaches to mental health service commissioning. BJPsych Bull. 2015;39(5):242-247. http://doi.org/10.1192/pb.bp.114.047746
1.
McDonald K, Ding T, Ker H, et al. Using epidemiological evidence to forecast population need for early treatment programmes in mental health: a generalisable Bayesian prediction methodology applied to and validated for first-episode psychosis in England. British Journal of Psychiatry. 2021;219(1):383-391. http://doi.org/10.1192/bjp.2021.18

SEPEA - The Social Epidemiology of Psychoses in East Anglia

Duration: 2009-2013

Setting: East Anglia, UK

Funder: Wellcome Trust

Conducted at: Department of Psychiatry, University of Cambridge

PI: Dr James B. Kirkbride; Co-I: Prof Peter B. Jones

Aim: To precisely estimate the treated incidence of psychotic disorders in a rural setting & investigate variation by social determinants for the first time.

Method: Naturalistic cohort study of all people aged 16-35 years old presenting to Early Intervention Psychosis [EIP] services in the region for the first time. Denominator obtained from 2011 Census. Basic sociodemographic & clinical data collected at baseline and discharge. Analyses included multilevel Poisson regression.

Main findings: Incidence of psychotic disorders higher than previously expected in rural region (Kirkbride et al, 2017, Am J Psych), but varied by age (highest risk in late adolescence/early 20s), sex (higher in men) and ethnicity (higher in several ethnic minority groups). Immigration during adolescence associated with higher risk (Kirkbride et al, 2017, Schiz Bull). More deprived, socially isolated rural areas had higher rates (Richardson et al, 2018, JAMA Psychiatry).

Impact: Results have furthered our understanding of the epidemiological landscape of psychotic disorders, showing substantial need for care in diverse, rural populations. Data have been used to inform future planning of EIP services in England as part of the PsyMaptic study.

Publications

1.
Ban K-Y, Osborn DPJ, Hameed Y, et al. Personality disorder in an Early Intervention Psychosis cohort: Findings from the Social Epidemiology of Psychoses in East Anglia (SEPEA) study. Guloksuz S, ed. PLOS ONE. 2020;15(6):e0234047. http://doi.org/10.1371/journal.pone.0234047
1.
Solmi F, Mohammadi A, Perez JA, Hameed Y, Jones PB, Kirkbride JB. Predictors of disengagement from Early Intervention in Psychosis services. Br J Psychiatry. 2018;213(2):477-483. http://doi.org/10.1192/bjp.2018.91
1.
Richardson L, Hameed Y, Perez J, Jones PB, Kirkbride JB. Association of Environment With the Risk of Developing Psychotic Disorders in Rural Populations: Findings from the Social Epidemiology of Psychoses in East Anglia Study. JAMA Psychiatry. 2018;75(1):75-83. http://doi.org/10.1001/jamapsychiatry.2017.3582
1.
Kirkbride JB, Hameed Y, Ioannidis K, et al. Ethnic Minority Status, Age-at-Immigration and Psychosis Risk in Rural Environments: Evidence From the SEPEA Study. Schizophr Bull. 2017;43(6):1251-1261. http://doi.org/10.1093/schbul/sbx010
1.
Kirkbride JB, Hameed Y, Wright L, et al. Waiting time variation in Early Intervention Psychosis services: longitudinal evidence from the SEPEA naturalistic cohort study. Soc Psychiatry Psychiatr Epidemiol. 2017;52(5):563-574. http://doi.org/10.1007/s00127-017-1343-7
1.
Kirkbride JB, Hameed Y, Ankireddypalli G, et al. The Epidemiology of First-Episode Psychosis in Early Intervention in Psychosis Services: Findings From the Social Epidemiology of Psychoses in East Anglia [SEPEA] Study. Am J Psychiatry. 2017;174(2):143-153. http://doi.org/10.1176/appi.ajp.2016.16010103
1.
Kirkbride JB, Stochl J, Zimbrón J, et al. Social and spatial heterogeneity in psychosis proneness in a multilevel case-prodrome-control study. Acta Psychiatr Scand. Published online December 31, 2014. http://doi.org/10.1111/acps.12384
1.
Kirkbride JB, Stubbins C, Jones PB. Psychosis incidence through the prism of early intervention services. The British Journal of Psychiatry. 2011;200(2):156-157. http://doi.org/10.1192/bjp.bp.111.094896

EU-GEI - The European Union Gene-Environment Interaction study

Duration: 2010-2014

Setting: 6 countries, 17-centres (WP2) including Cambridgeshire (UK)

Official website: www.eu-gei.eu

Funder: EU Framework Programme 7

Conducted at: Department of Psychiatry, University of Cambridge

Co-PI: Dr James B. Kirkbride; Co-PI: Prof Peter B. Jones

Aim: To understand the roles of genetic and environmental factors in contributing to the risk of experiencing psychotic disorders.

Method: Incidence and case-control study of ~2400 people in their first episode of psychosis, ~1200 of their unaffected siblings and ~2400 controls. We collected detailed biological, clinical and social data on our participants, and analyse the data in a variety of ways including multilevel Poisson and logistic regression.

Main findings: The first direct international comparison of incidence of psychotic disorders for over 30 years revealed considerable variation in rates between settings and countries [2]. We have shown that this is highly correlated with social determinants of health including economic disadvantage [2] and cannabis use [3]. Incidence rates are also raised in many ethnic minority groups. Using the case-control data from the study [4], we have also shown for the first time that exposure to structural racism (indexed via ethnically patterned social disadvantage, sociocultural exclusion and discrimination) can account for the excess risk of psychosis in several migrant and minority ethnic groups which have been consistently observed for over 140 years.

Impact: Findings from this study point towards new understanding of social and racial inequalities in psychosis risk, and provide a potential roadmap for public health practitioners to devise prevention strategies capable of removing these social injustices.

Publications

1.
Pignon B, Schürhoff F, Baudin G, et al. Spatial distribution of psychotic disorders in an urban area of France: an ecological study. Sci Rep. 2016;6:26190. http://doi.org/10.1038/srep26190
1.
Jongsma HE, Gayer-Anderson C, Lasalvia A, et al. Treated Incidence of Psychotic Disorders in the Multinational EU-GEI Study. JAMA Psychiatry. 2018;75(1):36. http://doi.org/10.1001/jamapsychiatry.2017.3554
1.
Di Forti M, Quattrone D, Freeman TP, et al. The contribution of cannabis use to variation in the incidence of psychotic disorder across Europe (EU-GEI): a multicentre case-control study. The Lancet Psychiatry. 2019;6(5):427–436. http://doi.org/10.1016/S2215-0366(19)30048-3
1.
Quattrone D, Di Forti M, Gayer-Anderson C, et al. Transdiagnostic dimensions of psychopathology at first episode psychosis: findings from the multinational EU-GEI study. Psychological Medicine. 2019;49(8):1378–1391. http://doi.org/10.1017/s0033291718002131
1.
Gayer-Anderson C, Jongsma HE, Di Forti M, et al. The EUropean Network of National Schizophrenia Networks Studying Gene–Environment Interactions (EU-GEI): Incidence and First-Episode Case–Control Programme. Social Psychiatry and Psychiatric Epidemiology. 2020;55(5):645–657. http://doi.org/10.1007/s00127-020-01831-x
1.
Jongsma HE, Gayer-Anderson C, Tarricone I, et al. Social disadvantage, linguistic distance, ethnic minority status and first-episode psychosis: Results from the EU-GEI case-control study. Psychological Medicine. Published online March 2020:1–13. http://doi.org/10.1017/S003329172000029X
1.
Ferraro L, La Cascia C, Quattrone D, et al. Premorbid Adjustment and IQ in Patients with First-Episode Psychosis: A Multisite Case-Control Study of Their Relationship with Cannabis Use. Schizophrenia Bulletin. 2020;46(3):517–529. http://doi.org/10.1093/schbul/sbz077
1.
Termorshuizen F, van der Ven E, Tarricone I, et al. The incidence of psychotic disorders among migrants and minority ethnic groups in Europe: findings from the multinational EU-GEI study. Psychological Medicine. Published online September 2020:1–10. http://doi.org/10.1017/S0033291720003219
1.
Tarricone I, D’Andrea G, Jongsma HE, et al. Migration history and risk of psychosis: results from the multinational EU-GEI study. Psychol Med. Published online 2021:1-13. http://doi.org/10.1017/S003329172000495X
1.
Tripoli G, Quattrone D, Ferraro L, et al. Jumping to conclusions, general intelligence, and psychosis liability: Findings from the multi-centre EU-GEI case-control study. Psychological Medicine. 2021;51(4):623-633. http://doi.org/10.1017/S003329171900357X
1.
Quattrone D, Ferraro L, Tripoli G, et al. Daily use of high-potency cannabis is associated with more positive symptoms in first-episode psychosis patients: The EU-GEI case-control study. Psychological Medicine. 2021;51(8):1329-1337. http://doi.org/10.1017/S0033291720000082
1.
Berendsen S, Kapitein P, Schirmbeck F, et al. Pre-training inter-rater reliability of clinical instruments in an international psychosis research project. Schizophrenia Research. 2021;230:104-107. http://doi.org/10.1016/j.schres.2020.08.001
1.
Velthorst E, Mollon J, Murray RM, et al. Cognitive functioning throughout adulthood and illness stages in individuals with psychotic disorders and their unaffected siblings. Mol Psychiatry. 2021;10(2):1-15. http://doi.org/10.1038/s41380-020-00969-z
1.
Misra S, Gelaye B, Williams DR, et al. Perceived major experiences of discrimination, ethnic group, and risk of psychosis in a six-country case-control study. Psychol Med. Published online March 2, 2021:1-9. http://doi.org/10.1017/S0033291721000453
1.
Ajnakina O, Rodriguez V, Quattrone D, et al. Duration of Untreated Psychosis in First-Episode Psychosis is not Associated With Common Genetic Variants for Major Psychiatric Conditions: Results From the Multi-Center EU-GEI Study. Schizophrenia Bulletin. Published online May 8, 2021:sbab055. http://doi.org/10.1093/schbul/sbab055
1.
Pignon B, Lajnef M, Kirkbride JB, et al. The Independent Effects of Psychosocial Stressors on Subclinical Psychosis: Findings From the Multinational EU-GEI Study. Schizophrenia Bulletin. Published online May 19, 2021:sbab060. http://doi.org/10.1093/schbul/sbab060

OLA - Building resilience and resources to overcome depression and anxiety in young people from urban neighbourhoods in Latin America

Duration: 2018-2023

Setting: Peru, Colombia, Argentina

Twitter: OLA study

Funder: MRC (UK)

Conducted at: Queen Mary University London, UCL, Peruvian University Cayetano Heredia, University of Buenos Aires, Pontifical University Javeriana, Kings College London

PI: Prof Stefan Priebe (QMUL); Co-I: Dr James B. Kirkbride

Aim: To understand the factors that contribute to resilience against depression in Latin American youth.

Method: Mixed methods study including cross-sectional and cohort survey of adolescent youth living in deprived parts of Lima (Peru), Bogota (Colombia), Buenos Aires (Argentina). 

Main findings: The study is currently underway and results are expected to be published over the next few years. Check our Twitter feed for latest news. 

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Systematic reviews

Duration: 2008-present

Setting & funders: Various

PI: Dr James B. Kirkbride

Aims: We conduct systematic reviews relevant to the incidence, prevalence and social and economic determinants of psychosis and other mental health conditions.

Method: We have an established systematic review methodology, and provide training to our MSc and PhD students with the skills and knowledge they need to conduct high quality reviews. Our reviews are pre-registered on PROSPERO and conform to Prisma guidelines. Where suitable, we also perform meta-analysis and meta-regression.

Main findings: In 2012 we published a highly-cited review of the incidence of psychotic disorders in England between 1950-2009 [2], showing robust variance in rates by person and place. This has been followed by an updated and influential review of the international incidence of psychotic disorders up to 2019 [6], and a separate review of the incidence of very-late onset schizophrenia-like psychosis [5]. We have also been involved in a review of the role of air pollution in mental health, finding robust associations between PM2.5 and depression and – potentially – anxiety [7]. We have also reviewed the literature between psychosis risk and place [1].

Impact: Our systematic review findings contribute to the consolidation of knowledge within the field. They have also been used to help guide empirical development of our population-level prediction tool for psychosis, PsyMaptic.

Publications

1.
March D, Hatch SL, Morgan C, et al. Psychosis and Place. Epidemiol Rev. 2008;30(1):84-100. http://doi.org/10.1093/epirev/mxn006
1.
Kirkbride JB, Errazuriz A, Croudace TJ, et al. Incidence of Schizophrenia and Other Psychoses in England, 1950–2009: A Systematic Review and Meta-Analyses. PLoS One. 2012;7(3):e31660. http://doi.org/10.1371/journal.pone.0031660
1.
Jackson D, Kirkbride J, Croudace T, et al. Meta-analytic approaches to determine gender differences in the age-incidence characteristics of schizophrenia and related psychoses. International Journal of Methods in Psychiatric Research. Published online 2013:n/a-n/a. http://doi.org/10.1002/mpr.1376
1.
Tortelli A, Errazuriz A, Croudace T, et al. Schizophrenia and other psychotic disorders in Caribbean-born migrants and their descendants in England: systematic review and meta-analysis of incidence rates, 1950-2013. Soc Psychiatry Psychiatr Epidemiol. Published online February 7, 2015. http://doi.org/10.1007/s00127-015-1021-6
1.
Stafford J, Howard R, Kirkbride JB. The incidence of very late-onset psychotic disorders: a systematic review and meta-analysis, 1960-2016. Psychol Med. 2018;48(11):1775-1786. http://doi.org/10.1017/S0033291717003452
1.
Jongsma HE, Turner C, Kirkbride JB, Jones PB. International incidence of psychotic disorders, 2002–17: a systematic review and meta-analysis. The Lancet Public Health. 2019;4(5):e229–e244. http://doi.org/10.1016/S2468-2667(19)30056-8
1.
Braithwaite I, Zhang S, Kirkbride JB, Osborn DPJ, Hayes JF. Air Pollution (Particulate Matter) Exposure and Associations with Depression, Anxiety, Bipolar, Psychosis and Suicide Risk: A Systematic Review and Meta-Analysis. Environmental Health Perspectives. 2019;127(12):126002. http://doi.org/10.1289/EHP4595
1.
Solmi M, Radua J, Olivola M, et al. Age at onset of mental disorders worldwide: large-scale meta-analysis of 192 epidemiological studies. Mol Psychiatry. Published online June 2, 2021. http://doi.org/10.1038/s41380-021-01161-7

DEPICt - Delineating the Epidemiology of first episode Psychosis In Chile: a nationwide register study of 30,000 incidenT cases between 2005 and 2018

Duration: 2019-20

Setting: Chile

Funder: UCL Grand Challenges of Global Health

Conducted at: UCL 

PI: Dr James B. Kirkbride; Co-I: Dr Christina Ding (UCL)

Partners: Dr Lucia Valmaggia (IoPPN), Dr Alfonso González-Valderrama (Universidad Finis Terrae), Dr Hannah Jongsma (UCL), Rayanne Jean-Baptiste Bastien

Aims: (1) To conduct a systematic review of the incidence of psychotic disorders in Global South countries. (2) To estimate the incidence of non-affective disorders in Chile using nationwide register data, and investigate variation by available social determinants of health. (3) To use this data to develop a version of the PsyMaptic prediction tool to estimate future need for psychosis care in Chile.

Method: Systematic review of the incidence of psychotic disorders in the Global South following PRISMA guidelines (Prospero ref: ). Incidence rates in Chile modelled from Chilean First-Episode of Schizophrenia Programme register, which records all people who presented to primary, secondary or tertiary care with a non-affective disorder between 2005-2018. Incidence modelled by multilevel Poisson regression with fractional polynomial regression terms fitted to inspect nonlinear associations with deprivation, time period and latitude. A version of the PsyMaptic tool followed a similar methodology to that described above.

Main findings: Incidence of non-affective disorders in Chile followed a typical age-sex distribution as observed in other studies [1]. Rates were higher in more deprived regions, but no association with population density was observed [1]. Incidence rates declined non-linearly, before increasing again over the time period, a trend which was more pronounced in women. No linear association with latitude was observed [1]

Impact: Our findings are informing psychosis care planning in Chile. The lack of association between population density and incidence rates of non-affective psychosis differ from many findings in Global North contexts, but should be examined more precisely in future studies.

Publications

1.
González-Valderrama A, Jongsma HE, Mena C, et al. The incidence of non-affective psychotic disorders in Chile between 2005 and 2018: results from a national register of over 30 000 cases. Psychological Medicine. Published online August 2020:1–10. http://doi.org/10.1017/S0033291720002664

PsyMap-Zn - PSYchosis MAPping in kwaZulu-Natal

Duration: 2019-2022

Setting: KwaZulu-Natal, South Africa

Funder: MRC (UK), SA-MRC (South Africa)

Conducted at: University of KwaZulu-Natal, University of Exeter, UCL, King’s College London, Stellenbosch University

PI: Profs Bonga Chiliza (KZN), Jonathan Burns (Exeter); Co-I: Dr James B. Kirkbride (UCL)

Aim: To estimate the incidence of psychotic disorders in a defined catchment area in KwaZulu-Natal, South Africa, and investigate the social determinants of any variation in risk.

Method: Incidence and case-control study working with traditional and formal healthcare providers to identify cases over a defined period of time. Multilevel Poisson regression analyses will be used to formally investigate variance in incidence.

Main findings: The study is currently underway and results are expected to be published over the next few years.

Meet the team

PsyMapZN study team

Other - various research

Duration: 2005-present

Setting & funders: Various

Summary: We are involved in various other studies investigating the epidemiology and public health impact of mental disorders on different populations.

Our early research, conducted by Dr James Kirkbride as part of his PhD and postdoctoral career, used epidemiological data from the AESOP and East London First Episode Psychosis studies to precisely characterise variation in incidence of schizophrenia and other psychotic disorders. This work has shown that people from Black Caribbean, Black African and Pakistani and Bangladeshi ethnicities in particular experience rates of psychotic disorder that are 2-4 times higher than in the White British population, even after accounting for differences in age, sex and socioeconomic position. This research has also shown higher rates occur in more urban communities with higher levels of inequality and deprivation.

Recent research we collaborated on from Australia has also found inequalities in psychosis risk by migrant status and ethnicity, for the first time in this context. Migrants from North and Sub-Saharan Africa were 3-5 times more likely to experiencing psychosis than the Australian-born population, but rates for Asian migrants were 2-4 times lower than for the Australian-born group. 

In cross-sectional survey from China, we have also investigated the prevalence of psychotic symptoms, showing that people reporting several  psychotic symptoms were more likely to have been born in urban areas.

We’ve also worked on research studies which have used epidemiological methods to investigate important questions, which at first glance might appear to be light-hearted. For example, we investigated a long-held hypothesis that cat ownership could increase risk of psychosis, putatively because of the association between toxoplasmosis (which can be harboured in cat poo) and psychosis. We used longitudinal data from ALSPAC to refute this hypothesis, finding no association between cat ownership in childhood and psychotic experiences in adolescence. In other research, published in a BMJ Christmas Special, we designed a cohort study to show that top-grossing movies for children had higher levels of death, including murder, than a corresponding sample of movies for adults!

Selected publications

1.
Boyle A, Kirkbride J, Jones P. Record linkage of domestic assault victims between an emergency department and the police. Journal of Epidemiology & Community Health. 2005;59(10):909-910. http://doi.org/10.1136/jech.2004.028597
1.
Fearon P, Kirkbride JB, Morgan C, et al. Incidence of schizophrenia and other psychoses in ethnic minority groups: results from the MRC AESOP Study. Psychological Medicine. 2006;36(11):1541-1550. http://www.ncbi.nlm.nih.gov/pubmed/16938150
1.
Kirkbride JB, Fearon P, Morgan C, et al. Heterogeneity in Incidence Rates of Schizophrenia and Other Psychotic Syndromes: Findings From the 3-Center ÆSOP Study. Arch Gen Psychiatry. 2006;63(3):250-258. http://www.ncbi.nlm.nih.gov/pubmed/16520429
1.
Kirkbride JB, Morgan C, Fearon P, Dazzan P, Murray RM, Jones PB. Neighbourhood-level effects on psychoses: re-examining the role of context. Psychol Med. 2007;37(10):1413-1425. http://www.ncbi.nlm.nih.gov/pubmed/17472758
1.
Kirkbride JB, Fearon P, Morgan C, et al. Neighbourhood variation in the incidence of psychotic disorders in Southeast London. Social Psychiatry and Psychiatric Epidemiology. 2007;42(6):438-445. http://www.ncbi.nlm.nih.gov/pubmed/17473901
1.
Kirkbride JB, Barker D, Cowden F, et al. Psychoses, ethnicity and socio-economic status. British Journal of Psychiatry. 2008;193(1):18-24. http://www.ncbi.nlm.nih.gov/pubmed/18700213
1.
Coid JW, Kirkbride JB, Barker D, et al. Raised incidence rates of all psychoses among migrant groups: Findings from the east london first episode psychosis study. Archives of General Psychiatry. 2008;65(11):1250–1258. http://doi.org/10.1001/archpsyc.65.11.1250
1.
Colman I, Kingsbury M, Weeks M, et al. CARTOONS KILL: casualties in animated recreational theater in an objective observational new study of kids’ introduction to loss of life. BMJ. 2014;349:g7184.
1.
Kirkbride JB, Jones PB, Ullrich S, Coid JW. Social Deprivation, Inequality, and the Neighborhood-Level Incidence of Psychotic Syndromes in East London. Schizophrenia Bulletin. 2014;40(1):169-180. http://doi.org/10.1093/schbul/sbs151
1.
Morgan C, Reininghaus U, Fearon P, et al. Modelling the interplay between childhood and adult adversity in pathways to psychosis: initial evidence from the AESOP study. Psychological medicine. 2014;44(2):407-419. http://doi.org/10.1017/S0033291713000767
1.
Solmi F, Hayes JF, Lewis G, Kirkbride JB. 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 cohort. Psychol Med. Published online February 22, 2017:1-9. http://doi.org/10.1017/S0033291717000125
1.
Coid JW, Hu J, Kallis C, et al. Urban Birth, Urban Living, and Work Migrancy: Differential Effects on Psychotic Experiences Among Young Chinese Men. Schizophr Bull. Published online December 29, 2017. http://doi.org/10.1093/schbul/sbx152
1.
O’Donoghue B, Downey L, Eaton S, Mifsud N, Kirkbride JB, McGorry P. Risk of psychotic disorders in migrants to Australia. Psychological Medicine. 2021;51(7):1192-1200. http://doi.org/10.1017/S0033291719004100
1.
Baskin C, Zijlstra G, McGrath M, et al. Community-centred interventions for improving public mental health among adults from ethnic minority populations in the UK: a scoping review. BMJ Open. 2021;11(4):e041102. http://doi.org/10.1136/bmjopen-2020-041102
1.
McGrath M, Duncan F, Dotsikas K, et al. Effectiveness of community interventions for protecting and promoting the mental health of working-age adults experiencing financial uncertainty: a systematic review. J Epidemiol Community Health. 2021;75(7):665-673. http://doi.org/10.1136/jech-2020-215574
1.
Lee C, Kuhn I, McGrath M, et al. A systematic scoping review of community‐based interventions for the prevention of mental ill‐health and the promotion of mental health in older adults in the UK. Health Soc Care Community. Published online May 14, 2021:hsc.13413. http://doi.org/10.1111/hsc.13413