Migration, ethnicity, and psychosis: toward a sociodevelopmental model

Different rates of first admissions for psychosis in migrant groups in Paris

PURPOSE

The association between migration and psychosis has been reported in the past decades in many European countries. Despite large-scale migration into France, epidemiological data on the incidence of psychosis in this population are lacking. In this study, we compare the incidence rates of first admission for psychosis among natives and first generation migrants.

METHODS

Two-hundred and fifty-eight patients aged 15+ with first admission for psychosis were identified in the catchment area of the 20th district of Paris between 2005 and 2009. Standardised incidence rates and incidence rate ratios were calculated for migrant and native groups.

RESULTS

We found higher rates of admissions for psychosis in the migrant group (IRR 2.9, 95 % CI 0.9-9.8) compared to individuals born in France. Among migrants, incidence was higher in individuals from Sub-Saharan Africa compared to natives (IRR 7.1, CI 95 % 2.3-21.8), whereas the incidence was similar for those from Europe (IRR 1.2, CI 95 % 0.3-5.1) and from North Africa (IRR 1.4, CI 95 % 0.4-5.6).

CONCLUSIONS

Our findings suggest that Sub-Saharan migrants were identified as the most vulnerable migrant group for developing psychosis in France, but additional work is warranted to confirm these trends.

Identifying gene-environment interactions in schizophrenia: contemporary challenges for integrated, large-scale investigations

Recent years have seen considerable progress in epidemiological and molecular genetic research into environmental and genetic factors in schizophrenia, but methodological uncertainties remain with regard to validating environmental exposures, and the population risk conferred by individual molecular genetic variants is small. There are now also a limited number of studies that have investigated molecular genetic candidate gene-environment interactions (G × E), however, so far, thorough replication of findings is rare and G × E research still faces several conceptual and methodological challenges. In this article, we aim to review these recent developments and illustrate how integrated, large-scale investigations may overcome contemporary challenges in G × E research, drawing on the example of a large, international, multi-center study into the identification and translational application of G × E in schizophrenia. While such investigations are now well underway, new challenges emerge for G × E research from late-breaking evidence that genetic variation and environmental exposures are, to a significant degree, shared across a range of psychiatric disorders, with potential overlap in phenotype.

First-episode psychosis and migration in Italy (PEP-Ita migration): a study in the Italian mental health services

BACKGROUND

It has been frequently reported a higher incidence of psychotic disorders in immigrants than in native populations. There is, however, a lack of knowledge about risk factors which may explain this phenomenon. A better understanding of the causes of psychosis among first-generation migrants is highly needed, particularly in Italy, a country with a recent massive migration.

METHODS/DESIGN

The "Italian study on first-episode psychosis and migration (PEP-Ita)" is a prospective observational study over a two-year period (1 January 2012-31 December 2013) which will be carried out in 11 Italian mental health centres. All participating centres will collect data about all new cases of migrants with first-episode psychosis. The general purpose ("core") of the PEP-Ita study is to explore the socio-demographic and clinical characteristics, and the pathways to care of a population of first-episode psychosis migrants in Italy. Secondary aims of the study will be: 1) to understand risk and protective factors for the development of psychotic disorders in migrants; 2) to evaluate the correlations between psychopathology of psychotic disorders in migrants and socio-demographic characteristics, migration history, life experiences; 3) to evaluate the clinical and social outcomes of first-episode psychoses in migrants.

DISCUSSION

The results of the PEP-Ita study will allow a better understanding of risk factors for psychosis in first-generation migrants in Italy. Moreover, our results will contribute to the development of prevention programmes for psychosis and to the improvement of early intervention treatments for the migrant population in Italy.

Identifying aspects of neighbourhood deprivation associated with increased incidence of schizophrenia

BACKGROUND

Several studies have found an association between area deprivation and incidence of schizophrenia. However, not all studies have concurred and definitions of deprivation have varied between studies. Relative deprivation and inequality seem to be particularly important, but which aspects of deprivation or how this effect might operate is not known.

METHODS

The Lambeth Early Onset case register is a database of all cases of first episode psychosis aged 16 to 35years from the London Borough of Lambeth, a highly urban area. We identified 405 people with first onset schizophrenia who presented between 2000 and 2007. We calculated the overall incidence of first onset schizophrenia and tested for an association with area-level deprivation, using a multi-domain index of deprivation (IMD 2004). Specific analyses into associations with individual sub-domains of deprivation were then undertaken.

RESULTS

Incidence rates, directly standardized for age and gender, were calculated for Lambeth at two geographical levels (small and large neighbourhood level). The Poisson regression model predicting incidence rate ratios for schizophrenia using overall deprivation score was statistically significant at both levels after adjusting for ethnicity, ethnic density, population density and population turnover. The incidence rate ratio for electoral ward deprivation was 1.03 (95% CI=1.004-1.04) and for the super output area deprivation was 1.04 (95% CI=1.02-1.06). The individual domains of crime, employment deprivation and educational deprivation were statistically significant predictors of incidence but, after adjusting for the other domains as well as age, gender, ethnicity and population density, only crime and educational deprivation, remained statistically significant. Low income, poor housing and deprived living environment did not predict incidence.

CONCLUSIONS

In a highly urban area, an association was found between area-level deprivation and incidence of schizophrenia, after controlling for age, gender, ethnicity and population density; high crime and low levels of education accounted for this. As both of these are potentially modifiable, this suggests a possible means to reduce the incidence of schizophrenia.

Schizophrenia: an integrated sociodevelopmental-cognitive model

Schizophrenia remains a major burden on patients and society. The dopamine hypothesis attempts to explain the pathogenic mechanisms of the disorder, and the neurodevelopmental hypothesis the origins. In the past 10 years an alternative, the cognitive model, has gained popularity. However, the first two theories have not been satisfactorily integrated, and the most influential iteration of the cognitive model makes no mention of dopamine, neurodevelopment, or indeed the brain. In this Review we show that developmental alterations secondary to variant genes, early hazards to the brain, and childhood adversity sensitise the dopamine system, and result in excessive presynaptic dopamine synthesis and release. Social adversity biases the cognitive schema that the individual uses to interpret experiences towards paranoid interpretations. Subsequent stress results in dysregulated dopamine release, causing the misattribution of salience to stimuli, which are then misinterpreted by the biased cognitive processes. The resulting paranoia and hallucinations in turn cause further stress, and eventually repeated dopamine dysregulation hardwires the psychotic beliefs. Finally, we consider the implications of this model for understanding and treatment of schizophrenia.

The neurobiology of social environmental risk for schizophrenia: an evolving research field

INTRODUCTION

Schizophrenia is a severe and complex brain disorder that usually manifests in early adulthood and disturbs a wide range of human functions. More than 100 years after its initial description, the pathophysiology of the disorder is still incompletely understood. Many epidemiological studies strongly suggest a complex interaction between genetic and environmental risk factors for the development of the disorder. While there is considerable evidence for a social environmental component of this risk, the links between adverse social factors and altered brain function have just come into focus.

METHODS

In the present review, we first summarize epidemiological evidence for the significance of social environmental risk factors, outline the role of altered social stress processing in mental illness, and review the latest experimental evidence for the neural correlates of social environmental risk for schizophrenia.

CONCLUSIONS

The studies we have discussed in this review provide a selection of the current work in the field. We suggest that many of the social environmental risk factors may impact on perceived social stress and engage neural circuits in the brain whose functional and structural architecture undergoes detrimental change in response to prolonged exposure. We conclude that multidisciplinary approaches involving various fields and thoroughly constructed longitudinal designs are necessary to capture complex structure of social environmental risks.

Adversity, cannabis use and psychotic experiences: evidence of cumulative and synergistic effects

BACKGROUND

There is robust evidence that childhood adversity is associated with an increased risk of psychosis. There is, however, little research on intervening factors that might increase or decrease risk following childhood adversity.

AIMS

To investigate main effects of, and synergy between, childhood abuse and life events and cannabis use on odds of psychotic experiences.

METHOD

Data on psychotic experiences and childhood abuse, life events and cannabis use were collected from 1680 individuals as part of the South East London Community Health Study (SELCoH), a population-based household survey.

RESULTS

There was strong evidence that childhood abuse and number of life events combined synergistically to increase odds of psychotic experiences beyond the effects of each individually. There was similar, but weaker, evidence for cannabis use (past year).

CONCLUSIONS

Our findings are consistent with the hypothesis that childhood abuse creates an enduring vulnerability to psychosis that is realised in the event of exposure to further stressors and risk factors.

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

Schizophrenia is a devastating mental disorder. The level of risk in the general population is sustained by the persistence of social, environmental and biological factors, as well as their interactions. Socio-environmental risk factors for schizophrenia are well established and robust. The same can belatedly be said of genetic risk factors for the disorder. Recent progress in schizophrenia genetics is primarily fuelled by genome-wide association, which is able to leverage substantial proportions of additional explained variance previously classified as 'missing'. Here, we provide an outline of the emerging genetic landscape of schizophrenia and demonstrate how this knowledge can be turned into a simple empirical measure of genetic risk, known as a polygenic risk score. We highlight the statistical framework used to assess the clinical potential of the new score and finally, draw relevance to and discuss the clinical implications for the study of gene-environment interaction.

Migrants Examined for Determinants of psychopathology through INternet Assessment (MEDINA) study: a cross-sectional study among visitors of an Internet community

INTRODUCTION

Migration is a risk factor for the onset of psychopathology. A range of social factors may play a role in the aetiology of psychiatric disorders in migrants. A better understanding of these associations is needed to develop preventive interventions to reduce the disease burden in the migrant population. Research among minority groups is generally time consuming and it is difficult to recruit participants. Internet can offer interesting new possibilities to conduct research among ethnic minorities. This article describes the design of an epidemiological study in the Moroccan-Dutch population, which will be entirely performed online. We investigate the association between social factors and psychopathology.

METHODS AND ANALYSIS

The website Marokko.nl is visited by 70% of the young Moroccan-Dutch population in the Netherlands. This website therefore provides a unique possibility for research within this population. We will conduct a survey with online questionnaires via this website. The online survey consists of several validated short self-report questionnaires, measuring depressive and anxiety symptoms (The Kessler Psychological Distress Scale (K10)), psychotic symptoms (The Prodromal Questionnaire-16 (PQ-16)) and instruments measuring discrimination, social support and social defeat. Furthermore, demographic characteristics are collected. We will use univariate and multivariate methods for analysing the data.

ETHICS AND DISSEMINATION

The local medical ethical committee has assessed the study protocol and judged that the study could be conducted without their approval. Knowledge dissemination will take place through peer-reviewed publication in scientific journals as well as publication for participants on the project website.

DISCUSSION

In this study we further explore the association between psychopathology and social factors within an online Moroccan-Dutch sample. The recruitment of participants via the website Marokko.nl creates a big advantage in collecting a large sample of a specific migrant population. Strengths and limitations of the methodology are discussed. Furthermore, we review the advantages and challenges of online epidemiological research methods.

Modelling the interplay between childhood and adult adversity in pathways to psychosis: initial evidence from the AESOP study

BACKGROUND

There is evidence that a range of socio-environmental exposures is associated with an increased risk of psychosis. However, despite the fact that such factors probably combine in complex ways to increase risk, the majority of studies have tended to consider each exposure separately. In light of this, we sought to extend previous analyses of data from the AESOP (Aetiology and Ethnicity in Schizophrenia and Other Psychoses) study on childhood and adult markers of disadvantage to examine how they combine to increase risk of psychosis, testing both mediation (path) models and synergistic effects.

METHOD

All patients with a first episode of psychosis who made contact with psychiatric services in defined catchment areas in London and Nottingham, UK (n = 390) and a series of community controls (n = 391) were included in the AESOP study. Data relating to clinical and social variables, including parental separation and loss, education and adult disadvantage, were collected from cases and controls.

RESULTS

There was evidence that the effect of separation from, but not death of, a parent in childhood on risk of psychosis was partially mediated through subsequent poor educational attainment (no qualifications), adult social disadvantage and, to a lesser degree, low self-esteem. In addition, there was strong evidence that separation from, but not death of, a parent combined synergistically with subsequent disadvantage to increase risk. These effects held for all ethnic groups in the sample.

CONCLUSIONS

Exposure to childhood and adult disadvantage may combine in complex ways to push some individuals along a predominantly sociodevelopmental pathway to psychosis.

Childhood cognitive ability and its relationship with anxiety and depression in adolescence

BACKGROUND

Childhood cognitive ability may have protective effects against internalizing symptoms in adolescence, although this may depend on the time of symptom assessment and child gender. Also, the effects of childhood stressors on adolescent internalizing symptoms may be moderated by childhood cognitive ability.

METHODS

The sample included 4405 individuals from the Canadian National Longitudinal Study of Children and Youth (NLSCY). Between ages 4-5 and 10-11, children completed a test of verbal ability and scholastic aptitude and a series of mathematics computation tests. Internalizing symptoms were assessed via self-reports at ages 12-13 and 14-15.

RESULTS

Greater cognitive ability was generally associated with decreased odds of internalizing symptoms at age 12-13. However, greater cognitive ability generally increased, or had no effect on, the odds of internalizing symptoms at age 14-15. Some of the effects of childhood cognitive ability varied with child gender. Also, childhood cognitive ability attenuated the effects of family dysfunction and chronic illness throughout childhood on subsequent internalizing symptoms.

LIMITATIONS

These data are largely subject to some degree of reporting bias, the tests of cognitive ability are limited and may not represent overall cognitive ability, and there may be intermediary variables that account for the relationship between childhood cognitive ability and adolescent internalizing symptoms.

CONCLUSION

Results suggest that programs attempting to increase early cognitive skills may be particularly beneficial for girls. Also, an increased focus on cognitive skills may attenuate the negative effects of some stressors on subsequent anxious and depressive symptoms, regardless of child gender.

Sexual minority status and psychotic symptoms: findings from the Netherlands Mental Health Survey and Incidence Studies (NEMESIS)

BACKGROUND

Ethnic minority position is associated with increased risk for psychotic outcomes, which may be mediated by experiences of social exclusion, defeat and discrimination. Sexual minorities are subject to similar stressors. The aim of this study is to examine whether sexual minorities are at increased risk for psychotic symptoms and to explore mediating pathways.

METHOD

A cross-sectional survey was performed assessing cumulative incidence of psychotic symptoms with the Composite International Diagnostic Interview in two separate random general population samples (NEMESIS-1 and NEMESIS-2). Participants were sexually active and aged 18-64 years (n = 5927, n = 5308). Being lesbian, gay or bisexual (LGB) was defined as having sexual relations with at least one same-sex partner during the past year. Lifetime experience of any psychotic symptom was analysed using logistic regression, adjusted for gender, educational level, urbanicity, foreign-born parents, living without a partner, cannabis use and other drug use.

RESULTS

The rate of any psychotic symptom was elevated in the LGB population as compared with the heterosexual population both in NEMESIS-1 [odds ratio (OR) 2.56, 95% confidence interval (CI) 1.71-3.84] and NEMESIS-2 (OR 2.30, 95% CI 1.42-3.71). Childhood trauma, bullying and experience of discrimination partly mediated the association.

CONCLUSIONS

The finding that LGB orientation is associated with psychotic symptoms adds to the growing body of literature linking minority status with psychosis and other mental health problems, and suggests that exposure to minority stress represents an important mechanism.

At the crossroads of anthropology and epidemiology: current research in cultural psychiatry in the UK

Cultural psychiatry research in the UK comprises a broad range of diverse methodologies, academic disciplines, and subject areas. Methodologies range from epidemiological to anthropological/ethnographic to health services research; mixed methods research is becoming increasingly popular, as are public health and health promotional topics. After briefly outlining the history of cultural psychiatry in the UK we will discuss contemporary research. Prominent themes include: the epidemiology of schizophrenia among Africans/Afro-Caribbeans, migration and mental health, racism and mental health, cultural identity, pathways to care, explanatory models of mental illness, cultural competence, and the subjective experiences of healthcare provision among specific ethnic groups such as Bangladeshis and Pakistanis. Another strand of research that is attracting increasing academic attention focuses upon the relationship between religion, spirituality, and mental health, in particular, the phenomenology of religious experience and its mental health ramifications, as well as recent work examining the complex links between theology and psychiatry. The paper ends by appraising the contributions of British cultural psychiatrists to the discipline of cultural psychiatry and suggesting promising areas for future research.

The myth of schizophrenia as a progressive brain disease

Schizophrenia has historically been considered to be a deteriorating disease, a view reinforced by recent MRI findings of progressive brain tissue loss over the early years of illness. On the other hand, the notion that recovery from schizophrenia is possible is increasingly embraced by consumer and family groups. This review critically examines the evidence from longitudinal studies of (1) clinical outcomes, (2) MRI brain volumes, and (3) cognitive functioning. First, the evidence shows that although approximately 25% of people with schizophrenia have a poor long-term outcome, few of these show the incremental loss of function that is characteristic of neurodegenerative illnesses. Second, MRI studies demonstrate subtle developmental abnormalities at first onset of psychosis and then further decreases in brain tissue volumes; however, these latter decreases are explicable by the effects of antipsychotic medication, substance abuse, and other secondary factors. Third, while patients do show cognitive deficits compared with controls, cognitive functioning does not appear to deteriorate over time. The majority of people with schizophrenia have the potential to achieve long-term remission and functional recovery. The fact that some experience deterioration in functioning over time may reflect poor access, or adherence, to treatment, the effects of concurrent conditions, and social and financial impoverishment. Mental health professionals need to join with patients and their families in understanding that schizophrenia is not a malignant disease that inevitably deteriorates over time but rather one from which most people can achieve a substantial degree of recovery.

Prevalence of bullying victimisation amongst first-episode psychosis patients and unaffected controls

BACKGROUND

Despite increasing evidence suggesting that childhood maltreatment is significantly associated with psychosis, the specific role of bullying in the onset of psychotic disorders is still unclear. This study aimed to examine whether bullying was more prevalent amongst individuals presenting to services for the first time with a psychotic disorder than in unaffected community controls.

METHODS

Data on exposure to bullying, psychotic symptoms, cannabis use and history of conduct disorder were collected cross-sectionally from 222 first-presentation psychosis cases and 215 geographically-matched controls. Bullying victimisation was assessed retrospectively as part of the Brief Life Events schedule. Logistic regression was used to examine associations between exposure to bullying and case-control status, while controlling for potential confounders.

RESULTS

Psychosis cases were approximately twice as likely to report bullying victimisation when compared to controls. No significant interactions between bullying and either gender or cannabis use were found. Controls reporting being a victim of bullying were approximately twice as likely to also report at least one psychosis-like symptom.

CONCLUSIONS

Our results extend previous research by suggesting that bullying victimisation may contribute to vulnerability to develop a psychotic disorder in some individuals.

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.

Acculturative stress and psychotic-like experiences among Asian and Latino immigrants to the United States

Previous studies have shown variation in the prevalence and incidence of psychosis across immigrant groups, but the underlying mechanisms are not fully understood. Stress related to acculturation may increase risk for psychosis among immigrant groups. In this study we examine the association between acculturative stress and psychotic-like experiences in a sample of Latino- and Asian-American immigrants to the United States in the National Latino and Asian American Study (n=2434). Acculturative stress was associated with visual and auditory hallucinations among Asians, but only with hearing voices among Latinos. Increased risk for psychotic-like experiences among Latinos was primarily associated with younger age of immigration. Acculturative stress appears to be a promising candidate mechanism explaining the relationship between immigration and psychosis, particularly among Asian Americans. Ethnic differences may reflect variability between groups that integrate more readily into the host culture and those that are subject to greater discrimination and environmental adversity.

The association between adult attachment style and delusional-like experiences in a community sample of women

Community-based surveys have found that many otherwise well individuals endorse delusional-like experiences (DLEs). There is extensive literature that describes the demographic and psychosocial correlates of DLE; however, we know little about the association between DLE and attachment style. The association between DLEs (assessed by the Peters Delusional Inventory [PDI]) and interpersonal relationship style (as assessed by the Adult Attachment Questionnaire and the Dyadic Adjustment Scale) was examined in 3360 women. When adjusted for the presence of depressive and anxiety symptoms, high scores on the PDI (lowest versus highest quartiles) were associated with a) difficulties in adult attachment style particularly in the discomfort with closeness and preoccupation with relationships subscales and b) conflictual dyadic adjustment (adjusted odds ratios and 95% confidence intervals, 2.43 and 1.94-3.04, 2.50 and 1.99-3.14, and 2.90 and 1.38-6.06, respectively). The association between adult attachment style and DLE provides new clues into the causal pathway underpinning these common experiences.

Increased prevalence of psychotic disorders among third-generation migrants: results from the French Mental Health in General Population survey

There is very strong evidence that the prevalence of psychosis is elevated in migrant populations and that this risk persists into the second generation. However, these results have not been replicated in France, and the prevalence of psychotic disorders in the third generation of migrants remains unknown. Based on the Mental Health in General Population survey (n=37063), we report for the first time the increased prevalence of psychotic disorders in migrants in France, which persists into the second generation for a single psychotic episode (SPE) (OR=1.43, 95% CI [1.02-2.03], p<0.03) and into the third generation for recurrent psychotic disorder (RPD) (OR=1.78, 95% CI [1.45-2.18], p<0.0001) after adjustment for age, sex, level of education and cannabis use. Complementary statistical analyses of our sample showed a significantly higher risk of SPE in migrants from the French West Indies and Africa (χ(2)=17.70, p<0.01). These results are consistent with the socio-developmental model and the psychosis continuum hypothesis.

Social networks, support and early psychosis: a systematic review

Background. There is strong evidence that those with a long-standing psychotic disorder have fewer social contacts and less social support than comparison groups. There is less research on the extent of social contacts and support prior to or at the onset of psychosis. In the light of recent evidence implicating a range of social experiences and contexts at the onset of psychosis, it is relevant to establish whether social networks and support diminished before or at the time of onset and whether the absence of such supports might contribute to risk, either directly or indirectly. We, therefore, conducted a systematic review of this literature to establish what is currently known about the relationship between social networks, support and early psychosis. Methods. We identified all studies investigating social networks and support in first episode psychosis samples and in general population samples with measures of psychotic experiences or schizotype by conducting systematic searches of electronic databases using pre-defined search terms and criteria. Findings were synthesized using non-quantitative approaches. Results. Thirty-eight papers were identified that met inclusion criteria. There was marked methodological heterogeneity, which limits the capacity to draw direct comparisons. Nonetheless, the existing literature suggests social networks (particularly close friends) and support diminished both among first episode samples and among non-clinical samples reporting psychotic experiences or with schizotype traits, compared with varying comparison groups. These differences may be more marked for men and for those from minority ethnic populations. Conclusions. Tentatively, reduced social networks and support appear to pre-date onset of psychotic disorder. However, the substantial methodological heterogeneity among the existing studies makes comparisons difficult and suggests a need for more robust and comparable studies on networks, support and early psychosis.

Ethnic minority position and risk for psychotic disorders

PURPOSE OF REVIEW

This article reviews the recent literature about migration, ethnic minority position and the risk of psychotic disorders.

RECENT FINDINGS

A meta-analysis found that both first and second-generation migrants have on average a two-fold increase in risk for psychotic disorders. In the Netherlands, the risk was most elevated for individuals who migrated in early childhood. Several studies investigated diagnostic ethnic bias and reported greater likelihood of schizophrenia diagnosis in ethnic minority patients at the cost of diagnosis of affective psychotic disorders. Neighbourhood ethnic density was related to prevalence of psychotic experiences in ethnic minority populations in the UK. Perceived discrimination was associated with severity of psychotic and depressive symptoms in ethnic minority patients. Both weak and strong ethnic identification, as well as experiences of social adversity, were related to risk for psychosis. Low neonatal vitamin D was associated with adult risk for psychosis and vitamin D levels in childhood were associated with nonclinical psychotic experiences.

SUMMARY

The risk for psychotic disorders is increased among ethnic minority populations. Experiences of social adversity and having a disadvantaged outsider status may explain the excess risk. More research is needed into potential biological mechanisms, including vitamin D.

Adolescent stress-induced epigenetic control of dopaminergic neurons via glucocorticoids

Environmental stressors during childhood and adolescence influence postnatal brain maturation and human behavioral patterns in adulthood. Accordingly, excess stressors result in adult-onset neuropsychiatric disorders. We describe an underlying mechanism in which glucocorticoids link adolescent stressors to epigenetic controls in neurons. In a mouse model of this phenomenon, a mild isolation stress affects the mesocortical projection of dopaminergic neurons in which DNA hypermethylation of the tyrosine hydroxylase gene is elicited, but only when combined with a relevant genetic risk for neuropsychiatric disorders. These molecular changes are associated with several neurochemical and behavioral deficits that occur in this mouse model, all of which are blocked by a glucocorticoid receptor antagonist. The biology and phenotypes of the mouse models resemble those of psychotic depression, a common and debilitating psychiatric disease.

Perceived discrimination, a risk factor for developing psychoses in Romanian emigrants?

AIM

Investigating the relationship between the perceived discrimination and the psychotic symptom severity as well as the level of social functioning in Romanian migrants with psychotic disorders, considering that this is a major stressor which contributes to the feeling of alienation from the majority culture.

MATERIALS AND METHODS

The assessment included 70 patients admitted to the Cluj Psychiatric Hospital, from January 2007 to April 2010, diagnosed with acute psychotic disorder, schizophrenia and other schizophrenia-spectrum disorders, according to ICD 10 diagnosis criteria. The patients completed the migration questionnaire for socio-demographic variables and the level of discrimination perceived, the psychotic symptom severity being assessed through PANNS and GAF scales.

RESULTS

The level of discrimination perceived by the subjects correlated neither with PANNS symptoms (r=-0.051, p>0.05) nor with the social functioning level (r=0.029, p>0.05). The social functioning level had significant negative correlations with the PANNS level of general symptoms(r=-0.41, p>0.05). There are no differences between PANNS symptoms, social functioning and perceived discrimination according to age, gender or illness onset country. There are significantly statistical differences between education categories concerning the general symptoms on PANNS scale, respectively the level of discrimination perceived, the lower level of education being associated with a highly perceived discrimination level. The subjects of rural origin perceived discrimination at a higher level than those from urban area (t=2.31, p<0.05).

CONCLUSIONS

Discrimination is perceived more intensely by the subjects from the rural area and with a poorer educational level but this doesn't correlate with psychotic symptom severity.

Childhood trauma as a cause of psychosis: linking genes, psychology, and biology

Recent studies have provided robust evidence for an association between childhood trauma (CT) and psychosis. Meta-analyses have quantified the association, pointing to odds ratios in the order of around 3, and prospective studies have shown that reverse causation is unlikely to explain the association. However, more work is needed to address the possibility of a gene-environment correlation, that is, whether genetic risk for psychosis predicts exposure to CT. Nevertheless, multiple studies have convincingly shown that the association between CT and psychosis remains strong and significant when controlling for genetic risk, in agreement with a possible causal association. In addition, several studies have shown plausible psychological and neurobiological mechanisms linking adverse experiences to psychosis, including induction of social defeat and reduced self-value, sensitization of the mesolimbic dopamine system, changes in the stress and immune system, and concomitant changes in stress-related brain structures, such as the hippocampus and the amygdala, findings that should be integrated, however, in more complex models of vulnerability. It is currently unclear whether genetic vulnerability plays a role in conferring the mental consequences of adversity, and which genes are likely to be involved. The current, limited evidence points to genes that are not specifically involved in psychosis but more generally in regulating mood (serotonin transporter gene), neuroplasticity (brain-derived neurotrophic factor), and the stress-response system (FKBP5), in line with a general effect of CT on a range of mental disorders, rather than suggesting specificity for psychosis.

[Environmental risk factors for schizophrenia: a review]

BACKGROUND

Evidence of variations in schizophrenia incidence rates has been found in genetically homogenous populations, depending on changes within time or space of certain environmental characteristics. The consideration of the impact of environmental risk factors in etiopathogenic studies has put the environment in the forefront of research regarding psychotic illnesses. Various environmental factors such as urbanicity, migration, cannabis, childhood traumas, infectious agents, obstetrical complications and psychosocial factors have been associated with the risk of developing schizophrenia. These risk factors can be biological, physical, psychological as well as social and may operate at different times in an individual's life (fetal period, childhood, adolescence and early adulthood). Whilst some of these factors act on an individual level, others act on a populational level, modulating the individual risk. These factors can have a direct action on the development of schizophrenia, or on the other hand act as markers for directly implicated factors that have not yet been identified.

LITERATURE FINDINGS

This article summarizes the current knowledge on this subject. An extensive literature search was conducted via the search engine Pubmed. Eight risk factors were selected and developed in the following paper: urbanicity (or living in an urban area), cannabis, migration (and ethnic density), obstetrical complications, seasonality of birth, infectious agents (and inflammatory responses), socio-demographic factors and childhood traumas. For each of these factors, we provide information on the importance of the risk, the vulnerability period, hypotheses made on the possible mechanisms behind the factors and the level of proof the current research offers (good, medium, or insufficient) according to the amount, type, quality and concordance of the studies at hand. Some factors, such as cannabis, are "unique" in their influence on the development of schizophrenia since it labels only one risk factor. Others, such as obstetrical complications, are grouped (or "composed") in that they include various sub-factors that can influence the development of schizophrenia.

DISCUSSION

The data reviewed clearly demonstrates that environmental factors have an influence on the risk of developing schizophrenia. For certain factors - cannabis, migration, urbanicity, obstetrical complications, seasonality - there is enough evidence to establish an association with the risk of schizophrenia. This association, however, remains weak (especially for seasonality). With the exception of cannabis, no direct link can yet be established. Concerning the three remaining factors - childhood traumas, infectious agents, socio-demographic factors - the available proof is insufficient. One main limitation concerning all environmental factors is the generalization of results due to the fact that the studies were conducted on geographically limited populations. The current state of knowledge does not allow us to determine the mechanisms by which these factors may act.

CONCLUSION

Further research is needed to fill the gaps in our understanding of the subject. In response to this need, a collaborative European project (European Study of Gene-Environment Interactions [EU GEI]) was set-up. This study proposes the analysis of those environmental factors that influence the incidence of schizophrenia in various European countries, in both rural and urban settings, migrant and native populations, as well as their interaction with genetic factors.

Cortical circuit dysfunction and cognitive deficits in schizophrenia--implications for preemptive interventions

Schizophrenia is a devastating disorder that is common, usually chronic, frequently associated with substantial co-morbidity for addictive and medical disorders and, as a consequence, very costly in both personal and economic terms. At present, no proven means for preventing or modifying the course of the illness exist. This review discusses evidence supporting the ideas that: (i) impairments in certain cognitive processes are the core feature of schizophrenia; (ii) these cognitive impairments reflect abnormalities in specific cortical circuits; and (iii) these circuitry abnormalities arise during childhood-adolescence. The implications of these findings for the development and implementation of safe, preemptive, disease-modifying interventions in individuals at high risk for a clinical diagnosis of schizophrenia are considered.

First-episode psychosis at the West Bologna Community Mental Health Centre: results of an 8-year prospective study

BACKGROUND

Research mostly conducted in the UK and northern Europe has established that there are high rates of first-episode psychosis (FEP) in large cities and immigrant populations; moreover, psychosis has been found to be associated with cannabis use and early trauma. The present study aimed to evaluate the incidence rate of FEP and the distribution of several risk factors (e.g. age, ethnicity, substance abuse) in Bologna, Italy.

METHOD

The Bologna FEP (BoFEP) study is an 8-year prospective study. All FEP patients, 18-64 years old, consecutively referred to the West Bologna Community Mental Health Centre (CMHC) from 2002 to 2009 were evaluated. Sociodemographic information, migration history and clinical data were collected through an ad-hoc schedule. Psychiatric diagnoses were recorded using the Schedule for Clinical Assessment of Neuropsychiatry (SCAN).

RESULTS

The overall incidence rate (IR) in the BoFEP study was 16.4 per 100 000 person-years [95% confidence interval (CI) 13.9-18.9]. The incidence was higher in young people, men and migrants (MI).

CONCLUSIONS

The IR of FEP found by the Bologna study is lower than that found by other European studies. However, as in other studies, the incidence was higher in certain groups. This heterogeneity has implications for policy and mental health service development, and for understanding the aetiology of psychosis.

Ethnic density as a buffer for psychotic experiences: findings from a national survey (EMPIRIC)

BACKGROUND

Aetiological mechanisms underlying ethnic density associations with psychosis remain unclear.

AIMS

To assess potential mechanisms underlying the observation that minority ethnic groups experience an increased risk of psychosis when living in neighbourhoods of lower own-group density.

METHOD

Multilevel analysis of nationally representative community-level data (from the Ethnic Minorities Psychiatric Illness Rates in the Community survey), which included the main minority ethnic groups living in England, and a White British group. Structured instruments assessed discrimination, chronic strains and social support. The Psychosis Screening Questionnaire ascertained psychotic experiences.

RESULTS

For every ten percentage point reduction in own-group density, the relative odds of reporting psychotic experiences increased 1.07 times (95% CI 1.01-1.14, P = 0.03 (trend)) for the total minority ethnic sample. In general, people living in areas of lower own-group density experienced greater social adversity that was in turn associated with reporting psychotic experiences.

CONCLUSIONS

People resident in neighbourhoods of higher own-group density experience 'buffering' effects from the social risk factors for psychosis.

The 3rd Schizophrenia International Research Society Conference, 14-18 April 2012, Florence, Italy: summaries of oral sessions

The 3rd Schizophrenia International Research Society Conference was held in Florence, Italy, April 14-18, 2012 and this year had as its emphasis, "The Globalization of Research". Student travel awardees served as rapporteurs for each oral session and focused their summaries on the most significant findings that emerged and the discussions that followed. The following report is a composite of these summaries. We hope that it will provide an overview for those who were present, but could not participate in all sessions, and those who did not have the opportunity to attend, but who would be interested in an update on current investigations ongoing in the field of schizophrenia research.

Genetic Risk and Outcome of Psychosis (GROUP), a multi-site longitudinal cohort study focused on gene-environment interaction: objectives, sample characteristics, recruitment and assessment methods

OBJECTIVE

A longitudinal focus on gene-environment vulnerability and resilience in both patients, their unaffected family members and non-related controls offers the opportunity to elucidate etiological and pathogenetic factors influencing the onset and course of psychotic disorders. The current paper delineates the objectives, sample characteristics, recruitment and assessment procedures of the Genetic Risk and Outcome of Psychoses (GROUP) study.

METHODS

A naturalistic longitudinal cohort study with assessments at baseline, after three and six years of follow-up. The study is conducted by a consortium of four university psychiatric centres, with their affiliated mental health care institutions in the Netherlands covering more than 7.5 million inhabitants. Extensive assessment of genetic factors, environmental factors, (endo)phenotypes, and outcome.

RESULTS

At baseline, 1120 patients, 1057 siblings, 919 parents and 590 healthy controls were included.

CONCLUSION

The GROUP study will contribute to insight in risk and protective factors in the aetiology of non-affective psychotic disorders, and in the variation in their course and outcome.

Migration and autism spectrum disorder: population-based study

BACKGROUND

Migration has been implicated as a risk factor for autism, but evidence is limited and inconsistent.

AIMS

To investigate the relationship between parental migration status and risk of autism spectrum disorder, taking into consideration the importance of region of origin, timing of migration and possible discrepancies in associations between autism subtypes.

METHOD

Record-linkage study within the total child population of Stockholm County between 2001 and 2007. Individuals with high- and low-functioning autism were defined as having autism spectrum disorder with and without comorbid intellectual disability, and ascertained via health and habilitation service registers.

RESULTS

In total, 4952 individuals with autism spectrum disorder were identified, comprising 2855 children with high-functioning autism and 2097 children with low-functioning autism. Children of migrant parents were at increased risk of low-functioning autism (odds ratio (OR) = 1.5, 95% CI 1.3-1.7); this risk was highest when parents migrated from regions with a low human development index, and peaked when migration occurred around pregnancy (OR = 2.3, 95% CI 1.7-3.0). A decreased risk of high-functioning autism was observed in children of migrant parents, regardless of area of origin or timing of migration. Parental age, income or obstetric complications did not fully explain any of these associations.

CONCLUSIONS

Environmental factors associated with migration may contribute to the development of autism presenting with comorbid intellectual disability, especially when acting in utero. High- and low-functioning autism may have partly different aetiologies, and should be studied separately.

Psychosis and suicide risk by ethnic origin and history of migration in the Netherlands

BACKGROUND

There is an increased incidence of non-affective psychotic disorders (NAPD) among first- and second-generation migrants in Europe. The purpose of this population-based study was to compare the risk of suicide in Dutch natives and immigrants with or without NAPD.

METHODS

Cases of NAPD (n=12 580) from three Dutch psychiatric registers were linked to the cause of death register of Statistics Netherlands and were compared to matched controls (n=244 792) from the population register, who had no such diagnosis. Hazard ratios (HRs) of suicide were estimated and adjusted for age and gender by Cox regression analysis.

RESULTS

The presence of NAPD was strongly associated with suicide risk in each ethnic group. However, for all ethnic minority groups the HRs were somewhat lower than among Dutch natives, for whom the HR was 23.4 (95%-CI; 18.5-29.7). A closer examination revealed that suicide risk was influenced by the history of migration. While the risk for immigrants of the first generation, diagnosed with NAPD, was significantly lower than that for native Dutch patients (HR=0.45; 95%-CI: 0.28-0.73), the risk for those of the second generation was more similar to that for the Dutch (HR=0.85; 95%-CI: 0.51-1.40) (P value of history of migration=0.005).

CONCLUSION

Immigrants diagnosed with NAPD of the first generation appear to be protected against suicide, whereas this protection is waning among those of the second generation. This is the first study worldwide on suicide in migrants with NAPD and the first study of suicide in patients with NAPD in the Netherlands.

Comparing the clinical presentation of first-episode psychosis across different migrant and ethnic minority groups in Montreal, Quebec

OBJECTIVE

To explore differences in severity and nature of symptoms of first-episode psychosis (FEP) according to ethnic group and migrant status.

METHOD

We administered rating scales to assess positive and negative symptoms, as well as general psychopathology, to 301 consecutive patients presenting with an FEP within a defined catchment area in Montreal, Quebec, classified according to ethnicity and migrant status. Symptom scores of Euro-Canadian patients without a recent history of migration, that is, the reference group (n = 145), were compared with those of African and Afro-Caribbean (n = 39), Asian (n = 27), Central and South American (n = 15), Middle Eastern and North African (n = 24), and European and North American (n = 39) patients.

RESULTS

Except for referral source, there were no significant differences between ethnic groups on any demographic variables. The African and Afro-Caribbean group had a higher level of negative symptoms (especially alogia) and general psychopathology scores on the Positive and Negative Syndrome Scale (especially, uncooperativeness, preoccupation, and poor attention), compared with the reference group. Ethnic groups did not differ on the Scale for the Assessment of Positive Symptoms scores.

CONCLUSIONS

A comparison of FEP patients from different ethnic groups and native-born Euro-Canadians revealed no significant differences in the nature of positive symptoms at first presentation or in age at onset, suggesting that there was no evidence for the hypothesis that ethnic minorities are misdiagnosed as psychotic. Increased severity of negative symptoms and general psychopathology, specifically among the black ethnic minority group, may have implications for the role of ethnicity for the treatment and outcome of the initial episode of psychotic disorders.

Dendritic spine pathology in schizophrenia

Schizophrenia is a neurodevelopmental disorder whose clinical features include impairments in perception, cognition and motivation. These impairments reflect alterations in neuronal circuitry within and across multiple brain regions that are due, at least in part, to deficits in dendritic spines, the site of most excitatory synaptic connections. Dendritic spine alterations have been identified in multiple brain regions in schizophrenia, but are best characterized in layer 3 of the neocortex, where pyramidal cell spine density is lower. These spine deficits appear to arise during development, and thus are likely the result of disturbances in the molecular mechanisms that underlie spine formation, pruning, and/or maintenance. Each of these mechanisms may provide insight into novel therapeutic targets for preventing or repairing the alterations in neural circuitry that mediate the debilitating symptoms of schizophrenia.

Ethnicity and baseline symptomatology in patients with an At Risk Mental State for psychosis

BACKGROUND

Ethnicity has been associated with different incidence rates and different symptom profiles in young patients with psychotic-like disorders. No studies so far have examined the effect of ethnicity on symptoms in people with an At Risk Mental State (ARMS).

METHOD

In this cross-sectional study, we analysed the relationship between ethnicity and baseline data on the severity of psychopathology scores in 201 help-seeking patients who met the ARMS criteria and agreed to participate in the Dutch Early Detection and Intervention (EDIE-NL) trial. Eighty-seven of these patients had a non-Dutch ethnicity. We explored the possible mediating role of ethnic identity.

RESULTS

Higher rates of negative symptoms, and of anhedonia in particular, were found in the ethnic minority group. This result could be attributed mainly to the Moroccan-Dutch and Turkish-Dutch subgroups, who also presented with more depression symptoms when the groups were examined separately. The ethnic minority group displayed a lower level of ethnic group identity compared to the immigrants of the International Comparative Study of Ethnocultural Youth (ICSEY). Ethnic identity was inversely related to symptoms in the Moroccan-Dutch patient group.

CONCLUSIONS

The prevalence of more severe negative symptoms and depression symptoms in ethnic minority groups deserves more attention, as the experience of attenuated positive symptoms when accompanied by negative symptoms or distress has proven to be predictive for transition to a first psychotic episode.

Epigenetic epidemiology in psychiatry: A translational neuroscience perspective

Accumulating evidence from the field of neuroscience indicates a crucial role for epigenetic regulation of gene expression in development and aging of nervous system and suggests that aberrations in the epigenetic machinery are involved in the etiology of psychiatric disorders. Epidemiologic evidence on epigenetics in psychiatry, however, is currently very sparsely available, but is consistent with a mediating role for epigenetic mechanisms in bringing together inherited and acquired risk factors into a neurodevelopmental etiological model of psychiatric disorders. Here, we review evidence from the epidemiological and neuroscience literature, and aim to converge the evidence into an etiological model of psychiatric disorders that encompasses environmental, genetic and epigenetic contributions. Given the dynamic nature of the epigenetic machinery and the potential reversibility of epigenetic modifications, future well-designed interdisciplinary and translational studies will be of key importance in order to identify new targets for prevention and therapeutic strategies.

Socio-economic disadvantage and delusional-like experiences: a nationwide population-based study

PURPOSE

Delusional-like experiences (DLE) have been associated with low income, suggesting that more broadly defined socio-economic disadvantage may be associated with these experiences. We had the opportunity to explore the association between DLE and both individual- and area-level measures of socio-economic disadvantage.

METHOD

Subjects were drawn from the Australian National Survey of Mental Health and Wellbeing 2007. The Composite International Diagnostic Interview was used to identify DLE, common psychiatric disorders, and physical disorders. Individual-level and area-level socio-economic disadvantage measures were available based on variables including income, educational attainment, employment status, and housing. We examined the relationship between the variables of interest using logistic regression, adjusting for potential confounding factors.

RESULTS

Of the 8773 subjects, 8.4% (n=776) positively endorsed one or more DLE. DLE screen items were more likely to be endorsed by those who were (a) younger, (b) never married, or widowed, separated or divorced status, (c) migrants, or (d) living in rented houses. There were significant associations between socio-economic disadvantage and increased DLE endorsement, and this was found for both individual-level and area-level measures of socio-economic disadvantage. In general, the associations remained significant after adjusting for a range of potential confounding factors and in planned sensitivity analyses.

CONCLUSIONS

DLE are associated with socio-economic disadvantage in the general population. We speculate that the link between socio-economic disadvantage and DLE may be mediated by psychosocial stress and general psychological distress.

The influence of immigrant status and concentration on psychiatric disorder in Canada: a multi-level analysis

BACKGROUND

Many studies have reported an increased incidence of psychiatric disorder (particularly psychotic disorders) among first generation adult immigrants, along with an increasing risk for ethnic minorities living in low-minority concentration neighborhoods. These studies have depended mostly on European case-based databases. In contrast, North American studies have suggested a lower risk for psychiatric disorder in immigrants, although the effect of neighborhood immigrant concentration has not been studied extensively.

METHOD

Using multi-level modeling to disaggregate individual from area-level influences, this study examines the influence of first generation immigrant status at the individual level, immigrant concentration at the neighborhood-level and their combined effect on 12-month prevalence of mood, anxiety and substance-dependence disorders and lifetime prevalence of psychotic disorder, among Canadians.

RESULTS

Individual-level data came from the Canadian Community Health Survey (CCHS) 1.2, a cross-sectional study of psychiatric disorder among Canadians over the age of 15 years; the sample for analysis was n=35,708. The CCHS data were linked with neighborhood-level data from the Canadian Census 2001 for multi-level logistic regression. Immigrant status was associated with a lower prevalence of psychiatric disorder, with an added protective effect for immigrants living in neighborhoods with higher immigrant concentrations. Immigrant concentration was not associated with elevated prevalence of psychiatric disorder among non-immigrants.

CONCLUSIONS

The finding of lower 12-month prevalence of psychiatric disorder in Canadian immigrants, with further lessening as the neighborhood immigrant concentration increases, reflects a model of person-environment fit, highlighting the importance of studying individual risk factors within environmental contexts.

Integrative etiopathogenetic models of psychotic disorders: methods, evidence and concepts

Integrative models of the etiopathogesnesis of psychotic disorders are needed since a wealth of information from such diverse fields as neurobiology, psychology, and the social sciences is currently changing the concepts of mental disorders. Several approaches to integrate these streams of information into coherent concepts of psychosis are feasible and will need to be assessed in future experimental studies. Common to these concepts are the notion of psychotic disorders as brain disorders and a polythetic approach in that it is increasingly realized that a multitude of interindividually partially different pathogenetic factors interact in individual persons in a complex fashion resulting in the clinical symptoms of psychosis.

First-generation immigrants and hospital admission rates for psychosis and affective disorders: an ecological study in Ontario

OBJECTIVE

The immigrant population in Canada, and particularly in Ontario, is increasing. Our ecological study first assessed if there was an association between areas with proportions of first-generation immigrations and admissions rates for psychotic and affective disorders. Second, this study examined if area-level risks would persist after controlling for area socioeconomic factors in census-derived geographical areas-Forward Sortation Areas (FSAs)-in Ontario.

METHODS

Ontario's inpatient admission records from 1996 to 2005 and census data from 2001 were analyzed to derive FSA rates of first admissions for psychotic disorders and affective disorders per 100 000 person-years. Negative binomial regression models were adjusted, first, for FSA age and sex and, second, also for FSA population density and average income.

RESULTS

Using age- and sex-adjusted models, admission rates for psychotic disorders were higher in areas with greater proportions of immigrants. These areas were associated with lower admission rates for affective disorders. When FSA average income and population density were added to the models, the influence of immigrants was attenuated to nonsignificant levels in models predicting psychotic disorders admission rates. However, greater proportions of immigrants remained significantly protective when predicting rates of affective disorders.

DISCUSSION

Our study provides insight about the influence of area-level variables on risk of admission for psychotic and affective disorders in high immigrant areas. There is a dearth of current Canadian research on immigrant admission for psychotic disorders at the individual or area level. Future area- and individual-level studies may better identify groups at risk and possible explanations.

The environment and schizophrenia

Psychotic syndromes can be understood as disorders of adaptation to social context. Although heritability is often emphasized, onset is associated with environmental factors such as early life adversity, growing up in an urban environment, minority group position and cannabis use, suggesting that exposure may have an impact on the developing 'social' brain during sensitive periods. Therefore heritability, as an index of genetic influence, may be of limited explanatory power unless viewed in the context of interaction with social effects. Longitudinal research is needed to uncover gene-environment interplay that determines how expression of vulnerability in the general population may give rise to more severe psychopathology.