Comparison of the incidence of schizophrenia in rural Dumfries and Galloway and urban Camberwell

Incidence, prevalence, and mortality of schizophrenia from 2016 to 2020 in Shandong, China

The epidemiology of schizophrenia has been reported in many countries. However, due to the limitations of those studies, the findings cannot be generalized to other parts of the world, especially in China. In this study, the incidence, prevalence, and mortality of schizophrenia in Shandong, China were calculated using data from the National Severe Mental Disorder Registration System collected between 2016 and 2020 and census data from 2010 to 2020. The overall incidence decreased from 9.61 per 100,000 in 2016 to 4.40 per 100,000 in 2020, the aggregate prevalence was approximately 3.20 per 1000, and the overall mortality ranged from 6.17 per 100,000 to 7.71 per 100,000. The evidence from this study indicated that the incidence, prevalence, and mortality of schizophrenia were higher in rural areas than in urban areas. Females had higher incidence, prevalence, and mortality than males. This study provided epidemiological information on schizophrenia and opened avenues for future research.

Review of Major Social Determinants of Health in Schizophrenia-Spectrum Disorders: II. Assessments

BACKGROUND AND AIMS

Social determinants of health (SDoHs) impact the development and course of schizophrenia-spectrum psychotic disorders (SSPDs). Yet, we found no published scholarly reviews of psychometric properties and pragmatic utility of SDoH assessments among people with SSPDs. We aim to review those aspects of SDoH assessments.

STUDY DESIGN

PsychInfo, PubMed, and Google Scholar databases were examined to obtain data on reliability, validity, administration process, strengths, and limitations of the measures for SDoHs identified in a paired scoping review.

STUDY RESULTS

SDoHs were assessed using different approaches including self-reports, interviews, rating scales, and review of public databases. Of the major SDoHs, early-life adversities, social disconnection, racism, social fragmentation, and food insecurity had measures with satisfactory psychometric properties. Internal consistency reliabilities-evaluated in the general population for 13 measures of early-life adversities, social disconnection, racism, social fragmentation, and food insecurity-ranged from poor to excellent (0.68-0.96). The number of items varied from 1 to more than 100 and administration time ranged from less than 5 minutes to over an hour. Measures of urbanicity, low socioeconomic status, immigration status, homelessness/housing instability, and incarceration were based on public records or targeted sampling.

CONCLUSIONS

Although the reported assessments of SDoHs show promise, there is a need to develop and test brief but validated screening measures suitable for clinical application. Novel assessment tools, including objective assessments at individual and community levels utilizing new technology, and sophisticated psychometric evaluations for reliability, validity, and sensitivity to change with effective interventions are recommended, and suggestions for training curricula are offered.

Associations between urban birth or childhood trauma and first-episode schizophrenia mediated by low IQ

Exposure to urban birth, childhood trauma, and lower Intelligence Quotient (IQ) were the most well-established risk factors for schizophrenia in developed countries. In developing countries, whether urban birth is a risk factor for schizophrenia and how these factors are related to one another remain unclear. This study aimed to investigate whether IQ mediates the relationship between urban birth or childhood trauma and first-episode schizophrenia (FES) in China. Birthplace, childhood trauma questionnaire (CTQ), and IQ were collected from 144 patients with FES and 256 healthy controls (HCs). Hierarchical logistic regression analysis was conducted to investigate the associations between birthplace, childhood trauma, IQ, and FES. Furthermore, mediation analysis was used to explore the mediation of IQ in the relationship between birthplace or childhood trauma and FES. After adjusting for age, sex and educational attainment, the final model identified urban birth (odds ratio (OR) = 3.15, 95% CI = 1.54, 6.44) and childhood trauma (OR = 2.79, 95% CI = 1.92, 4.06) were associated an elevated risk for FES. The 52.94% total effect of birthplace on the risk of FES could be offset by IQ (indirect effect/direct effect). The association between childhood trauma and FES could be partly explained by IQ (22.5%). In total, the mediation model explained 70.5% of the total variance in FES. Our study provides evidence that urban birth and childhood trauma are associated with an increased risk of FES. Furthermore, IQ mediates the relationship between urban birth or childhood trauma and FES.

Stress and emotional arousal in urban environments: A biosocial study with persons having experienced a first-episode of psychosis and persons at risk

This article examines the entanglement between feelings of stress and discomfort, physiological arousal and urban experiences of persons living with early psychosis. It adopts a biosocial approach, using mixed methods combining ambulatory skin conductance monitoring, mobile interviews and contextual data, collected through GPS and video recordings. The study draws on and strives to cross-fertilize two recent strands of research. The first relates to the use of digital phenotyping in mental health research. The second explores stress and emotional arousal in cities using ambulatory physiological measures. Empirically, the paper is based on fieldwork in Basel, Switzerland, with nine participants recruited within the Basel Early Treatment Service (BEATS), and four controls. We focus on three salient elements in our results: visual perception of moving bodies, spatial transitions and openness and enclosure of the built environment. The analysis shows how these elements elicit physiological responses of arousal and expressed feelings of discomfort. In the concluding section we discuss the methodological implications of these results and suggest the notion of regime of attention as a focus for future biosocial research on urban mental health.

Gender differences in the association between environment and psychosis

Various environmental exposures have been associated with psychosis spectrum disorder. However, the role of gender in this association has received little attention. Therefore, we conducted a systematic review to evaluate gender-related differences and identified 47 research articles investigating the associations of psychosis with childhood adversity, substance use, urbanicity, migration, season of birth, and obstetric complication in the PubMed database. The findings suggest that childhood abuse may be more strongly associated with a risk to develop psychosis and an earlier age at onset of illness in women than in men. Furthermore, childhood adversity has been associated with the severity of different symptom dimensions in men and women. Growing up in an urban environment and immigration are more strongly associated with psychosis risk in men than in women. Despite a higher prevalence of substance abuse comorbidity in men diagnosed with psychotic disorders, it appears that the association between substance use and psychosis risk may be stronger in women. These findings should be evaluated with caution considering several methodological limitations, limited number of studies, and lack of consistency across results. Overall, although further investigation is needed, our review shows that gender-related differences in the associations of environmental exposures with psychosis expression may exist.

Explaining the Association Between Urbanicity and Psychotic-Like Experiences in Pre-Adolescence: The Indirect Effect of Urban Exposures

Urban living is a growing worldwide phenomenon with more than two-thirds of people expected to live in cities by 2050. Although there are many benefits to living in an urban environment, urbanicity has also been associated with deleterious health outcomes, including increased risk for psychotic outcomes particularly when the urban exposure occurs in pre-adolescence. However, the mechanisms underlying this association is unclear. Here, we utilize one-year follow-up data from a large (N=7,979), nationwide study of pre-adolescence in the United States to clarify why urbanicity (i.e., census-tract population density) might impact psychotic-like experiences (PLE) by looking at the indirect effect of eight candidate urbanicity-related physical (e.g., pollution) and social (e.g., poverty) exposures. Consistent with other work, we found that of the evaluated exposures related to urbanicity, several were also related to increased number of PLE: PM2.5, proximity to roads, census-level homes at-risk for exposure to lead paint, census-level poverty, and census-level income-disparity. These same urban-related exposures were also related to the persistence of PLE after 1 year, but not new onset of PLE. Mediation analysis revealed that a substantial proportion the urbanicity-PLE association (number and persistence) could be explained by PM2.5 (23-44%), families in poverty (68-93%), and income disparity (67-80%). Together, these findings suggest that specific urban-related exposures contribute to the existence and maintenance, but not onset of PLE, which might help to explain why those in urban environments are disproportionately at-risk for psychosis and point toward areas for public health intervention.

Urban-Rural Differences in Schizophrenia Risk: Multilevel Survival Analyses of Individual- and Neighborhood-Level Indicators, Urbanicity and Population Density in a Danish National Cohort Study

Background

Urban-rural differences in schizophrenia risk have been widely evidenced across Western countries. However, explanation of these differences is lacking. We aimed to identify contextual risk factors for schizophrenia that explain urban-rural differences in schizophrenia risk.

Methods

Utilizing Danish population-based registers, we partitioned Denmark into 1885 geographic "neighborhoods" homogeneously sized in terms of population. Information on the entire Danish population from 1981 to 2016 was used to quantify a spectrum of neighborhood-level domains. We subsequently conducted multilevel survival analyses following persons born in Denmark from 1971 to 1982 for the development of schizophrenia allowing for clustering of people within neighborhoods. We used this method to tease apart the effects of individual, specific, and general contextual risk factors for schizophrenia.

Results

A significant general contextual effect in schizophrenia risk across neighborhoods was estimated (Medium Incidence Rate Ratio (MRR):1.41; 95% CI:1.35-1.48). Most of the specific contextual factors examined were associated with schizophrenia risk. For instance, neighborhood-level proportion of lone adult households (Incidence Rate Ratios (IRR):1.53; 95% CI:1.44-1.63) had largest risk estimate. Adjustment for all individual-level and specific contextual constructs reduced the IRR for urbanicity from 1.98 (95% CI:1.77-2.22) to 1.30 (95% CI:1.11-1.51).

Conclusions

In the largest prospective multilevel survival analyses of schizophrenia risk conducted to date, multiple neighborhood-level characteristics were associated with raised schizophrenia risk, with these contextual factors explaining most of the elevated risk linked with urbanicity. However, the unexplained heterogeneity that was evident in our multilevel models indicates that our understanding of the role of urbanicity in schizophrenia's etiology remains incomplete.

Urbanicity mental costs valuation: a review and urban-societal planning consideration

Living in cities has numerous comparative advantages than living in the countryside or in small villages and towns, most notably better access to education, services and jobs. However, it is also associated with a roughly twofold increase in some mental disorders rate incidence compared with living in rural areas. Economic assessments reported a forecasted loss of more than 19 trillion dollars in global GDP between 2011 and 2030 and of around 7 trillion for the year 2030 alone when measured by the human capital method. If we exclude self-selection processes and make the hypothesis to be able to level down the mental illness rate incidence in urban areas to these of the rural by better urban-societal planning, around € 1.2 trillion could be saved yearly worldwide. Even a reduction of only 20% in urban mental illness rate would save around 250 billion dollars yearly.

Urbanicity: The need for new avenues to explore the link between urban living and psychosis

AIM

A growing body of evidence suggests that urban living contributes to the development of psychosis. However, the mechanisms underlying this phenomenon remain unclear. This paper aims to explore the best available knowledge on the matter, identify research gaps and outline future prospects for research strategies.

METHOD

A comprehensive literature survey on the main computerized medical research databases, with a time limit up to August 2017 on the issue of urbanicity and psychosis has been conducted.

RESULTS

The impact of urbanicity may result from a wide range of factors (from urban material features to stressful impact of social life) leading to "urban stress." The latter may link urban upbringing to the development of psychosis through overlapping neuro- and socio-developmental pathways, possibly unified by dopaminergic hyperactivity in mesocorticolimbic system. However, "urban stress" is poorly defined and research based on patients' experience of the urban environment is scarce.

CONCLUSIONS

Despite accumulated data, the majority of studies conducted so far failed to explain how specific factors of urban environment combine in patients' daily life to create protective or disruptive milieus. This undermines the translation of a vast epidemiological knowledge into effective therapeutic and urbanistic developments. New studies on urbanicity should therefore be more interdisciplinary, bridging knowledge from different disciplines (psychiatry, epidemiology, human geography, urbanism, etc.) in order to enrich research methods, ensure the development of effective treatment and preventive strategies as well as create urban environments that will contribute to mental well-being.

Ethnic inequalities in the incidence of diagnosis of severe mental illness in England: a systematic review and new meta-analyses for non-affective and affective psychoses

PURPOSE

Although excess risks particularly for a diagnosis of schizophrenia have been identified for ethnic minority people in England and other contexts, we sought to identify and synthesise up-to-date evidence (2018) for affective in addition to non-affective psychoses by specific ethnic groups in England.

METHODS

Systematic review and meta-analysis of ethnic differences in diagnosed incidence of psychoses in England, searching nine databases for reviews (citing relevant studies up to 2009) and an updated search in three databases for studies between 2010 and 2018. Studies from both searches were combined in meta-analyses allowing coverage of more specific ethnic groups than previously.

RESULTS

We included 28 primary studies. Relative to the majority population, significantly higher risks of diagnosed schizophrenia were found in Black African (Relative risk, RR 5.72, 95% CI 3.87-8.46, n = 9); Black Caribbean (RR 5.20, 95% CI 4.33-6.24, n = 21); South Asian (RR 2.27, 95% CI 1.63-3.16, n = 14); White Other (RR 2.24, 95% CI 1.59-3.14, n = 9); and Mixed Ethnicity people (RR 2.24, 95% CI 1.32-3.80, n = 4). Significantly higher risks for diagnosed affective psychoses were also revealed: Black African (RR 4.07, 95% CI 2.27-7.28, n = 5); Black Caribbean (RR 2.91, 95% CI 1.78-4.74, n = 16); South Asian (RR 1.71, 95% CI 1.07-2.72, n = 8); White Other (RR 1.55, 95% CI 1.32-1.83, n = 5); Mixed Ethnicity (RR 6.16, 95% CI 3.99-9.52, n = 4).

CONCLUSIONS

The risk for a diagnosis of non-affective and affective psychoses is particularly elevated for Black ethnic groups, but is higher for all ethnic minority groups including those previously not assessed through meta-analyses (White Other, Mixed Ethnicity). This calls for further research on broader disadvantages affecting ethnic minority people.

A systematic review and meta-analysis of the incidence of psychotic disorders: the distribution of rates and the influence of gender, urbanicity, immigration and socio-economic level

BACKGROUND

Considering existing knowledge on the relationship between certain environmental factors and incidence rates of psychosis, we carried out a systematic review to provide a broad and updated picture of the incidences of different psychotic disorder subgroups worldwide and how some environmental factors influence these rates.

METHODS

Studies with original data related to the incidence of psychosis (published between 2000 and 2015) were identified via searching electronic databases (CINAHL, MEDLINE, PSYCINFO, PUBMED, and SCOPUS). Data on the following risk factors were extracted: gender, urbanicity, immigration and socio-economic level. Descriptive appraisals of variation in incidence rates (IR) and incidence rate ratios (IRR), with a 95% confidence interval were calculated. In addition, a meta-analysis was performed to calculate IR pooled by diagnosis group and IRR pooled by diagnosis and gender, urbanity, immigration and socio-economic level, using a random effects model.

RESULTS

We identified 33 reports to analyse. Overall IR per 100 000 persons for non-affective psychoses (IR pooled = 22.53 (16.51-28.54)) were higher than affective psychoses (IR pooled = 7.12 (5.03-9.22)). There was an increase in rates of psychosis in men v. women (IRR pooled = 1.54 (1.37-1.72)), in urban v. rural areas (IRR pooled = 1.64 (1.38-1.95)), in immigrants v. natives (IRR pooled = 3.09 (2.74-3.49)), and in lower socio-economic level areas (IRR pooled = 1.78 (1.43-2.22)).

CONCLUSIONS

IR among different psychotic disorders was found to vary depending on gender, urbanicity, and immigration (as most of the previous literature focuses on non-affective psychosis or schizophrenia).

Cumulative Effects of Neighborhood Social Adversity and Personal Crime Victimization on Adolescent Psychotic Experiences

BACKGROUND

Little is known about the impact of urbanicity, adverse neighborhood conditions and violent crime victimization on the emergence of adolescent psychotic experiences.

METHODS

Participants were from the Environmental Risk (E-Risk) Longitudinal Twin Study, a nationally-representative cohort of 2232 British twins who were interviewed about adolescent psychotic experiences at age 18. Urbanicity, neighborhood characteristics, and personal victimization by violent crime were measured during childhood and adolescence via geocoded census data, surveys of over 5000 immediate neighbors of the E-Risk participants, and interviews with participants themselves.

RESULTS

Adolescents raised in urban vs rural neighborhoods were significantly more likely to have psychotic experiences (OR = 1.67, 95% CI = 1.21-2.30, P = .002). This association remained significant after considering potential confounders including family socioeconomic status, family psychiatric history, and adolescent substance problems (OR = 1.43, 95% CI = 1.01-2.03, P = .042), but became nonsignificant after considering adverse social conditions in urban neighborhoods such as low social cohesion and high neighborhood disorder (OR = 1.35, 95% CI = 0.94-1.92, P = .102). The combined association of adverse neighborhood social conditions and personal crime victimization with adolescent psychotic experiences (adjusted OR = 4.86, 95% CI = 3.28-7.20, P < .001) was substantially greater than for either exposure alone, highlighting a potential interaction between neighborhood conditions and crime victimization (interaction contrast ratio = 1.81, 95% CI = -0.03 to 3.65) that was significant at the P = .054 level.

CONCLUSIONS

Cumulative effects of adverse neighborhood social conditions and personal victimization by violent crime during upbringing partly explain why adolescents in urban settings are more likely to report psychotic experiences. Early intervention efforts for psychosis could be targeted towards victimized youth living in urban and socially adverse neighborhoods.

Ethnic Minority Status, Age-at-Immigration and Psychosis Risk in Rural Environments: Evidence From the SEPEA Study

OBJECTIVE

Several ethnic minority groups experience elevated rates of first-episode psychosis (FEP), but most studies have been conducted in urban settings. We investigated whether incidence varied by ethnicity, generation status, and age-at-immigration in a diverse, mixed rural, and urban setting.

METHOD

We identified 687 people, 16-35 years, with an ICD-10 diagnosis of FEP, presenting to Early Intervention Psychosis services in the East of England over 2 million person-years. We used multilevel Poisson regression to examine incidence variation by ethnicity, rural-urban setting, generation status, and age-at-immigration, adjusting for several confounders including age, sex, socioeconomic status, population density, and deprivation.

RESULTS

People of black African (incidence rate ratio: 4.06; 95% confidence interval [CI]: 2.63-6.25), black Caribbean (4.63; 95% CI: 2.38-8.98) and Pakistani (2.31; 95% CI: 1.35-3.94) origins were at greatest FEP risk relative to the white British population, after multivariable adjustment. Non-British white migrants were not at increased FEP risk (1.00; 95% CI: 0.77-1.32). These patterns were independently present in rural and urban settings. For first-generation migrants, migration during childhood conferred greatest risk of psychotic disorders (2.20; 95% CI: 1.33-3.62).

CONCLUSIONS

Elevated psychosis risk in several visible minority groups could not be explained by differences in postmigratory socioeconomic disadvantage. These patterns were observed across rural and urban areas of our catchment, suggesting that elevated psychosis risk for some ethnic minority groups is not a result of selection processes influencing rural-urban living. Timing of exposure to migration during childhood, an important social and neurodevelopmental window, may also elevate risk.

Gender matters in schizophrenia-spectrum disorders: Results from a healthcare users epidemiological study in Malaga, Spain

PURPOSE

Women suffering from schizophrenia-spectrum disorders may differ from men in clinical course and outcome. Still, those differences can only be portrayed accurately by means of studies that derive information from multiple sources. One such study was performed in a well-defined area supported by a Mental Health Clinical Management Unit in Malaga, Spain.

METHODS

Data from 1640 patients (1048 men and 592 women) that were in contact with services during 2008 were examined for the purpose of the present analysis. Gender differences in sociodemographic and clinical characteristics and the role of gender for explaining clinical characteristics (diagnosis, disease severity and service use) beyond potential sociodemographic confounders were explored.

RESULTS

The chi-squared analysis results revealed that in comparison to men, women were older, married or widowed/divorced and living as housewives with their families in cities. Genders also differed across diagnoses, with men being at higher risk for suffering from paranoid schizophrenia, while women being at higher risk for persistent delusional, acute/transitory and schizoaffective disorders. Furthermore, men had greater disease severity and higher chances to visit the mental health rehabilitation unit (MHRU). Further regression analyses revealed that after controlling for confounders, gender differences remained significant across diagnoses and severity. However, they lost their significance under the influence of marital, living and occupational status when predicting the use of MHRU.

CONCLUSION

Results confirm the existence of gender differences and highlight the importance of other factors for designing effective psychosocial services that are tailor-made to the patients' needs.

Why Are Children in Urban Neighborhoods at Increased Risk for Psychotic Symptoms? Findings From a UK Longitudinal Cohort Study

BACKGROUND

Urban upbringing is associated with a 2-fold adulthood psychosis risk, and this association replicates for childhood psychotic symptoms. No study has investigated whether specific features of urban neighborhoods increase children's risk for psychotic symptoms, despite these early psychotic phenomena elevating risk for schizophrenia and other psychiatric disorders in adulthood.

METHODS

Analyses were conducted on over 2000 children from the Environmental Risk (E-Risk) Longitudinal Twin Study, a nationally-representative cohort of UK-born twins. Neighborhood-level characteristics were assessed for each family via: a geodemographic discriminator indexing neighborhood-level deprivation, postal surveys of over 5000 residents living alongside the children, and in-home interviews with the children's mothers. Children were interviewed about psychotic symptoms at age 12. Analyses were adjusted for important family-level confounders including socioeconomic status (SES), psychiatric history, and maternal psychosis.

RESULTS

Urban residency at age-5 (OR = 1.80, 95% CI = 1.16-2.77) and age-12 (OR = 1.76, 95% CI = 1.15-2.69) were both significantly associated with childhood psychotic symptoms, but not with age-12 anxiety, depression, or antisocial behavior. The association was not attributable to family SES, family psychiatric history, or maternal psychosis, each implicated in childhood mental health. Low social cohesion, together with crime victimization in the neighborhood explained nearly a quarter of the association between urbanicity and childhood psychotic symptoms after considering family-level confounders.

CONCLUSIONS

Low social cohesion and crime victimization in the neighborhood partly explain why children in cities have an elevated risk of developing psychotic symptoms. Greater understanding of the mechanisms leading from neighborhood-level exposures to psychotic symptoms could help target interventions for emerging childhood psychotic symptoms.

Persons with schizophrenia migrate towards urban areas due to the development of their disorder or its prodromata

BACKGROUND

Many studies have identified urban-rural differences in the occurrence of schizophrenia. Though unknown, the underlying causes responsible for these differences have been hypothesized to include urban-rural differences in toxic exposures, diet, infections, stress, or an artifact due to selective migration. Freeman hypothesized that persons with schizophrenia migrate towards larger cities due to development of their disorder or its prodromata. Based on this, the reason for the high frequency of schizophrenia in urban areas is not that those affected have lived in environmentally unfavorable areas, but that people with schizophrenia selectively migrate towards urban areas due to disease onset. No population-based studies accessed the extent and potential impact of this artifact of selective migration.

METHODS

Utilizing a population-based sample of the Danish population, it was investigated if persons with schizophrenia more often migrated towards larger cities due to disease onset. The impact of selective migration on the urban-rural differences was quantified comparing a prospective and a retrospective study.

RESULTS

Compared to healthy controls, persons with schizophrenia spectrum disorder migrate to a higher degree of urbanization due to disease onset (OR=1.18 (1.14-1.23)). However, the bias in urban-rural effect sizes due to this artifact of selective migration was limited.

CONCLUSION

Persons with schizophrenia drift towards urban areas as a consequence of the disorder or its prodromata, but this drift has only limited impact on the urban-rural differences. Therefore, prospective and retrospective studies are both informative on the unknown underlying factor or factors responsible for the urban-rural differences in schizophrenia risk.

Social and spatial heterogeneity in psychosis proneness in a multilevel case-prodrome-control study

OBJECTIVE

To test whether spatial and social neighbourhood patterning of people at ultra-high risk (UHR) of psychosis differs from first-episode psychosis (FEP) participants or controls and to determine whether exposure to different social environments is evident before disorder onset.

METHOD

We tested differences in the spatial distributions of representative samples of FEP, UHR and control participants and fitted two-level multinomial logistic regression models, adjusted for individual-level covariates, to examine group differences in neighbourhood-level characteristics.

RESULTS

The spatial distribution of controls (n = 41) differed from UHR (n = 48; P = 0.04) and FEP participants (n = 159; P = 0.01), whose distribution was similar (P = 0.17). Risk in FEP and UHR groups was associated with the same neighbourhood-level exposures: proportion of single-parent households [FEP adjusted odds ratio (aOR): 1.56 95% CI: 1.00-2.45; UHR aOR: 1.59; 95% CI: 0.99-2.57], ethnic diversity (FEP aOR: 1.27; 95% CI: 1.02-1.58; UHR aOR: 1.28; 95% CI: 1.00-1.63) and multiple deprivation (FEP aOR: 0.88; 95% CI: 0.78-1.00; UHR aOR: 0.86; 95% CI: 0.76-0.99).

CONCLUSION

Similar neighbourhood-level exposures predicted UHR and FEP risk, whose residential patterning was closer to each other's than controls. Adverse social environments are associated with psychosis before FEP onset.

Urban living and psychosis--an overview

Since more than half a century, the association of urbanicity with psychosis has been explored. The research interest initially stemmed from the finding of a higher proportion of cases of psychotic disorder coming for treatment from the inner parts of cities. Subsequently, interest in the relationship of urbanicity and schizophrenia expanded and various facets of this association were explored. This narrative review provides an overview of the relationship between urbanicity and psychosis, and evaluates the link from the standpoint of causality. The review further delves into the possible risk factors and mechanisms explaining this association; both biological ones like genetic vulnerability and infections, as well as environmental ones like pollution. Since the literature has primarily emerged from the developed western countries, the review draws attention to the caveats while extrapolating the results to a developing country scenario.

The Concept of Schizophrenia: From Unity to Diversity

After over 100 years of research without clarifying the aetiology of schizophrenia, a look at the current state of knowledge in epidemiology, genetics, precursors, psychopathology, and outcome seems worthwhile. The disease concept, created by Kraepelin and modified by Bleuler, has a varied history. Today, schizophrenia is considered a polygenic disorder with onset in early adulthood, characterized by irregular psychotic episodes and functional impairment, but incident cases occur at all ages with marked differences in symptoms and social outcome. Men’s and women’s lifetime risk is nearly the same. At young age, women fall ill a few years later and less severely than men, men more rarely and less severely later in life. The underlying protective effect of oestrogen is antagonized by genetic load. The illness course is heterogeneous and depressive mood the most frequent symptom. Depression and schizophrenia are functionally associated, and affective and nonaffective psychoses do not split neatly. Most social consequences occur at the prodromal stage. Neither schizophrenia as such nor its main symptom dimensions regularly show pronounced deterioration over time. Schizophrenia is neither a residual state of a neurodevelopmental disorder nor a progressing neurodegenerative process. It reflects multifactorial CNS instability, which leads to cognitive deficits and symptom exacerbations.

Social deprivation, inequality, and the neighborhood-level incidence of psychotic syndromes in East London

Although urban birth, upbringing, and living are associated with increased risk of nonaffective psychotic disorders, few studies have used appropriate multilevel techniques accounting for spatial dependency in risk to investigate social, economic, or physical determinants of psychosis incidence. We adopted Bayesian hierarchical modeling to investigate the sociospatial distribution of psychosis risk in East London for DSM-IV nonaffective and affective psychotic disorders, ascertained over a 2-year period in the East London first-episode psychosis study. We included individual and environmental data on 427 subjects experiencing first-episode psychosis to estimate the incidence of disorder across 56 neighborhoods, having standardized for age, sex, ethnicity, and socioeconomic status. A Bayesian model that included spatially structured neighborhood-level random effects identified substantial unexplained variation in nonaffective psychosis risk after controlling for individual-level factors. This variation was independently associated with greater levels of neighborhood income inequality (SD increase in inequality: Bayesian relative risks [RR]: 1.25; 95% CI: 1.04-1.49), absolute deprivation (RR: 1.28; 95% CI: 1.08-1.51) and population density (RR: 1.18; 95% CI: 1.00-1.41). Neighborhood ethnic composition effects were associated with incidence of nonaffective psychosis for people of black Caribbean and black African origin. No variation in the spatial distribution of the affective psychoses was identified, consistent with the possibility of differing etiological origins of affective and nonaffective psychoses. Our data suggest that both absolute and relative measures of neighborhood social composition are associated with the incidence of nonaffective psychosis. We suggest these associations are consistent with a role for social stressors in psychosis risk, particularly when people live in more unequal communities.

Urbanicity, social adversity and psychosis

In recent years, there has been increasing interest in research on geographical variation in the incidence of schizophrenia and other psychoses. In this paper, we review the evidence on variation in incidence of schizophrenia and other psychoses in terms of place, as well as the individual- and area-level factors that account for this variation. We further review findings on potential mechanisms that link adverse urban environment and psychosis. There is evidence from earlier and more recent studies that urbanicity is associated with an increased incidence of schizophrenia and non-affective psychosis. In addition, considerable variation in incidence across neighbourhoods has been observed for these disorders. Findings suggest it is unlikely that social drift alone can fully account for geographical variation in incidence. Evidence further suggests that the impact of adverse social contexts - indexed by area-level exposures such as population density, social fragmentation and deprivation - on risk of psychosis is explained (confounding) or modified (interaction) by environmental exposures at the individual level (i.e., cannabis use, social adversity, exclusion and discrimination). On a neurobiological level, several studies suggest a close link between social adversity, isolation and stress on the one hand, and monoamine dysfunction on the other, which resembles findings in schizophrenia patients. However, studies directly assessing correlations between urban stress or discrimination and neurobiological alterations in schizophrenia are lacking to date.

A review of the reliability and validity of OPCRIT in relation to its use for the routine clinical assessment of mental health patients

The OPCRIT program is a symptom checklist with accompanying algorithms producing operationally defined diagnoses. We undertook a review of studies which had used OPCRIT and had reported statistics concerning its reliability and validity, producing summary measures from 44 studies. The first main measure of interest was inter-rater reliability where mean kappa values indicated that agreement between raters was "substantial" with a marginal improvement at the diagnostic (0.76) versus individual item (0.69) level. The second main measure of interest was convergent validity - the agreement between OPCRIT and clinical diagnoses. Most studies reported these figures as concordance rates suggesting mean agreement, unadjusted for chance, of 69%. Very few studies used the chance-adjusted kappa statistic but where this was used agreement was "fair" (0.39). Agreement between OPCRIT and other research diagnoses was "moderate" (0.60). We also considered differences between the way OPCRIT has traditionally been used in research settings and the naturalistic manner in which it will be employed in the hospital ward. This review provides a summary of the reliability and validity of OPCRIT, which will be considered during the preparation for its use in the routine characterization of mental health patients in clinical settings.

Has the prevalence, clinical presentation and social functioning of schizophrenia changed over the last 25 years? Nithsdale schizophrenia survey revisited

BACKGROUND

Major changes in the treatment of schizophrenia have taken place in recent years, including a shift from inpatient to community care, and the introduction of second-generation antipsychotics and psychosocial interventions. Recent evidence has questioned the superiority of these interventions over older treatments.

AIMS

We wished to ascertain the impact of changes in the treatment of schizophrenia in a geographically-defined area, focusing on clinical symptoms and psychosocial outcome.

METHODS

In 2006, we replicated the survey carried out in 1981, identifying the population of people with schizophrenia living in Nithsdale, South-West Scotland, measuring prevalence using the 'key informant' method. We assessed their clinical and social functioning, using similar scales, and compared measures across both time periods.

RESULTS

We identified 205 people with schizophrenia, a point prevalence of 3.59/1000 general population. In 2006, while fewer people experienced negative symptoms, a greater number experienced positive symptoms. There were no significant differences in the prevalence of tardive dyskinesia or Parkinsonism, though tremor was less common in the 2006 population. In 2006, there were fewer people living with a spouse/partner or parents, and fewer were in open employment in comparison to the 1981 population. The overall level of social adjustment had not changed.

CONCLUSIONS

The clinical manifestation of schizophrenia appears to have changed over the last 25 years, within this geographically-defined area, the prevalence of negative symptoms having decreased, and positive symptoms seem to have increased. The level of social functioning does not appear to have changed over the last 25 years.

Unemployment, ethnicity and psychosis

OBJECTIVE

This study describes the incidence of psychosis in unemployed people and determines whether unemployment has a greater impact on the development of psychosis amongst Black minority groups than White groups.

METHOD

Patients with a first diagnosis of Research Diagnostic Criteria psychosis, in a defined area of London from 1998 to 2004, were identified. Crude and standardised incidence rates of psychosis amongst unemployed people for each ethnic group were calculated. Poisson regression modelling tested for interactions between unemployment and ethnicity.

RESULTS

Hundred cases occurred amongst employed people and 78 cases occurred amongst the unemployed people. When standardised to the employed White population of the area, White unemployed people had a standardised incidence ratio (SIR) of 11.7 (95% CI 6.4-19.7), Black Caribbean people had a SIR of 60.1(95% CI 39.3-88) and Black African people had a SIR of 40.7 (95% CI 25.8-61.1). There was no interaction however between ethnicity and unemployment (Likelihood ratio test P = 0.54).

CONCLUSION

Rates of psychosis are high amongst unemployed people in south London and extremely high amongst Black Caribbean and Black African unemployed people. There was no evidence however that the minority groups were particularly sensitive to the stresses, limitations or meaning of unemployment.

Meta-analysis of the association of urbanicity with schizophrenia

The association between urbanicity and risk of schizophrenia is well established. The incidence of schizophrenia has been observed to increase in line with rising levels of urbanicity, as measured in terms of population size or density. This association is expressed as Incidence Rate Ratio (IRR), and the results are usually presented by comparing the most urban with the most rural environment. In this study, we undertook to express the effect of urbanicity on the risk of schizophrenia in a linear form and to perform a meta-analysis of all available evidence. We first employed a simple regression analysis of log (IRR) as given in each study on the urbanicity category, assuming a uniform distribution and a linear association. In order to obtain more accurate estimates, we developed a more sophisticated method that generates individual data points with simulation from the summary data presented in the original studies, and then fits a logistic regression model. The estimates from each study were combined with meta-analysis. Despite the challenges that arise from differences between studies as regards to the number and relative size of urbanicity levels, a linear association was observed between the logarithm of the odds of risk for schizophrenia and urbanicity. The risk for schizophrenia at the most urban environment was estimated to be 2.37 times higher than in the most rural environment. The same effect was found when studies measuring the risk for nonaffective psychosis were included.

Incidence of schizophrenia and other psychoses in England, 1950-2009: a systematic review and meta-analyses

BACKGROUND

We conducted a systematic review of incidence rates in England over a sixty-year period to determine the extent to which rates varied along accepted (age, sex) and less-accepted epidemiological gradients (ethnicity, migration and place of birth and upbringing, time).

OBJECTIVES

To determine variation in incidence of several psychotic disorders as above.

DATA SOURCES

Published and grey literature searches (MEDLINE, PSycINFO, EMBASE, CINAHL, ASSIA, HMIC), and identification of unpublished data through bibliographic searches and author communication.

STUDY ELIGIBILITY CRITERIA

Published 1950-2009; conducted wholly or partially in England; original data on incidence of non-organic adult-onset psychosis or one or more factor(s) pertaining to incidence.

PARTICIPANTS

People, 16-64 years, with first -onset psychosis, including non-affective psychoses, schizophrenia, bipolar disorder, psychotic depression and substance-induced psychosis.

STUDY APPRAISAL AND SYNTHESIS METHODS

Title, abstract and full-text review by two independent raters to identify suitable citations. Data were extracted to a standardized extraction form. Descriptive appraisals of variation in rates, including tables and forest plots, and where suitable, random-effects meta-analyses and meta-regressions to test specific hypotheses; rate heterogeneity was assessed by the I²-statistic.

RESULTS

83 citations met inclusion. Pooled incidence of all psychoses (N = 9) was 31.7 per 100,000 person-years (95%CI: 24.6-40.9), 23.2 (95%CI: 18.3-29.5) for non-affective psychoses (N = 8), 15.2 (95%CI: 11.9-19.5) for schizophrenia (N = 15) and 12.4 (95%CI: 9.0-17.1) for affective psychoses (N = 7). This masked rate heterogeneity (I²: 0.54-0.97), possibly explained by socio-environmental factors; our review confirmed (via meta-regression) the typical age-sex interaction in psychosis risk, including secondary peak onset in women after 45 years. Rates of most disorders were elevated in several ethnic minority groups compared with the white (British) population. For example, for schizophrenia: black Caribbean (pooled RR: 5.6; 95%CI: 3.4-9.2; N = 5), black African (pooled RR: 4.7; 95%CI: 3.3-6.8; N = 5) and South Asian groups in England (pooled RR: 2.4; 95%CI: 1.3-4.5; N = 3). We found no evidence to support an overall change in the incidence of psychotic disorder over time, though diagnostic shifts (away from schizophrenia) were reported.

LIMITATIONS

Incidence studies were predominantly cross-sectional, limiting causal inference. Heterogeneity, while evidencing important variation, suggested pooled estimates require interpretation alongside our descriptive systematic results.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

Incidence of psychotic disorders varied markedly by age, sex, place and migration status/ethnicity. Stable incidence over time, together with a robust socio-environmental epidemiology, provides a platform for developing prediction models for health service planning.

Administrative incidence of psychosis assessed in an early intervention service in England: first epidemiological evidence from a diverse, rural and urban setting

BACKGROUND

Early Intervention in Psychosis Services (EIS) for young people in England experiencing first-episode psychosis (FEP) were commissioned in 2002, based on an expected incidence of 15 cases per 100 000 person-years, as reported by schizophrenia epidemiology in highly urban settings. Unconfirmed reports from EIS thereafter have suggested higher than anticipated rates. The aim of this study was to compare the observed with the expected incidence and delineate the clinical epidemiology of FEP using epidemiologically complete data from the CAMEO EIS, over a 6-year period in Cambridgeshire, for a mixed rural-urban population.

METHOD

A population-based study of FEP (ICD-10, F10-39) in people aged 17-35 years referred between 2002 and 2007; the denominator was estimated from mid-year census statistics. Sociodemographic variation was explored by Poisson regression. Crude and directly standardized rates (for age, sex and ethnicity) were compared with pre-EIS rates from two major epidemiological FEP studies conducted in urban English settings.

RESULTS

A total of 285 cases met FEP diagnoses in CAMEO, yielding a crude incidence of 50 per 100 000 person-years [95% confidence interval (CI) 44.5-56.2]. Age- and sex-adjusted rates were raised for people from black ethnic groups compared with the white British [incidence rate ratio (IRR) 2.1, 95% CI 1.1-3.8]. Rates in our EIS were comparable with pre-EIS rates observed in more urban areas after age, sex and ethnicity standardization.

CONCLUSIONS

Our findings suggest that the incidence observed in EIS is far higher than originally anticipated and is comparable to rates observed in more urban settings prior to the advent of EIS. Sociodemographic variation due to ethnicity and other factors extend beyond urban populations. Our results have implications for psychosis aetiology and service planning.

Early risk factors for suicide in an epidemiological first episode psychosis cohort

BACKGROUND

Much remains unknown about whether there are early risk factors for suicide in psychosis.

AIM

The aim of the study was to determine whether there are any identifiable early symptom clusters, aetiological factors or illness course markers for suicide in first episode psychosis.

METHOD

A total of 2132 patients with first episode psychosis presenting to secondary care services in London (1965-2004; n=1474), Nottingham (1997-1999; n=195) and Dumfries and Galloway (1979-1998; n=463) were traced after up to 40 years (mean 13 years) following first presentation. Risk factors were identified from the Operational Checklist for Psychotic Disorders rated for the first year following presentation.

RESULTS

Overall, there were 51 suicides and 373 deaths from other causes. Male gender (RR 2.84, 95% CI 1.20-6.69, p=0.02) and a cumulative threshold effect of symptoms early in the illness (RR 6.81, 95% CI 2.33-19.85, p<0.001) were associated with a higher propensity for later completed suicide. There was also a suggestion that early manic symptoms might increase the risk of later suicide irrespective of initial diagnosis.

CONCLUSION

Suicide risk was associated with a cumulative threshold effect of symptoms and manic symptoms. As suicide is a relatively rare event in psychotic disorders, general population-based prevention strategies may have more impact in this vulnerable group as well as the wider population.

Effects of plasma magnesium and prolactin on quantitative ultrasound measurements of heel bone among schizophrenic patients

BACKGROUND

Osteoporosis is a bone disease that can reduce both bone mass and bone strength. It can cause serious fractures of bones, along with causing significant and even devastating physical, psychological and financial consequences for patients and their family members. Many reports have revealed that the prevalence of decreased bone density is higher in schizophrenic patients than in the non-psychological diseased population. The previous report of our group revealed that chronic schizophrenia patients have poorer BUA levels since they were young as compared to the general community population. Hyperprolactinemia and antipsychotics are reported to be among the risk factors for osteoporosis in chronic schizophrenic patients.

METHODS

93 schizophrenic patients with severely poor adjusted BUA values and 93 age and gender matched patients with normal adjusted BUA values from a previous survey study were selected. Data were collected via questionnaires and via reviews of antipsychotic medications. Blood samples were drawn, and serum levels of prolactin, estradiol, testosterone, magnesium, calcium, phosphate, osteocalcin, Cross-linked N-teleopeptide of type I collagen (NTX), thyroid hormone and parathyroid hormone were checked. The association between BUA levels and serum levels of the above items, along with the type of received antipsychotic medication, was evaluated.

RESULTS

There was no significant association found between reduced BUA levels and serum prolactin, calcium, phosphate, osteocalcin, NTX, thyroid stimulating hormone and parathyroid hormone levels. There was also no association between BUA levels and types of currently received antipsychotics. There was no association between BUA levels and menstruation condition in female patients. Hypermagnesemia had a borderline association with classical and combined (classical and atypical) antipsychotic medications in male patients. Nevertheless, hypermagnesemia is a significant protective factor of reduced BUA levels in female patients. Hyperprolactinemia had a significant association with classical and combined antipsychotic medications in female patients. Hyperprolactinemia, however, provides a protective effect on reduced BUA levels in male patients. There was no significant association found between serum prolactin level and the type of antipsychotic medication received.

CONCLUSIONS

The results of this study are in contrast with literature that has reported an association between bone mass and serum prolactin levels, serum magnesium levels and type of received antipsychotics. Further study to investigate the pathophysiological process and the association between bone mass and serum prolactin level, serum magnesium level and specific antipsychotics is necessary.

Prevalence and correlates of auditory vocal hallucinations in middle childhood

BACKGROUND

Hearing voices occurs in middle childhood, but little is known about prevalence, aetiology and immediate consequences.

AIMS

To investigate prevalence, developmental risk factors and behavioural correlates of auditory vocal hallucinations in 7- and 8-year-olds.

METHOD

Auditory vocal hallucinations were assessed with the Auditory Vocal Hallucination Rating Scale in 3870 children. Prospectively recorded data on pre- and perinatal complications, early development and current problem behaviour were analysed in children with auditory vocal hallucinations and matched controls.

RESULTS

The 1-year prevalence of auditory vocal hallucinations was 9%, with substantial suffering and problem behaviour reported in 15% of those affected. Prevalence was higher in rural areas but auditory vocal hallucinations were more severe and had greater functional impact in the urban environment. There was little evidence for associations with developmental variables.

CONCLUSIONS

Auditory vocal hallucinations in 7- and 8-year-olds are prevalent but mostly of limited functional impact. Nevertheless, there may be continuity with more severe psychotic outcomes given the serious suffering in a subgroup of children and there is evidence for a poorer prognosis in an urban environment.

Schizophrenia and the city: A review of literature and prospective study of psychosis and urbanicity in Ireland

Urbanicity has been repeatedly associated with increased incidence of schizophrenia. This article (a) presents results of a prospective study of urbanicity and schizophrenia in Ireland and (b) reviews the literature relating to urbanicity and schizophrenia. We prospectively compared incidence of schizophrenia and other psychoses in urban and rural catchment areas (over 4years and 7years, respectively) using face-to-face, DSM-III-R diagnostic interviews. Incidence of schizophrenia in males was higher in urban compared to rural areas, with an age-adjusted incidence rate ratio (IRR) of 1.92 (1.52-2.44) for males and 1.34 (1.00-1.80) for females. Incidence of affective psychosis was lower in urban compared to rural areas for males (IRR 0.48; 0.34-0.67) and females (IRR 0.60; 0.43-0.83). These findings are consistent with the literature, which provides persuasive evidence that risk for schizophrenia increases with urban birth and/or upbringing, especially among males. Register-based studies support this conclusion more consistently than studies using face-to-face diagnostic interviews, the difference being related to power. The mechanism of association is unclear but may relate to biological or social/environmental factors or both, acting considerably before psychotic symptoms manifest. There is a diversity of potential candidates, including air pollution, cannabis and social exclusion. Urbanicity may have a synergistic effect with genetic vulnerability. Future research is likely to focus on the relationship between urbanicity and neural maldevelopment, the possibility of rural protective factors (e.g. social capital, low social fragmentation), urbanicity in developing countries, cultural variables and geographical location, and associations between urbanicity and other disorders (e.g. affective psychosis).

Standardisation of rates using logistic regression: a comparison with the direct method

Background

Standardisation of rates in health services research is generally undertaken using the direct and indirect arithmetic methods. These methods can produce unreliable estimates when the calculations are based on small numbers. Regression based methods are available but are rarely applied in practice. This study demonstrates the advantages of using logistic regression to obtain smoothed standardised estimates of the prevalence of rare disease in the presence of covariates.

Methods

Step by step worked examples of the logistic and direct methods are presented utilising data from BETS, an observational study designed to estimate the prevalence of subclinical thyroid disease in the elderly. Rates calculated by the direct method were standardised by sex and age categories, whereas rates by the logistic method were standardised by sex and age as a continuous variable.

Results

The two methods produce estimates of similar magnitude when standardising by age and sex. The standard errors produced by the logistic method were lower than the conventional direct method.

Conclusion

Regression based standardisation is a practical alternative to the direct method. It produces more reliable estimates than the direct or indirect method when the calculations are based on small numbers. It has greater flexibility in factor selection and allows standardisation by both continuous and categorical variables. It therefore allows standardisation to be performed in situations where the direct method would give unreliable results.

Psychosis and place

One important line of epidemiologic inquiry implicating social context in the etiology of psychosis is the examination of spatial variation in the distribution of psychotic illness. The authors conducted a systematic review of evidence from urbanicity and neighborhood studies regarding spatial variation in the incidence of psychosis in developed countries since 1950. A total of 44 studies (20 of urbanicity and 24 of neighborhood) were culled from three databases with similar time frames: Medline (1950-2007), PsychInfo (1950-2007), and Sociological Abstracts (1952-2007). With a special emphasis on social factors potentially relevant to etiology, the authors elucidated contributions, limitations, and issues related to study design, measurement, and theory. Evidence from both arenas supports a possible etiologic role for social context. Studies of urbanicity indicate that early-life exposure may be important; dose-response relations, spatial patterning of schizophrenia, and interactions with other factors may exist. Neighborhood studies indicate heterogeneity in rates, hint at spatial patterning of schizophrenia, and offer intriguing evidence implying more proximal social (as opposed to physical) exposures. The authors encourage the exploration of social pathways engaging theory, methodological advances, and the life-course perspective. They also propose a conceptual shift from studies of spatial variation in outcomes to research addressing the etiologic effect of exposures shaped by place as a reservoir of risk or resilience.

Hospital-treated psychosis and suicide in a rural community (1877-2005). Part 2: Genetic founder effects

OBJECTIVE

To demonstrate the existence of genetic founder effects in hospital-treated cases of psychosis and self-harm in historical cohorts of a small rural population.

METHOD

These cohorts consist of named persons born after 1845. The cumulative case registers were linked to the purported pedigrees of three presumed mentally ill founders living in the community in the 17th and 18th centuries. We compared the incidence of psychosis and self-harm in the genetically unexposed population and in three exposed founder populations.

RESULTS

We found a preponderance of organic mental disorders and schizophrenia in the twice-exposed founder population and of other non-organic psychosis and self-harm in the thrice-exposed founder population.

CONCLUSION

The genetic impact of the founders seems to have affected the incidence rates of severe psychiatric disorders of their descendants in two ways. A founder effect is detected in organic mental disorders and schizophrenia, and it seems to run independently of that detected in affective psychotic disorders and intentional self-harm.

A comparison of symptoms and family history in schizophrenia with and without prior cannabis use: implications for the concept of cannabis psychosis

BACKGROUND

There is considerable interest in cannabis use in psychosis. It has been suggested that the chronic psychosis associated with cannabis use, is symptomatically distinct from idiopathic schizophrenia. Several studies have reported differences in psychopathology and family history in people with schizophrenia according to whether or not they were cannabis users. We set out to test the hypotheses arising from these studies that cannabis use is associated with more bizarre behaviour, more thought disorder, fewer negative symptoms including blunted affect, more delusions of reference, more paranoid delusions and a stronger family history of schizophrenia.

METHOD

We used a case register that contained 757 cases of first onset schizophrenia, 182 (24%) of whom had used cannabis in the year prior to first presentation, 552 (73%) had not and 3% had missing data. We completed the OPCRIT checklist on all patients and investigated differences in the proportion of people with distractibility, bizarre behaviour, positive formal thought disorder, delusions of reference, well organised delusions, any first rank symptom, persecutory delusions, abusive/accusatory hallucinations, blunted affect, negative thought disorder, any negative symptoms (catatonia, blunted affect, negative thought disorder, or deterioration), lack of insight, suicidal ideation and a positive family history of schizophrenia, using chi square tests. Logistic regression modelling was then used to determine whether prior cannabis use affected the presence of the characteristics after controlling for age, sex and ethnicity.

RESULTS

There was no statistically significant effect of cannabis use on the presence of any of the above. There remained however a non-significant trend towards more insight (OR 0.65 p=0.055 for "loss of insight") and a finding of fewer abusive or accusatory hallucinations (OR 0.65 p=0.049) of borderline significance amongst the cannabis users. These were in the hypothesised direction. There was no evidence of fewer negative symptoms or greater family history amongst cannabis users.

CONCLUSION

We found few appreciable differences in symptomatology between schizophrenic patients who were or were not cannabis users. There were no differences in the proportion of people with a positive family history of schizophrenia between cannabis users and non-users. This argues against a distinct schizophrenia-like psychosis caused by cannabis.

Social defeat and the culture of chronicity: or, why schizophrenia does so well over there and so badly here

The history of the way schizophrenia has been conceptualized in American psychiatry has led us to be hesitant to explore the role of social causation in schizophrenia. But there is now good evidence for social impact on the course, outcome, and even origin of schizophrenia, most notably in the better prognosis for schizophrenia in developing countries and in the higher rates of schizophrenia for dark-skinned immigrants to England and the Netherlands. This article proposes that "social defeat" may be one of the social factors that may impact illness experience and uses original ethnographic research to argue that social defeat is a common feature of the social context in which many people diagnosed with schizophrenia in America live today.

A comparison of the ethnic distribution in the depressed inpatient population and in the electroconvulsive therapy clinic

OBJECTIVES

It is often assumed that depressed members of ethnic minorities in Western countries are more likely to be treated with electroconvulsive therapy (ECT) than white patients. The aim of this study was to test such assumption in the area of London covered by our mental health Trust.

METHODS

We examined the electronic records of all admissions with a diagnosis of major depression (n = 2422) to the 3 hospitals in a London mental health Trust for a period of 4 years. Their ethnic characteristics were analyzed and compared, according to whether they had received ECT or not.

RESULTS

Depressed inpatients treated with ECT were more likely to be white than depressed inpatients who were not treated with ECT (odds ratio, 7.4; 95% confidence interval, 2.3-23.3). This excess remained significant after patients aged older than 65 years were excluded from the comparison.

CONCLUSIONS

This survey highlights the need to ensure that members of ethnic minorities have equal access to all effective psychiatric treatments, including ECT.

Treated incidence of first-episode psychosis in the catchment area of EPPIC between 1997 and 2000

OBJECTIVE

To identify the treated incidence of psychosis in catchment of the Early Psychosis Prevention and Intervention Centre (EPPIC), Melbourne, Australia.

METHOD

Cases were aged 15-29 years with a first episode of a psychotic disorder accepted into EPPIC between 1997 and 2000. Age- and sex-specific incidence rates per 10,000 person-years were calculated in 5 year age bands. Rate ratios were used for age group comparisons.

RESULTS

The age-specific treated incidence of first-episode psychosis in 15-29-year old individuals was 16.7 per 10,000 person-years in males, and 8.1 per 10,000 person-years in females. The incidence was highest in 20-24-year-old males and in 15-19-year-old females. For both sexes, incidence rates were significantly lower in the 25-29-year age group.

CONCLUSIONS

The incidence of psychosis in the catchment of EPPIC was higher than previously reported, especially in female teenagers. Peak rates in 15-24 year olds suggest a youth model approach to early psychosis may be indicated.

Social fragmentation, deprivation and urbanicity: relation to first-admission rates for psychoses

BACKGROUND

Social disorganisation, fragmentation and isolation have long been posited as influencing the rate of psychoses at area level. Measuring such societal constructs is difficult. A census-based index measuring social fragmentation has been proposed.

AIMS

To investigate the association between first-admission rates for psychosis and area-based measures of social fragmentation, deprivation and urban/rural index.

METHOD

We used indirect standardisation methods and logistic regression models to examine associations of social fragmentation, deprivation and urban/rural categories with first admissions for psychoses in Scotland for the 5-year period 1989-1993.

RESULTS

Areas characterised by high social fragmentation had higher first-ever admission rates for psychosis independent of deprivation and urban/rural status. There was a dose-response relationship between social fragmentation category and first-ever admission rates for psychosis. There was no statistically significant interaction between social fragmentation, deprivation and urban/rural index.

CONCLUSIONS

First-admission rates are strongly associated with measures of social fragmentation, independent of material deprivation and urban/rural category.

Prevalence and incidence of schizophrenia among national health insurance enrollees in Taiwan, 1996-2001

As many as 96% of all residents of Taiwan have been enrolled in the National Health Insurance (NHI) program since 1996. The NHI database was used to examine the prevalence and incidence of schizoprenia. The National Health Research Institute provided a database of 200 432 random subjects, about 1% of the population, for study. By means of exclusion criteria, a random sample of 136 045 subjects as a fixed cohort dated from 1996-2001 was obtained. Those study subjects who had at least one service claim during these years for either ambulatory or inpatient care, with a principal diagnosis of schizophrenia, were identified. The cumulative prevalence increased from 3.34 per 1000 to 6.42 per 1000 from 1996 to 2001. The annual incidence density decreased from 0.95 per 1000/year to 0.45 per 1000/year from 1997 to 2001. Male subjects had higher treated prevalence in younger age groups than did female subjects. Higher prevalence was associated with the 25-44 and 45-64 age groups, insurance amount less than US$640, the eastern region, and suburban areas. Lower incidence was associated with the 45-64 age group. Higher incidence was associated with insurance amount less than US$640, and the eastern region. According to the trends of cumulative prevalence and incidence density, the treated prevalence and incidence rate will be approximate to community rates gradually. Most persons with schizophrenia had received treatment in Taiwan after the NHI program was implemented. Future studies should focus on outcome and cost evaluation.

Early intervention in first-episode psychosis--the impact of a community development campaign

OBJECTIVE

Substantial delays in providing access to treatment in first-episode psychosis have been well documented. The present study examines the impact of strategies aimed at improving access and reducing delays.

METHOD

A pilot community education campaign was conducted with the aim of reducing the duration of untreated psychosis (DUP) in a geographically defined intervention sector located in the northwestern region of Melbourne, Australia. Utilising a quasi-experimental design, a comparison sector with similar demographics was selected from another part of the north-western region. A mobile early detection team and the same treatment system served both sectors.

RESULTS

While there was no significant difference between the mean DUP for intervention and comparison sectors, the distributional features of DUP between the two regions were significantly different. In the intervention sector, disproportionately more cases with very long DUP were detected. When a small number of outliers were removed, the mean and median DUP in the intervention sector was reduced.

CONCLUSION

These findings highlight the complexity of treatment access and delay and suggest that efforts to reduce DUP may have two effects, not one. Firstly, a different sample of cases is treated through the detection of hidden "long DUP" cases that otherwise may have remained untreated. Secondly, the DUP for the remainder may indeed be reduced. More research with larger samples and more potent campaign strategies is clearly required. It may also be worth considering whether there is a safe and ethical way to undertake a RCT of early versus delayed antipsychotic treatment to perhaps settle the DUP debate once and for all.

Differences between indigenous Samis and Norwegians in mental disorders and background factors: patients listed as under treatment at the DPS-Lakselv (County District Psychiatric Centre), Finnmark, Spring 2000

BACKGROUND

Earlier comparisons of adult Samis and Norwegians living within the same area are--thus far--unknown concerning mental well being/health and possible background factors.

AIM

To compare patients from the two communities in search of differences which may be useful in planning health services.

METHOD

Retrospective and anonymised data collected from journals. Comprises 48 'Samis' and 70 'Norwegians' in 108 'demographic cells' according to ethnicity, sex, municipality, education and age.

RESULTS

'Samis' rated higher in schizophrenia/psychosis (0.05 < p < 0.1) and crises (0.1 < p < 0.25), 'Norwegians' rated higher in anxiety disorders (0.001 < p < 0.005), low self-esteem (0.005 < p < 0.01), illegal drugs (0.01 < p < 0.025) and in identity/existential problems (0.1 < p < 0.25). 'Samis' appeared to have suffered more at provincial boarding schools (0.005 < p < 0.01), while 'Norwegians' presented more mental illnesses in their families (0.025 < p < 0.05), more family break-ups (0.05 < p < 0.1) and earlier alcohol/drug abuse (0.05 < p < 0.1).

CONCLUSION

Significant differences were found. 'In the black box' results will raise interesting questions for further research, but will also be useful for planning health services.

A systematic review of the incidence of schizophrenia: the distribution of rates and the influence of sex, urbanicity, migrant status and methodology

BACKGROUND

Understanding variations in the incidence of schizophrenia is a crucial step in unravelling the aetiology of this group of disorders. The aims of this review are to systematically identify studies related to the incidence of schizophrenia, to describe the key features of these studies, and to explore the distribution of rates derived from these studies.

METHODS

Studies with original data related to the incidence of schizophrenia (published 1965-2001) were identified via searching electronic databases, reviewing citations and writing to authors. These studies were divided into core studies, migrant studies, cohort studies and studies based on Other Special Groups. Between- and within-study filters were applied in order to identify discrete rates. Cumulative plots of these rates were made and these distributions were compared when the underlying rates were sorted according to sex, urbanicity, migrant status and various methodological features.

RESULTS

We identified 100 core studies, 24 migrant studies, 23 cohort studies and 14 studies based on Other Special Groups. These studies, which were drawn from 33 countries, generated a total of 1,458 rates. Based on discrete core data for persons (55 studies and 170 rates), the distribution of rates was asymmetric and had a median value (10%-90% quantile) of 15.2 (7.7-43.0) per 100,000. The distribution of rates was significantly higher in males compared to females; the male/female rate ratio median (10%-90% quantile) was 1.40 (0.9-2.4). Those studies conducted in urban versus mixed urban-rural catchment areas generated significantly higher rate distributions. The distribution of rates in migrants was significantly higher compared to native-born; the migrant/native-born rate ratio median (10%-90% quantile) was 4.6 (1.0-12.8). Apart from the finding that older studies reported higher rates, other study features were not associated with significantly different rate distributions (e.g. overall quality, methods related to case finding, diagnostic confirmation and criteria, the use of age-standardization and age range).

CONCLUSIONS

There is a wealth of data available on the incidence of schizophrenia. The width and skew of the rate distribution, and the significant impact of sex, urbanicity and migrant status on these distributions, indicate substantial variations in the incidence of schizophrenia.

Incidence of schizophrenia in south-east London between 1965 and 1997

BACKGROUND

There has been much debate about changes in the incidence of schizophrenia.

AIMS

To identify any changes in incidence of schizophrenia in Camberwell, south-east London, between 1965 and 1997.

METHOD

Research Diagnostic Criteria and DSM-III-R diagnoses were generated for all first contacts by the OPCRIT computer program, and incidence rates of schizophrenia in seven time periods were measured. Indirect standardisation and Poisson models were used to measure the effect of time period and to examine interactions with age and gender.

RESULTS

There was a continuous and statistically significant increase in the incidence of schizophrenia, which was greatest in people under 35 years of age and was not gender-specific.

CONCLUSIONS

The incidence of schizophrenia has doubled in south-east London over the past three decades.