Review: the wider social environment and schizophrenia

Conceptualization and characterization of "primary" and "secondary" cognitive impairment in schizophrenia

Cognitive impairment represents one of the core features of schizophrenia, involves both neurocognition and social cognition domains, and has a significant negative impact on real-world functioning. The present review provides a framework for the conceptualization and characterization of "primary" and "secondary" cognitive impairment in schizophrenia. In this conceptualization, primary cognitive impairment can be defined as a consequence of the neurobiological alterations that underlie psychopathological manifestations of the disorder, while secondary cognitive impairment can be defined as the results of a source issue that has a negative impact on cognitive performance. Sources of secondary cognitive impairment are frequent in people with schizophrenia and include several different factors, such as positive and negative symptoms, depressive symptoms, autistic symptoms, pharmacotherapy, substance abuse, metabolic syndrome, social deprivation, and sleep disorders. It can be hypothesized that secondary cognitive impairment may be improved by effectively resolving the source issue, while primary cognitive impairment may benefit from dedicated treatment. Further research is required to confirm this hypothesis, to better characterize the distinction between primary and secondary cognitive impairment in a clinical and in a neurobiological perspective, and to evaluate the impact of systematically assessing and treating secondary cognitive impairment.

Changing Neighborhood Income Deprivation Over Time, Moving in Childhood, and Adult Risk of Depression

Importance

Complex biological, socioeconomic, and psychological variables combine to cause mental illnesses, with mounting evidence that early-life experiences are associated with adulthood mental health.

Objective

To evaluate whether changing neighborhood income deprivation and residential moves during childhood are associated with the risk of receiving a diagnosis of depression in adulthood.

Design, Setting, and Participants

This cohort study included the whole population of 1 096 916 people born in Denmark from January 1, 1982, to December 31, 2003, who resided in the country during their first 15 years of life. Individuals were followed up from 15 years of age until either death, emigration, depression diagnosis, or December 31, 2018. Longitudinal data on residential location was obtained by linking all individuals to the Danish longitudinal population register. Statistical analysis was performed from June 2022 to January 2024.

Exposures

Exposures included a neighborhood income deprivation index at place of residence for each year from birth to 15 years of age and a mean income deprivation index for the entire childhood (aged ≤15 years). Residential moves were considered by defining "stayers" as individuals who lived in the same data zone during their entire childhood and "movers" as those who did not.

Main Outcomes and Measures

Multilevel survival analysis determined associations between neighborhood-level income deprivation and depression incidence rates after adjustment for individual factors. Results were reported as incidence rate ratios (IRRs) with 95% credible intervals (95% CrIs). The hypotheses were formulated before data collection.

Results

A total of 1 096 916 individuals (563 864 male participants [51.4%]) were followed up from 15 years of age. During follow-up, 35 098 individuals (23 728 female participants [67.6%]) received a diagnosis of depression. People living in deprived areas during childhood had an increased risk of depression (IRR, 1.10 [95% CrI, 1.08-1.12]). After full individual-level adjustment, the risk was attenuated (IRR, 1.02 [95% CrI, 1.01-1.04]), indicating an increase of 2% in depression incidence for each 1-SD increase in income deprivation. Moving during childhood, independent of neighborhood deprivation status, was associated with significantly higher rates of depression in adulthood compared with not moving (IRR, 1.61 [95% CrI, 1.52-1.70] for 2 or more moves after full adjustment).

Conclusions and Relevance

This study suggests that, rather than just high or changing neighborhood income deprivation trajectories in childhood being associated with adulthood depression, a settled home environment in childhood may have a protective association against depression. Policies that enable and support settled childhoods should be promoted.

A Global, Regional, and National Burden and Quality of Care Index for Schizophrenia: Global Burden of Disease Systematic Analysis 1990-2019

BACKGROUND AND HYPOTHESIS

Schizophrenia is a mental disorder usually presented in adulthood that affects roughly 0.3 percent of the population. The disease contributes to more than 13 million years lived with disability the global burden of disease. The current study aimed to provide new insights into the quality of care in Schizophrenia via the implementation of the newly introduced quality of care index (QCI) into the existing data.

STUDY DESIGN

The data from the global burden of disease database was used for schizophrenia. Two secondary indices were calculated from the available indices and used in a principal component analysis to develop a proxy of QCI for each country. The QCI was then compared between different sociodemographic index (SDI) and ages. To assess the disparity in QCI between the sexes, the gender disparity ratio (GDR) was also calculated and analyzed in different ages and SDIs.

STUDY RESULTS

The global QCI proxy score has improved between 1990 and 2019 by roughly 13.5%. Concerning the gender disparity, along with a rise in overall GDR the number of countries having a GDR score of around one has decreased which indicates an increase in gender disparity regarding quality of care of schizophrenia. Bhutan and Singapore had 2 of the highest QCIs in 2019 while also showing GDR scores close to one.

CONCLUSIONS

While the overall conditions in the quality of care have improved, significant disparities and differences still exist between different countries, genders, and ages in the quality of care regarding schizophrenia.

Responding to the Heat and Planning for the Future: An Interview-Based Inquiry of People with Schizophrenia Who Experienced the 2021 Heat Dome in Canada

People with schizophrenia have died at disproportionately higher rates during recent extreme heat events (EHEs) in Canada, including the deadly 2021 Heat Dome in British Columbia (B.C.). However, to date, little research has qualitatively focused on how people with schizophrenia experience and respond to EHEs. This study aimed to (i) explore how people with schizophrenia experienced and were impacted by the 2021 Heat Dome physically, cognitively, and emotionally and (ii) understand their level of awareness and health-protective actions taken in response to the EHE. Between October 2023 and February 2024, interviews were conducted with 35 people with schizophrenia who experienced the 2021 Heat Dome in a community setting within B.C., Canada. The semi-structured interviews were guided by pre-defined questions to explore the participant's background, living situation, social network, awareness and access to heat-mitigation measures. The transcripts were analyzed using a descriptive form of thematic analysis. Participants shared critical insights on how the EHE impacted them, including descriptions of mild to severe physical manifestations of heat stress (e.g., fainting, heat rashes), the triggering of schizophrenia-related symptoms (e.g., paranoia, hallucinations), and the detrimental effects on their energy levels and emotional stability, which further caused disruptions to their everyday life. Participants also illustrated gaps in knowledge and challenges experienced with accessing information, which hindered their ability to manage the heat exposure effectively and, for some, resulted in no actions (or counter-intuitive actions) being taken to mitigate the heat. These findings demonstrate the complex ways that individuals with schizophrenia experienced and responded to the 2021 Heat Dome and revealed various situational and contextual factors that further compounded the challenge of heat mitigation. These findings can support the development of tailored individual and community-level heat response and communication initiatives and strategies for people with schizophrenia.

The association between neighborhood-level social fragmentation and distressing psychotic-like experiences in early adolescence: the moderating role of close friends

BACKGROUND

Early exposure to neighborhood social fragmentation has been shown to be associated with schizophrenia. The impact of social fragmentation and friendships on distressing psychotic-like experiences (PLE) remains unknown. We investigate the relationships between neighborhood social fragmentation, number of friends, and distressing PLE among early adolescents.

METHODS

Data were collected from the Adolescent Brain Cognitive Development Study. Generalized linear mixed models tested associations between social fragmentation and distressing PLE, as well as the moderating role of the number of total and close friends.

RESULTS

Participants included 11 133 adolescents aged 9 to 10, with 52.3% being males. Greater neighborhood social fragmentation was associated with higher levels of distressing PLE (adjusted β = 0.05; 95% CI: 0.01-0.09). The number of close but not total friends significantly interacted with social fragmentation to predict distressing PLE (adjusted β = -0.02; 95% CI: -0.04 to <-0.01). Among those with fewer close friends, the association between neighborhood social fragmentation and distressing PLE was significant (adjusted β = 0.07; 95% CI: 0.03-0.11). However, among those with more close friends, the association was non-significant (adjusted β = 0.03; 95% CI: -0.01 to 0.07).

CONCLUSIONS

Greater neighborhood social fragmentation is associated with higher levels of distressing PLE, particularly among those with fewer close friends. Further research is needed to disentangle aspects of the interaction between neighborhood characteristics and the quality of social interactions that may contribute to psychosis, which would have implications for developing effective interventions at the individual and community levels.

Developmental perspectives on the origins of psychotic disorders: The need for a transdiagnostic approach

Research on serious mental disorders, particularly psychosis, has revealed highly variable symptom profiles and developmental trajectories prior to illness-onset. As Dante Cicchetti pointed out decades before the term "transdiagnostic" was widely used, the pathways to psychopathology emerge in a system involving equifinality and multifinality. Like most other psychological disorders, psychosis is associated with multiple domains of risk factors, both genetic and environmental, and there are many transdiagnostic developmental pathways that can lead to psychotic syndromes. In this article, we discuss our current understanding of heterogeneity in the etiology of psychosis and its implications for approaches to conceptualizing etiology and research. We highlight the need for examining risk factors at multiple levels and to increase the emphasis on transdiagnostic developmental trajectories as a key variable associated with etiologic subtypes. This will be increasingly feasible now that large, longitudinal datasets are becoming available and researchers have access to more sophisticated analytic tools, such as machine learning, which can identify more homogenous subtypes with the ultimate goal of enhancing options for treatment and preventive intervention.

Treated incidence of first episode psychosis in Sinop, Turkey: results of a 4-year admission-based study - SINOPsy

BACKGROUND

The incidence of psychotic disorders varies in different geographic areas. As there has been no report from Turkey, this study aimed to provide the treated incidence rate of first-episode psychosis (FEP) in a defined area.

METHODS

All individuals, aged 15-64 years, presenting with FEP (ICD-10 F20-29, F30-33) to mental health services in a defined catchment-area in Sinop which is located in the Black Sea region of the northern Turkey were recorded over a 4-year period (2009 to 2012). Incidence rates of psychotic disorders and their 95% confidence intervals (CIs) were estimated. Poisson regression was applied to estimate the differences in incidence rate ratio (IRR) by age, sex, and urbanicity.

RESULTS

One hundred and fifteen FEP participants were identified during the 4 years. Crude incidence rates of all psychoses, schizophrenia, other psychotic disorders, and affective psychotic disorders were respectively 38.5 (95% CI 27.1-49.9), 10.7 (95% CI 6.6-14.8), 10.0 (95% CI 5.7-14.3) and 17.7 (95% CI 11.3-24.2) per 100 000 person-years. After age-sex standardisation the rates increased slightly. There were no gender differences in the incidence rates. IRR of any psychotic disorder was highest in the youngest age group (15-24 years) compared to the oldest age group (55-64 years), 7.9 (95% CI 2.8-30.5). In contrast with previous studies, the incidence rate of any psychotic disorder was not significantly increased in urban areas compared with rural areas.

CONCLUSIONS

The current study, the first of its kind from Turkey, indicates that the risk of schizophrenia and other psychotic disorders in a lowly urbanised area of Turkey is comparable to those reported in Western European cities.

Social Deprivation and Population Density Trajectories Before and After Psychotic Disorder Diagnosis

Importance

People with psychosis are more likely to be born and live in densely populated and socioeconomically deprived environments, but it is unclear whether these associations are a cause or consequence of disorder.

Objective

To investigate whether trajectories of exposure to deprivation and population density before and after diagnosis are associated with psychotic disorders or nonpsychotic bipolar disorder.

Design, Setting, and Participants

This nested case-control study included all individuals born in Sweden between January 1, 1982, and December 31, 2001, diagnosed for the first time with an International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) psychotic disorder or nonpsychotic bipolar disorder between their 15th birthday and cohort exit (December 31, 2016). One sex- and birth year-matched control participant per case was selected. Data analysis was performed from July 2021 to June 2023.

Exposures

The main exposures were quintiles of neighborhood-level deprivation and population density each year from birth to age 14 years and from first diagnosis until cohort exit.

Main Outcomes and Measures

The main outcomes were the odds of a serious mental illness outcome associated with trajectories of deprivation and population density, before and after diagnosis in cases. Group-based trajectory modeling was used to derive trajectories of each exposure in each period. Logistic regression was used to examine associations with outcomes.

Results

A total of 53 458 individuals (median [IQR] age at diagnosis in case patients, 23.2 [15.0-34.8] years; 30 746 [57.5%] female), including 26 729 case patients and 26 729 control participants, were studied. From birth to early adolescence, gradients were observed in exposure to deprivation and population density trajectories during upbringing and psychotic disorder, with those in the most vs least deprived (adjusted odds ratio [AOR], 1.17; 95% CI, 1.08-1.28) and most vs least densely populated (AOR, 1.49; 95% CI, 1.34-1.66) trajectories at greatest risk. A strong upward mobility trajectory to less deprived neighborhoods was associated with similar risk to living in the least deprived trajectory (AOR, 1.01; 95% CI, 0.91-1.12). Only 543 case patients (2.0%) drifted into more deprived areas after diagnosis; people with psychotic disorder were more likely to belong to this trajectory (AOR, 1.38; 95% CI, 1.16-1.65) or remain in the most deprived trajectory (AOR, 1.36; 95% CI, 1.24-1.48) relative to controls. Patterns were similar for nonpsychotic bipolar disorder and deprivation but weaker for population density.

Conclusions and Relevance

In this case-control study, greater exposure to deprivation during upbringing was associated with increased risk of serious mental illness, but upward mobility mitigated this association. People with serious mental illness disproportionately remained living in more deprived areas after diagnosis, highlighting issues of social immobility. Prevention and treatment should be proportionately located in deprived areas according to need.

Associations Between Childhood Area-Level Social Fragmentation, Maladaptation to School, and Social Functioning Among Healthy Youth and Those at Clinical High Risk for Psychosis

BACKGROUND AND HYPOTHESIS

Although studies have identified social fragmentation as an important risk factor for schizophrenia and other psychotic disorders, it is unknown whether it may impact social functioning. This study investigates whether social fragmentation during childhood predicts maladaptation to school as well as social functioning during childhood and adulthood.

STUDY DESIGN

Data were collected from the North American Prodrome Longitudinal Study. Participants included adults at clinical high risk for psychosis (CHR-P) and healthy comparisons (HC). Maladaptation to school and social functioning during childhood were assessed retrospectively and social functioning in adulthood was assessed at baseline.

STUDY RESULTS

Greater social fragmentation during childhood was associated with greater maladaptation to school (adjusted β = 0.21; 95% CI: 0.02 to 0.40). Social fragmentation was not associated with social functioning during childhood (unadjusted β = -0.08; 95% CI: -0.31 to 0.15). However, greater social fragmentation during childhood predicted poorer social functioning in adulthood (adjusted β = -0.43; 95% CI: -0.79 to -0.07). Maladaptation to school mediated 15.7% of the association between social fragmentation and social functioning. The association between social fragmentation and social functioning was stronger among adults at CHR-P compared to HC (adjusted β = -0.42; 95% CI: -0.82 to -0.02).

CONCLUSIONS

This study finds that social fragmentation during childhood is associated with greater maladaptation to school during childhood, which in turn predicts poorer social functioning in adulthood. Further research is needed to disentangle aspects of social fragmentation that may contribute to social deficits, which would have implications for the development of effective interventions at the individual and community levels.

Trends in socioeconomic inequalities in incidence of severe mental illness - A population-based linkage study using primary and secondary care routinely collected data between 2000 and 2017

OBJECTIVE

In 2008, the UK entered a period of economic recession followed by sustained austerity measures. We investigate changes in inequalities by area deprivation and urbanicity in incidence of severe mental illness (SMI, including schizophrenia-related disorders and bipolar disorder) between 2000 and 2017.

METHODS

We analysed 4.4 million individuals from primary and secondary care routinely collected datasets (2000-2017) in Wales and estimated the incidence of SMI by deprivation and urbanicity measured by the Welsh Index of Multiple Deprivation (WIMD) and urban/rural indicator respectively. Using linear modelling and joinpoint regression approaches, we examined time trends of the incidence and incidence rate ratios (IRR) of SMI by the WIMD and urban/rural indicator adjusted for available confounders.

RESULTS

We observed a turning point of time trends of incidence of SMI at 2008/2009 where slope changes of time trends were significantly increasing. IRRs by deprivation/urbanicity remained stable or significantly decreased over the study period except for those with bipolar disorder sourced from secondary care settings, with increasing trend of IRRs (increase in IRR by deprivation after 2010: 1.6 % per year, 95 % CI: 1.0 %-2.2 %; increase in IRR by urbanicity 1.0 % per year, 95 % CI: 0.6 %-1.3 %).

CONCLUSIONS

There was an association between recession/austerity and an increase in the incidence of SMI over time. There were variations in the effects of deprivation/urbanicity on incidence of SMI associated with short- and long-term socioeconomic change. These findings may support targeted interventions and social protection systems to reduce incidence of SMI.

The ethnic density effect as a contextual influence in ecological disease models: Establishing its quantitative expression

Research suggests higher neighbourhood ethnic minority density to be associated with lessened chances of ethnic group illness. We focus on the density effect on psychosis, arguing that (at higher ethnic concentrations) it acts as a contextual influence attenuating the compositional influence whereby minority ethnicity is associated with higher psychosis risk. In terms of ecological disease regression, the ethnic density effect will then be apparent in nonlinear impacts of minority concentration. Contextual effects may also be evident in spatially varying regression coefficient models for psychosis. Nonlinearity or heterogeneity may be associated with other contextual processes where geography modifies demography (e.g. deprivation amplification). We illustrate these issues with an analysis of psychosis prevalence in 4835 London neighbourhoods. The data are collected in primary care (during 2019/20) using clinical diagnosis (e.g. based on referrals to specialists or psychosis hospitalisation), and refer to patients currently under care: such care may extend retrospectively over several years. The data offer a complete population perspective in contrast to survey data, which typically offer limited geographic perspectives. We consider impacts on psychosis prevalence of non-white ethnicity, as well as those of deprivation, social fragmentation and urbanicity. We find evidence suggesting nonlinear impacts of non-white ethnicity on psychosis (essentially flat risk above a threshold concentration), but find no evidence for deprivation amplification.

Polygenic contribution to the relationship of loneliness and social isolation with schizophrenia

Previous research suggests an association of loneliness and social isolation (LNL-ISO) with schizophrenia. Here, we demonstrate a LNL-ISO polygenic score contribution to schizophrenia risk in an independent case-control sample (N = 3,488). We then subset schizophrenia predisposing variation based on its effect on LNL-ISO. We find that genetic variation with concordant effects in both phenotypes shows significant SNP-based heritability enrichment, higher polygenic contribution in females, and positive covariance with mental disorders such as depression, anxiety, attention-deficit hyperactivity disorder, alcohol dependence, and autism. Conversely, genetic variation with discordant effects only contributes to schizophrenia risk in males and is negatively correlated with those disorders. Mendelian randomization analyses demonstrate a plausible bi-directional causal relationship between LNL-ISO and schizophrenia, with a greater effect of LNL-ISO liability on schizophrenia than vice versa. These results illustrate the genetic footprint of LNL-ISO on schizophrenia.

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.

Association Between Genetic Risk for Psychiatric Disorders and the Probability of Living in Urban Settings

IMPORTANCE

Urban residence has been highlighted as an environmental risk factor for schizophrenia and, to a lesser extent, several other psychiatric disorders. However, few studies have explored genetic effects on the choice of residence.

OBJECTIVE

To investigate whether individuals with genetic predisposition to a range of psychiatric disorders have an increased likelihood to live in urban areas.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional retrospective cohort study including genotypes, address history, and geographic distribution of population density in the UK based on census data from 1931-2011 was conducted. Polygenic risk score (PRS) analyses, genome-wide association studies, genetic correlation, and 2-sample mendelian randomization analyses were applied to 385 793 UK Biobank participants with self-reported or general practitioner registration-based address history. The study was conducted from February 2018 to May 2021, and data analysis was performed from April 2018 to May 2021.

MAIN OUTCOMES AND MEASURES

Population density of residence at different ages and movement during the life span between urban and rural environments.

RESULTS

In this cohort study of 385 793 unrelated UK Biobank participants (207 963 [54%] were women; age, 37-73 years; mean [SD], 56.7 [8] years), PRS analyses showed significant associations with higher population density across adult life (age 25 to >65 years) reaching highest significance at the 45- to 55-year age group for schizophrenia (88 people/km2; 95% CI, 65-98 people/km2), bipolar disorder (44 people/km2; 95% CI, 34-54 people/km2), anorexia nervosa (36 people/km2; 95% CI, 22-50 people/km2), and autism spectrum disorder (35 people/km2; 95% CI, 25-45 people/km2). The schizophrenia PRS was also significantly associated with higher birthplace population density (37 people/km2; 95% CI, 19-55 people/km2; P = 8 × 10-5). Attention-deficit/hyperactivity disorder PRS was significantly associated with reduced population density in adult life (-31 people/km2; 95% CI, -42 to -20 people/km2 at age 35-45 years). Individuals with higher PRS for schizophrenia, bipolar disorder, anorexia nervosa, and autism spectrum disorder and lower PRS for attention-deficit/hyperactivity disorder preferentially moved from rural environments to cities (difference in PRS with Tukey pairwise comparisons for schizophrenia: 0.05; 95% CI, 0.03 to 0.60; bipolar disorder: 0.10; 95% CI, 0.08 to 0.13; anorexia nervosa: 0.05; 95% CI, 0.03 to 0.07; autism spectrum disorder: 0.04; 95% CI 0.03 to 0.06; and attention-deficit/hyperactivity disorder: -0.09, 95% CI, -0.12 to -0.06). Genetic correlation results were largely consistent with PRS analyses, whereas mendelian randomization provided support for associations between schizophrenia and bipolar disorder and living in high population-density areas.

CONCLUSIONS AND RELEVANCE

These findings suggest that a high genetic risk for a variety of psychiatric disorders may affect an individual's choice of residence. This result supports the hypothesis of genetic selection of an individual's environment, which intersects the traditional gene-environment dichotomy.

From Womb to Neighborhood: A Racial Analysis of Social Determinants of Psychosis in the United States

The authors examine U.S.-based evidence that connects characteristics of the social environment with outcomes across the psychosis continuum, from psychotic experiences to schizophrenia. The notion that inequitable social and economic systems of society significantly influence psychosis risk through proxies, such as racial minority and immigrant statuses, has been studied more extensively in European countries. While there are existing international reviews of social determinants of psychosis, none to the authors' knowledge focus on factors in the U.S. context specifically-an omission that leaves domestic treatment development and prevention efforts incomplete and underinformed. In this review, the authors first describe how a legacy of structural racism in the United States has shaped the social gradient, highlighting consequential racial inequities in environmental conditions. The authors offer a hypothesized model linking structural racism with psychosis risk through interwoven intermediary factors based on existing theoretical models and a review of the literature. Neighborhood factors, cumulative trauma and stress, and prenatal and perinatal complications were three key areas selected for review because they reflect social and environmental conditions that may affect psychosis risk through a common pathway shaped by structural racism. The authors describe evidence showing that Black and Latino people in the United States suffer disproportionately from risk factors within these three key areas, in large part as a result of racial discrimination and social disadvantage. This broad focus on individual and community factors is intended to provide a consolidated space to review this growing body of research and to guide continued inquiries into social determinants of psychosis in U.S. contexts.

Environmental Risk Factors for Schizophrenia and Bipolar Disorder and Their Relationship to Genetic Risk: Current Knowledge and Future Directions

Schizophrenia (SZ) and bipolar disorder (BD) are severe psychiatric disorders which result from complex interplay between genetic and environmental factors. It is well-established that they are highly heritable disorders, and considerable progress has been made identifying their shared and distinct genetic risk factors. However, the 15-40% of risk that is derived from environmental sources is less definitively known. Environmental factors that have been repeatedly investigated and often associated with SZ include: obstetric complications, infections, winter or spring birth, migration, urban living, childhood adversity, and cannabis use. There is evidence that childhood adversity and some types of infections are also associated with BD. Evidence for other risk factors in BD is weaker due to fewer studies and often smaller sample sizes. Relatively few environmental exposures have ever been examined for SZ or BD, and additional ones likely remain to be discovered. A complete picture of how genetic and environmental risk factors confer risk for these disorders requires an understanding of how they interact. Early gene-by-environment interaction studies for both SZ and BD often involved candidate genes and were underpowered. Larger samples with genome-wide data and polygenic risk scores now offer enhanced prospects to reveal genetic interactions with environmental exposures that contribute to risk for these disorders. Overall, although some environmental risk factors have been identified for SZ, few have been for BD, and the extent to which these account for the total risk from environmental sources remains unknown. For both disorders, interactions between genetic and environmental risk factors are also not well understood and merit further investigation. Questions remain regarding the mechanisms by which risk factors exert their effects, and the ways in which environmental factors differ by sex. Concurrent investigations of environmental and genetic risk factors in SZ and BD are needed as we work toward a more comprehensive understanding of the ways in which these disorders arise.

Air Pollution as Risk Factor for Mental Disorders: In Search for a Possible Link with Alzheimer's Disease and Schizophrenia

As a global problem that has increasingly been causing worldwide concern, air pollution poses a significant and serious environmental risk to health. Risks of cardiovascular and respiratory diseases, as well as various types of cancer, have been consistently associated with the exposure to air pollutants. More recently, various studies have also shown that the central nervous system is also attacked by air pollution. Air pollution appears to be strongly associated with a higher risk of cognitive defects, neurodevelopmental (e.g., schizophrenia) and neurodegenerative (e.g., Alzheimer's disease) disorders. Subjects with schizophrenia, as well as subjects with Alzheimer's disease, experience a variety of neuropsychological deficits and cognitive impairments. This determines an adverse effect on social and professional functioning, and it contributes to the long-term disease burden. However, no final conclusions have been drawn on the matter of the direct relationship between schizophrenia and Alzheimer's disease. In recent years, the topic of urbanicity and mental health has become increasingly important. Urban exposure to environmental toxins and pollution is currently described as a reliable risk factor for schizophrenia and other psychoses, and it has been demonstrated more and more how exposure to air pollutants is associated with increased risk of dementia. Pathways by which air pollution can target and damage the brain, leading to an increased risk for developing schizophrenia and Alzheimer's disease, are multiple and complex. Results from epidemiological studies suggest potential associations, but are still insufficient to confirm causality. Further studies are needed in order to verify this hypothesis. And if confirmed, the clinical implications could be of substantial relevance for both public and mental health.

Characteristics associated with the risk of psychosis among immigrants and their descendants in France

OBJECTIVE

To explore the sociodemographic characteristics that might explain the increased incidence of psychosis among immigrants and their descendants in France.

METHODS

Data were collected for all subjects with first contact for psychosis aged between 18 and 64 years, in two catchment areas in the Paris region. Incidence rates (IR) and incidence rate ratios (IRR) were adjusted for gender and age.

RESULTS

During 805,396 persons-year at risk, we identified 321 cases of first-episode psychosis, of which 129 were immigrants and 78 descendants of immigrants. We found that the geographic origin was associated with the risk of psychosis although generation has little impact. Sub-Saharan African immigrants and their descendants showed the highest risk (IRR = 3.1 and IRR = 2.9, respectively). We observed that living in deprived areas increased the incidence of psychosis (IRR = 1.3, 95CI%: 1.0-1.6), particularly among immigrants (IRR = 1.6; 95% CI: 1.1-2.5). Finally, our study showed that subjects having unstable housing (a proxy for "hard to count population") could inflate the incidence rates among immigrants.

CONCLUSION

The current study shows that the increased risk of psychosis in groups with an immigration background in France is associated with their origin and highlights the importance of socioeconomic factors in modulating this risk.

Prevalence and associated factors of DSM-5 insomnia disorder in the general population of Qatar

BACKGROUND

Epidemiological studies of insomnia in the Middle East remain scarce. The present study aimed to estimate the prevalence of insomnia and explore its associations in the general population of Qatar. With almost 100 nationalities, Qatar is one of the most culturally diverse, richest, and fastest developing countries in the Arabian Peninsula.

METHODS

A probability sample of community-dwelling adults were surveyed in February of 2019. A total of 1611 respondents completed face-to-face interviews in Arabic or English. Logistic regression modeled associations with insomnia, our dependent variable, as defined by a score of ≤16 on the eight-item Sleep Condition Indicator or according to criteria for insomnia in the Diagnostic & Statistical Manual of Mental Disorders, fifth edition or DSM-5.

RESULTS

Approximately, 5.5% of the sample screened positive for insomnia and the 30-day prevalence of those who met all the DSM-5 criteria for insomnia disorder was 3.0%. In addition, 2.0% of the sample screened positive for depression and 3.4% for anxiety in the past 2 weeks. Multivariable analysis showed the following were significantly associated with insomnia: Arab ethnicity, young age, unemployment, being married, having less than high school education, fair or poor health, anxiety, and depression.

CONCLUSIONS

Insomnia prevalence was in the lower range of previously reported DSM-defined estimates from developed Western countries. Our findings highlight the need for raising awareness and improving sleep hygiene in potential risk groups such as younger adults and those of Arab ethnicity, in addition to incorporating insomnia screening in the provision of mental health services.

Pharmacotherapy of schizophrenia: Mechanisms of antipsychotic accumulation, therapeutic action and failure

Schizophrenia is a multi-dimensional disorder with a complex and mostly unknown etiology, leading to a severe decline in life quality. Antipsychotic drugs (APDs) remain beneficial interventions in the treatment of the disorder, but vary significantly in binding profile, clinical effects and adverse reactions. The present review summarizes the main principles of APD mechanisms of action with a particular focus on recent findings in APD accumulation and its role in the therapeutic efficacy and treatment failure. High and low doses of APDs were shown to be effective in different dimensions of antipsychotic-like behaviour in rodent models. Efficacy of the APDs correlates with high dopamine D2 receptor occupancy, which occurs quickly after drug administration. However, onset and peak of action are delayed up to several days or weeks. APD accumulation via acidic trapping in synaptic vesicles is considered to underlie the time course of APD action. Use-dependent exocytosis, co-release with dopamine and serotonin and inhibition of ion channels impact on the neuronal transmission and determine effects of APDs. Disruption in accumulating properties leads to diminished APD effects. In addition, long-term APD administration at therapeutic doses leads to treatment failure both in animal models and in humans. APD failure was associated with treatment induced neuroadaptations, including a decline in extracellular dopamine levels, dopamine transporter upregulation, and altered neuronal firing. However, enhanced synaptic vesicle release has also been reported. APD loss of efficacy may be reversed through inhibition of the dopamine transporter or switching the administration regimen from continuous to intermittent. Thus, manipulating the accumulation properties of APDs, changes in the administration regimen and doses, or co-administration with dopamine transporter inhibitors may be considered to yield benefits in the development of new effective strategies in the treatment of schizophrenia.

Sociodemographic Factors and Medication Administration Factors Affecting Re - Hospitalization in Patients with Schizophrenia - Spectrum Disorders

Schizophrenia - spectrum disorders have been shown to have large economic costs for the society due to hospitalizations. Long Acting Injections (LAIs) have been shown to promote adherence and reduce hospitalizations. However, socio-demographic and environmental variables have been shown to be associated with relapses. The present study attempted to explore relationships between rehospitalisation and such variables by analysing data from the Attitudes Study. Our findings validate previous literature on LAIs showing a larger effect of route of drug administration on hospitalizations. However, our study also highlights the importance of living circumstances and ethnicity that were shown to have an effect on hospitalizations and explained a larger part of the variance when it came to furthers hospitalisations. Furthermore, associations of variables relating to disease history with variables like gender, education and employment are presented highlighting the importance of a multi-approach model when it comes to preventing future hospitalizations.

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.

The P2X7 Receptor: Central Hub of Brain Diseases

The P2X7 receptor is a cation channel activated by high concentrations of adenosine triphosphate (ATP). Upon long-term activation, it complexes with membrane proteins forming a wide pore that leads to cell death and increased release of ATP into the extracellular milieu. The P2X7 receptor is widely expressed in the CNS, such as frontal cortex, hippocampus, amygdala and striatum, regions involved in neurodegenerative diseases and psychiatric disorders. Despite P2X7 receptor functions in glial cells have been extensively studied, the existence and roles of this receptor in neurons are still controversially discussed. Regardless, P2X7 receptors mediate several processes observed in neuropsychiatric disorders and brain tumors, such as activation of neuroinflammatory response, stimulation of glutamate release and neuroplasticity impairment. Moreover, P2X7 receptor gene polymorphisms have been associated to depression, and isoforms of P2X7 receptors are implicated in neuropsychiatric diseases. In view of that, the P2X7 receptor has been proposed to be a potential target for therapeutic intervention in brain diseases. This review discusses the molecular mechanisms underlying P2X7 receptor-mediated signaling in neurodegenerative diseases, psychiatric disorders, and brain tumors. In addition, it highlights the recent advances in the development of P2X7 receptor antagonists that are able of penetrating the central nervous system.

Relegating Psychosis: Blood Work and "Routine Connection" in the Clozapine Clinic

This paper attends to the sociality available in the clozapine clinic regimen and suggests that the social dimensions of clozapine treatment may be as important as the biochemical efficacy of clozapine. The clozapine clinic is where people diagnosed with chronic schizophrenia who take the antipsychotic clozapine go for routine monitoring of clozapine side effects, particularly haematological effects. Psychopharmaceutical treatments are often criticized for being reductionistic and dehumanizing, but clozapine clinics offer increased clinical contact in the age of deinstitutionalization. The inadvertent social benefits of biomedically reductive treatments have not previously been ethnographically attended to in the clozapine-only context. Drawing on 18 months of ethnographic fieldwork with 43 clozapine clients and 16 clinical caregivers in two clozapine clinics in the United Kingdom in Australia, I argue that routine clinical attachments in the clozapine clinic can serve a therapeutic role in terms of providing opportunities for clients' health agency, social competence and accountability. This socio-therapeutic quality appeared to be available because the clinical emphasis was not on psychotic illness. It depended, however, on reliable and familiar social exchanges inside the clinic and on the predictability of clinical activity. The importance of unemotional but unfailing relationships and rhythms in the clozapine clinic context echoes cross-cultural findings about how schizophrenia is managed more productively in environments that invite more neutral and equal social exchanges.

Area deprivation, urbanicity, severe mental illness and social drift - A population-based linkage study using routinely collected primary and secondary care data

We investigated whether associations between area deprivation, urbanicity and elevated risk of severe mental illnesses (SMIs, including schizophrenia and bipolar disorder) is accounted for by social drift or social causation. We extracted primary and secondary care electronic health records from 2004 to 2015 from a population of 3.9 million. We identified prevalent and incident individuals with SMIs and their level of deprivation and urbanicity using the Welsh Index of Multiple Deprivation (WIMD) and urban/rural indicator. The presence of social drift was determined by whether odds ratios (ORs) from logistic regression is greater than the incidence rate ratios (IRRs) from Poisson regression. Additionally, we performed longitudinal analysis to measure the proportion of change in deprivation level and rural/urban residence 10 years after an incident diagnosis of SMI and compared it to the general population using standardised rate ratios (SRRs). Prevalence and incidence of SMIs were significantly associated with deprivation and urbanicity (all ORs and IRRs significantly >1). ORs and IRRs were similar across all conditions and cohorts (ranging from 1.1 to 1.4). Results from the longitudinal analysis showed individuals with SMIs are more likely to move compared to the general population. However, they did not preferentially move to more deprived or urban areas. There was little evidence of downward social drift over a 10-year period. These findings have implications for the allocation of resources, service configuration and access to services in deprived communities, as well as, for broader public health interventions addressing poverty, and social and environmental contexts.

Exposure to air pollution during childhood and risk of developing schizophrenia: a national cohort study

BACKGROUND

Ambient air pollution affects neurological function, but its association with schizophrenia risk is unclear. We investigated exposure to nitrogen oxides (NO_X) as a whole and nitrogen dioxide (NO₂) specifically, as well as PM₁₀, and PM_2·5, during childhood and subsequent schizophrenia risk.

METHODS

People born in Denmark from 1980 to 1984 (N=230 844), who were residing in the country on their tenth birthday, and who had two Danish-born parents were followed-up from their tenth birthday until schizophrenia diagnosis or Dec 31, 2016. Mean daily exposure to each pollutant (NO₂, NO_X, PM₁₀, and PM_2·5) at all of an individual's residential addresses from birth to their tenth birthday was modelled. Incidence rate ratios, cumulative incidence, and population attributable risks were calculated using survival analysis techniques.

FINDINGS

We analysed data between Aug 1, 2018, and Nov 15, 2019. Of 230 844 individuals included, 2189 cohort members were diagnosed with schizophrenia during follow-up. Higher concentrations of residential NO₂ and NO_X exposure during childhood were associated with subsequent elevated schizophrenia risk. People exposed to daily mean concentrations of more than 26·5 μg/m³ NO₂ had a 1·62 (95% CI 1·41-1·87) times increased risk compared with people exposed to a mean daily concentration of less than 14·5 μg/m³. The absolute risks of developing schizophrenia by the age of 37 years when exposed to daily mean concentrations of more than 26·5 μg/m³ NO₂ between birth and 10 years were 1·45% (95% CI 1·30-1·62%) for men and 1·03% (0·90-1·17) for women, whereas when exposed to a mean daily concentration of less than 14·5 μg/m³, the risk was 0·80% (95% CI 0·69-0·92%) for men and 0·67% (0·57-0·79) for women. Associations between exposure to PM_2·5 or PM₁₀ and schizophrenia risk were less consistent.

INTERPRETATION

If the association between air pollution and schizophrenia is causal, reducing ambient air pollution including NO₂ and NO_X could have a potentially considerable effect on lowering schizophrenia incidence at the population level. Further investigations are necessary to establish a causal relationship.

FUNDING

Lundbeck Foundation, Stanley Medical Research Institute, European Research Council, NordForsk, Novo Nordisk Foundation, National Health and Medical Research Council, Danish National Research Foundation.

Association of Wider Social Environment with Relapse in Schizophrenia: Registry Based Six-Year Follow-Up Study

Introducton

The impact of social environment on the frequency and prevalence of schizophrenia is well known. However, in schizophrenia and other psychotic disorders, there are few studies which investigate the effect of social environment on disease prognosis and relapse. The aim of this study was to investigate the effect of neighborhood social capital level and address change on relapse in schizophrenia and similar psychotic disorders.

Methods

The research sample consisted of 147 patients (schizophrenia, 76.1%; n=112), who were being followed up at regular intervals of at most six months at the Psychotic Disorders Unit outpatient clinic. Patients were followed-up for relapse indicators between January 1, 2009 and December 31, 2013. During the follow-up, relapse criteria including hospitalization, increased need for help, self-harm, suicidal thoughts, violent behavior, suicide attempts, antipsychotic dose increase and electroconvulsive therapy were used. At least one of these criteria was accepted as a relapse for that period. Neighborhood social capital levels were obtained from a general public survey conducted in Izmir city center in 2008 and the voting rates in the neighborhood during the follow-up period. In addition, during the follow-up period, any change in the address of the patient was recorded.

Results

While there was no correlation between the neighborhood social environment and relapse, a significant relationship was found between relapse and address changes. The probability of relapse was 1.3 times higher in patients with change of address (95%CI: 1.0-1.6; p<0.05), and decreased likelihood of relapse was found as the duration of residence in the same neighborhood shortened (β: (-0.05) 95%CI: [(-0.10)-(-0.003)]; p<0.05).

Conclusion

In schizophrenia, relapse appears to be related with the narrow social environment (family, home address) in which the person lives, not with the wider social environment (social capital of the neighborhood). The need for adaptation to a new social environment that arises with a change of address, albeit narrowly, can lead to an increase in symptoms of schizophrenia as a psychosocial stressor.

Prevalence of mental illness in primary care and its association with deprivation and social fragmentation at the small-area level in England

BACKGROUND

We aimed to spatially describe mental illness prevalence in England at small-area geographical level, as measured by prevalence of depression, severe mental illness (SMI) and antidepressant prescription volume in primary care records, and how much of their variation was explained by deprivation, social fragmentation and sociodemographic characteristics.

METHODS

Information on prevalence of depression and SMI was obtained from the Quality and Outcomes Framework (QOF) administrative dataset for 2015/16 and the national dispensing dataset for 2015/16. Linear regression models were fitted to examine ecological associations between deprivation, social fragmentation, other sociodemographic characteristics and mental illness prevalence.

RESULTS

Mental illness prevalence varied within and between regions, with clusters of high prevalence identified across England. Our models explained 33.4-68.2% of variability in prevalence, but substantial variability between regions remained after adjusting for covariates. People in socially cohesive and socially deprived areas were more likely to be diagnosed with depression, while people in more socially fragmented and more socially deprived areas were more likely to be diagnosed with SMI.

CONCLUSIONS

Our findings suggest that to tackle mental health inequalities, attention needs to be targeted at more socially deprived localities. The role of social fragmentation warrants further investigation, and it is possible that depression remains undiagnosed in more socially fragmented areas. The wealth of routinely collected data can provide robust evidence to aid optimal resource allocation. If comparable data are available in other countries, similar methods could be deployed to identify high prevalence clusters and target funding to areas of greater need.

Association Between Parental Income During Childhood and Risk of Schizophrenia Later in Life

IMPORTANCE

Evidence linking parental socioeconomic position and offspring's schizophrenia risk has been inconsistent, and how risk is associated with parental socioeconomic mobility has not been investigated.

OBJECTIVE

To elucidate the association between parental income level and income mobility during childhood and subsequent schizophrenia risk.

DESIGN, SETTING, AND PARTICIPANTS

National cohort study of all persons born in Denmark from January 1, 1980, to December 31, 2000, who were followed up from their 15th birthday until schizophrenia diagnosis, emigration, death, or December 31, 2016, whichever came first. Data analyses were from March 2018 to June 2019.

EXPOSURE

Parental income, measured at birth year and at child ages 5, 10, and 15 years.

MAIN OUTCOMES AND MEASURES

Hazard ratios (HRs) for schizophrenia were estimated using Cox proportional hazard regression. Cumulative incidence values (absolute risks) were also calculated.

RESULTS

The cohort included 1 051 033 participants, of whom 51.3% were male. Of the cohort members, 7544 (4124 [54.7%] male) were diagnosed with schizophrenia during 11.6 million person-years of follow-up. There was an inverse association between parental income level and subsequent schizophrenia risk, with children from lower income families having especially elevated risk. Estimates were attenuated, but risk gradients remained after adjustment for urbanization, parental mental disorders, parental educational levels, and number of changes in child-parent separation status. A dose-response association was observed with increasing amount of time spent in low-income conditions being linked with higher schizophrenia risk. Regardless of parental income level at birth, upward income mobility was associated with lower schizophrenia risk compared with downward mobility. For example, children who were born and remained in the lowest income quintile at age 15 years had a 4.12 (95% CI, 3.71-4.58) elevated risk compared with the reference group, those who were born in and remained in the most affluent quintile, but even a rise from the lowest income quintile at birth to second lowest at age 15 years appeared to lessen the risk elevation (HR, 2.80; 95% CI, 2.46-3.17). On the contrary, for those born in the most affluent quintile, downward income mobility between birth and age 15 years was associated with increased risks of developing schizophrenia.

CONCLUSIONS AND RELEVANCE

This study's findings suggest that parental income level and income mobility during childhood may be linked with schizophrenia risk. Although both causation and selection mechanisms could be involved, enabling upward income mobility could influence schizophrenia incidence at the population level.

Individual-level and area-level socioeconomic status (SES) and schizophrenia: cross-sectional analyses using the evidence from 1.9 million Chinese adults

OBJECTIVES

Health disparities in schizophrenia are well established. However, it is less understood whether area-level socioeconomic status (SES) is differentially associated with schizophrenia depending on individual-level SES. Therefore, using a nationally large representative data, this study investigated the association between individual-level SES, area-level SES and their interaction with schizophrenia in Chinese adults from a multilevel perspective.

SETTING

Household interviews in 734 counties (districts), 2980 towns (streets) and 5964 communities (villages) from 31 provinces, People's Republic of China, as part of the cross-sectional survey of Second China National Sample Survey on Disability.

PARTICIPANTS

1 909 205 men and women aged 18 years old and above.

PRIMARY AND SECONDARY OUTCOME MEASURES

A screen followed by clinical diagnosis was used to identify schizophrenia, and schizophrenia was ascertained according to the International Statistical Classification of Diseases, 10th Revision (code F20).

RESULTS

1-SD increase in individual SES was associated with decreased risk of schizophrenia (OR=0.45, 95% CI 0.43 to 0.46). 1-SD increase in area-level SES was associated with increased risk of schizophrenia (OR=1.30, 95% CI 1.24 to 1.37). The interaction of individual SES and area-level SES was statistically significant (OR=1.05, 95% CI 1.02 to 1.08); as the level of area SES increased, schizophrenia risk of lower SES people grew faster than the risk of higher SES people.

CONCLUSIONS

Area-level SES is particularly important to mental health of low SES individuals, with low SES people in high SES counties having the highest risk of schizophrenia than other groups. Action to reduce SES disparities in schizophrenia will require attention to the area-level context of low SES adults.

Environmental pollution is associated with increased risk of psychiatric disorders in the US and Denmark

The search for the genetic factors underlying complex neuropsychiatric disorders has proceeded apace in the past decade. Despite some advances in identifying genetic variants associated with psychiatric disorders, most variants have small individual contributions to risk. By contrast, disease risk increase appears to be less subtle for disease-predisposing environmental insults. In this study, we sought to identify associations between environmental pollution and risk of neuropsychiatric disorders. We present exploratory analyses of 2 independent, very large datasets: 151 million unique individuals, represented in a United States insurance claims dataset, and 1.4 million unique individuals documented in Danish national treatment registers. Environmental Protection Agency (EPA) county-level environmental quality indices (EQIs) in the US and individual-level exposure to air pollution in Denmark were used to assess the association between pollution exposure and the risk of neuropsychiatric disorders. These results show that air pollution is significantly associated with increased risk of psychiatric disorders. We hypothesize that pollutants affect the human brain via neuroinflammatory pathways that have also been shown to cause depression-like phenotypes in animal studies.

A possible key role of vision in the development of schizophrenia

Based on a brief overview of the various aspects of schizophrenia reported by numerous studies, here we hypothesize that schizophrenia may originate (and in part be performed) from visual areas. In other words, it seems that a normal visual system or at least an evanescent visual perception may be an essential prerequisite for the development of schizophrenia as well as of various types of hallucinations. Our study focuses on auditory and visual hallucinations, as they are the most prominent features of schizophrenic hallucinations (and also the most studied types of hallucinations). Here, we evaluate the possible key role of the visual system in the development of schizophrenia.

Sociodemographic, environmental characteristics and comorbidities of older adults with schizophrenia who access community health service support: A national cross-sectional study

OBJECTIVES

Schizophrenia is a serious and chronic mental illness known to have broad ranging impacts for individuals across the lifespan, yet research on the disease in older adults is sparse. This study provides a profile of the sociodemographic, environmental and diagnostic characteristics of older community residents with schizophrenia using a national database.

METHODS

A cross-sectional sample of individuals who underwent community needs assessment using the standardised Home Care International Residential Assessment Instrument between 1 September 2012 and 31 January 2016 was utilised. Sociodemographic, diagnostic, and social and environmental variables were measured for individuals with a diagnosis of schizophrenia and compared to those without a diagnosis of schizophrenia. Statistical investigations employed bivariable and multivariable logistic regression models.

RESULTS

A total sample of 71,859 was eligible and 517 (0.7%) had a diagnosis of schizophrenia. The majority of the sociodemographic variables were statistically associated with schizophrenia in the adjusted analysis, except for ethnicity ( p = 0.35). Nearly all the measured social and environmental variables were adversely associated with having a diagnosis of schizophrenia, such as living in squalid conditions (adjusted odds ratio = 2.16; 95% confidence interval = [1.42, 3.28]). Participants with schizophrenia were significantly more likely to be diagnosed with all assessed psychiatric comorbidities ( p < 0.001) and diabetes mellitus ( p  = 0.002), whereas coronary heart disease ( p = 0.001) and other physical comorbidities ( p = 0.001) were found at significantly lower rates.

CONCLUSION

The profile of schizophrenia found here suggests some subtle differences in the demographic profile and distribution of medical comorbidities in the older population with schizophrenia. The results also suggest that this group continues to experience social disadvantage into old age. This requires the attention of policy-makers to ensure that services are tailored to the high social needs of these individuals.

Spatial distribution and temporal trends in social fragmentation in England, 2001-2011: a national study

OBJECTIVE

Social fragmentation is commonly examined in epidemiological studies of mental illness as high levels of social fragmentation are often found in areas with high prevalence of mental illness. In this study, we examine spatial and temporal patterns of social fragmentation and its underlying indicators in England over time.

SETTING

Data for social fragmentation and its underlying indicators were analysed over the decennial Censuses (2001-2011) at a small area geographical level (mean of 1500 people). Degrees of social fragmentation and temporal changes were spatially visualised for the whole of England and its 10 administrative regions. Spatial clustering was quantified using Moran's I; changes in correlations over time were quantified using Spearman's ranking correlation.

RESULTS

Between 2001 and 2011, we observed a strong persistence for social fragmentation nationally (Spearman's r=0.93). At the regional level, modest changes were observed over time, but marked increases were observed for two of the four social fragmentation underlying indicators, namely single people and those in private renting. Results supported our hypothesis of increasing spatial clustering over time. Moderate regional variability was observed in social fragmentation, its underlying indicators and their clustering over time.

CONCLUSION

Patterns of social fragmentation and its underlying indicators persisted in England which seem to be driven by the large increases in single people and those in private renting. Policies to improve social cohesion may have an impact on the lives of persons who experience mental illness. The spatial aspect of social fragmentation can inform the targeting of health and social care interventions, particularly in areas with strong social fragmentation clustering.

Social determinants of mental disorders and the Sustainable Development Goals: a systematic review of reviews

Mental health has been included in the UN Sustainable Development Goals. However, uncertainty exists about the extent to which the major social determinants of mental disorders are addressed by these goals. The aim of this study was to develop a conceptual framework for the social determinants of mental disorders that is aligned with the Sustainable Development Goals, to use this framework to systematically review evidence regarding these social determinants, and to identify potential mechanisms and targets for interventions. We did a systematic review of reviews using a conceptual framework comprising demographic, economic, neighbourhood, environmental events, and social and culture domains. We included 289 articles in the final Review. This study sheds new light on how the Sustainable Development Goals are relevant for addressing the social determinants of mental disorders, and how these goals could be optimised to prevent mental disorders.

Demographic and Clinical Correlates of Social Cognition in Schizophrenia: Observation from India

PURPOSE

Although deficits in social cognition (SC) had been recognized as a hallmark of schizophrenia, quality data in Indian context were limited. The purpose of the current research was to determine the demographic and clinical correlates of SC in schizophrenia.

METHODS

Between February 2014 and January 2015, a case-control study was conducted in Chhattisgarh, India, among 100 paranoid schizophrenia patients (ICD-10) from two psychiatric hospitals and 100 neighborhood-based healthy (28-item General Health Questionnaire) controls. After obtaining signed consent, SC was assessed among 20-35-year-old, high school or more educated subjects ensuring eligibility for appropriate scales.

RESULTS

Patients had poorer social knowledge (adjusted-beta-coefficient [AC] = -4.89 [-6.32, -3.45]) and lower predicted mean score for internal attribution of negative event (AC: -0.72 [-1.17, -0.27]). Nonrecognition of facial expressions especially for anger (adjusted-odds-ratio [AOR] = 3.50 [1.17, 10.51]), surprise (AOR = 2.91 [1.36, 6.25]) and fear (AOR = 2.35 [1.11, 5.01]) was more common among cases. Wrong recognition of expressions was less likely among females (for surprise: AOR = 0.35 [0.13, 0.93]) and educated (for sadness: AOR = 0.11 [0.02, 0.58]) but more common among wealthy (for surprise: AOR = 4.58 [1.22, 17.19]) and urban (for fear: unadjusted odds ratios = 4.30 [1.53, 12.03]) subjects. If recognized expressions correctly, females were more likely to perceive higher intensity of anger (AOR = 4.30 [1.80, 10.29]) and happiness (AOR = 4.22 [1.66, 10.72]). Higher intensity was perceived by more educated subjects regarding anger (AOR = 2.57 [1.04, 6.34]) but not for happiness (AOR = 0.09 [0.01, 0.79]). Unmarried/divorced/separated perceived happiness (AOR = 2.86 [1.02, 7.97]) with more intensity while those in joint families perceived sadness (AOR = 2.80 [1.22, 6.41]) and fear (AOR = 2.28 [1.01, 5.16]) with more intensity.

CONCLUSION

A significant impairment in SC was observed among paranoid schizophrenia cases in Chhattisgarh, India. Intervention and further research addressing identified issues of SC need to target specific subpopulations, among schizophrenia patients.

The role of ethnicity in pathways to emergency psychiatric services for clients with psychosis

BACKGROUND

This study investigates the role of ethnicity in pathways to emergency mental health care in Toronto for clients with psychosis, while taking into account neighborhood factors. Previous literature has focused on Afro-Caribbean clients, reporting an increased risk of accessing mental health care through negative pathways.

METHODS

A retrospective chart review for clients from 6 different ethnic origin groups presenting with psychosis - East Asian, South Asian, Black African, Black Caribbean, White European, and White North American - was undertaken in a psychiatric emergency department (ED). Logistic regression models were constructed to examine the relationship between pathways to care (involuntary detention under the Mental Health Act (MHA), police or ambulance referral, accompaniment by family or friends) with individual and neighbourhood factors.

RESULTS

A total of 765 clients were included in the study. East Asian (OR =2.36, p < 0.01) and South Asian (OR 2.99, p < 0.01) origin clients have increased odds of presenting to the ED while involuntarily detained under the MHA. Involuntary status under the MHA increased the odds of presenting via police or ambulance (OR 8.27, p < 0.001). East Asian origin clients have increased odds of presenting to the ED by police or ambulance (OR =2.10, p < 0.05). Clients from neighbourhoods with higher levels of residential instability have increased odds of presenting by police or ambulance (OR =1.35, p < 0.01), while clients from neighbourhoods with higher levels of ethnic concentration have increased odds of being accompanied to the ED by family or friends (OR =1.33, p < 0.01).

CONCLUSION

In contrast to previous studies, East Asian and South Asian origin clients with psychosis have increased odds of a coercive pathway to emergency psychiatric services in Toronto. Black African and Black Caribbean origin clients do not have increased odds of a coercive pathway. Clients living in areas with high levels of residential instability are more likely to encounter a negative pathway. Ethnic concentration may be a supportive factor in family and friend accompaniment.

Examining patient race and area predictors of inpatient admission for schizophrenia among hospital users in California

According to international research African-Caribbean and Black African populations have increased risk of hospitalization for schizophrenia, compared to Whites. Less is known about admission risk for other racial-ethnic groups. This study investigated racial-ethnic differences in hospital admission for schizophrenia in California. It also investigated the influence of area social factors (racial-ethnic neighborhood composition, and per capita income) and health service factors (presence of primary care clinics). The study sample included individuals admitted to a California hospital during 1990-2005 with a primary appendicitis related diagnosis, and without a prior or concurrent indication of schizophrenia. The adjusted logistic model examined how patient racial-ethnicity (White, Black, Hispanic, Other), other personal, area social characteristics and presence of primary care clinics influenced hospital admissions for schizophrenia. Black individuals were almost twice as likely as Whites to be admitted while Hispanics and Other race individuals were less to be admitted. In addition, male sex, having more comorbidities and living in areas with greater proportions of non-Whites increased risk. The increased risk for Blacks compared to Whites was consistent with the existing literature. However, this is among the first studies to report that Hispanics had a reduced risk of admission for schizophrenia, compared to Whites. Future studies may want to include a broader range of health services to better understand patterns of care use among individuals with schizophrenia.

Schizophrenia

Schizophrenia is a complex, heterogeneous behavioural and cognitive syndrome that seems to originate from disruption of brain development caused by genetic or environmental factors, or both. Dysfunction of dopaminergic neurotransmission contributes to the genesis of psychotic symptoms, but evidence also points to a widespread and variable involvement of other brain areas and circuits. Disturbances of synaptic function might underlie abnormalities of neuronal connectivity that possibly involves interneurons, but the precise nature, location, and timing of these events are uncertain. At present, treatment mainly consists of antipsychotic drugs combined with psychological therapies, social support, and rehabilitation, but a pressing need for more effective treatments and delivery of services exists. Advances in genomics, epidemiology, and neuroscience have led to great progress in understanding the disorder, and the opportunities for further scientific breakthrough are numerous--but so are the challenges.

Neighbourhood level social deprivation and the risk of psychotic disorders: a systematic review

PURPOSE

The incidence of psychotic disorders varies according to the geographical area, and it has been investigated whether neighbourhood level factors may be associated with this variation. The aim of this systematic review is to collate and appraise the literature on the association between social deprivation and the incidence or risk for psychotic disorders.

METHOD

A systematic review was conducted, and studies were included if they were in English, provided a measure of social deprivation for more than one geographically defined area and examined either the correlation, rate ratio or risk of psychotic disorder. A defined search strategy was undertaken with Medline, CINAHL Plus and PsychInfo databases.

RESULTS

A total of 409 studies were identified in the search, of which 28 fulfilled the inclusion criteria. Of these, four examined the association between social deprivation at the time of birth, three examined the putative prodrome of psychosis or those at ultra-high risk (UHR) for psychosis, and 23 examined the time at presentation with a first episode of psychosis (FEP) (one study examined two time points and one study included both UHR and FEP). Three of the studies that examined the level of social deprivation at birth found an association with a higher risk for psychotic disorders and increased social deprivation. Seventeen of the 23 studies found that there was a higher risk or rate of psychotic disorders in more deprived neighbourhoods at the time of presentation; however, adjusting for individual factors tended to weaken this association. Limited research has been conducted in the putative prodromal stage and has resulted in conflicting findings.

CONCLUSIONS

Research conducted to date has not definitively identified whether the association is a result of social causation or social drift; however, the findings do have significant implications for service provision, such as the location and access of services.

Spatial distribution of psychotic disorders in an urban area of France: an ecological study

Previous analyses of neighbourhood variations of non-affective psychotic disorders (NAPD) have focused mainly on incidence. However, prevalence studies provide important insights on factors associated with disease evolution as well as for healthcare resource allocation. This study aimed to investigate the distribution of prevalent NAPD cases in an urban area in France. The number of cases in each neighbourhood was modelled as a function of potential confounders and ecological variables, namely: migrant density, economic deprivation and social fragmentation. This was modelled using statistical models of increasing complexity: frequentist models (using Poisson and negative binomial regressions), and several Bayesian models. For each model, assumptions validity were checked and compared as to how this fitted to the data, in order to test for possible spatial variation in prevalence. Data showed significant overdispersion (invalidating the Poisson regression model) and residual autocorrelation (suggesting the need to use Bayesian models). The best Bayesian model was Leroux's model (i.e. a model with both strong correlation between neighbouring areas and weaker correlation between areas further apart), with economic deprivation as an explanatory variable (OR = 1.13, 95% CI [1.02-1.25]). In comparison with frequentist methods, the Bayesian model showed a better fit. The number of cases showed non-random spatial distribution and was linked to economic deprivation.

Neighbourhood characteristics and the incidence of first-episode psychosis and duration of untreated psychosis

BACKGROUND

The incidence of psychotic disorders varies between geographical areas and it has been hypothesized that neighbourhood-level factors may influence this variation. It is also plausible that the duration of untreated psychosis (DUP) is associated with neighbourhood characteristics. The aims of this study were to determine whether the incidence of first-episode psychosis (FEP) and the DUP are associated with the level of social deprivation, fragmentation, social capital and population density.

METHOD

All individuals with a FEP from a geographical defined catchment area over a 5-year period were included. Age-standardized incidence rates were calculated for each neighbourhood factor.

RESULTS

A total of 292 cases of FEP were included in the study and 45% had a diagnosis of a schizophrenia-spectrum disorder. The age standardized incidence rate of FEP in the most deprived area was 72.4 [95% confidence interval (CI) 26.4-162.7] per 100 000 person-years compared with 21.5 (95% CI 17.6-26.0) per 100 000 person-years in the most affluent areas. This represents a 3.4-fold increase in FEP incidence in the most deprived areas. The incidence of FEP was also increased in neighbourhoods that were more socially fragmented [incidence rate ratio (IRR) = 2.40, 95% CI 1.05-5.51, p = 0.04] and there was a trend for the incidence to be increased in neighbourhoods with lower social capital (IRR = 1.43, 95% CI 0.99-2.06, p = 0.05). The median DUP was 4 months and was higher in more socially fragmented neighbourhoods.

CONCLUSIONS

The incidence of psychotic disorders is related to neighbourhood factors and it may be useful to consider neighbourhood factors when allocating resources for early intervention services.

Social disorganization of neighborhoods and incidence of psychotic disorders: a 7-year first-contact incidence study

BACKGROUND

Environmental factors such as urban birth and ethnic minority position have been related to risk for psychotic disorders. There is some evidence that not only individual, but also neighborhood characteristics influence this risk. The aim of this study was to investigate social disorganization of neighborhoods and incidence of psychotic disorders.

METHOD

The research was a 7-year first-contact incidence study of psychotic disorders in The Hague. Neighborhood characteristics included continuous, dichotomous and cumulative measures of socio-economic level, residential mobility, ethnic diversity, proportion of single person households, voter turnout, population density and crime level. Using multilevel Poisson regression analysis, incidence rate ratios (IRRs) and 95% confidence intervals (CIs) of psychotic disorders were calculated for the indicators of neighborhood social disorganization.

RESULTS

A total of 618 incident cases were identified. Neighborhood socio-economic level and residential mobility had the strongest association with incidence of psychotic disorders [individual-level adjusted Wald χ2 1 = 13.03 (p = 0.0003) and 5.51 (p = 0.02), respectively]. All but one (proportion of single person households) of the dichotomous neighborhood indicators were significantly associated with a higher IRR. The cumulative degree of neighborhood social disorganization was strongly and linearly associated with the incidence of psychotic disorders (trend test, Wald χ2 5 = 25.76, p = 0.0001). The IRR in neighborhoods with the highest degree of social disorganization was 1.95 (95% CI 1.38-2.75) compared with the lowest disorganization category.

CONCLUSIONS

The findings suggest that the risk for developing a psychotic disorder is higher for people living in socially disorganized environments. Longitudinal studies are needed to investigate causality.

Elevated levels of kynurenic acid during gestation produce neurochemical, morphological, and cognitive deficits in adulthood: implications for schizophrenia

The levels of kynurenic acid (KYNA), an endogenous negative modulator of alpha7 nicotinic acetylcholine receptors (α7nAChRs), are elevated in the brains of patients with schizophrenia (SZ). We reported that increases of brain KYNA in rats, through dietary exposure to its precursor kynurenine from embryonic day (ED)15 to postnatal day (PD) 21, result in neurochemical and cognitive deficits in adulthood. The present experiments focused on the effects of prenatal exposure to elevated kynurenine on measures of prefrontal excitability known to be impaired in SZ. Pregnant dams were fed a mash containing kynurenine (100 mg/day; progeny = EKYNs) from ED15 until ED22. Controls were fed an unadulterated mash (progeny = ECONs). The dietary loading procedure elevated maternal and fetal plasma kynurenine (2223% and 693% above controls, respectively) and increased fetal KYNA (forebrain; 500% above controls) on ED21. Elevations in forebrain KYNA disappeared after termination of the loading (PD2), but KYNA levels in the prefrontal cortex (PFC) were unexpectedly increased again when measured in adults (PD56-80; 75% above controls). We also observed changes in several markers of prefrontal excitability, including expression of the α7nAChR (22% and 17% reductions at PD2 and PD56-80), expression of mGluR2 (31% and 24% reductions at ED21 and PD56-80), dendritic spine density (11-14% decrease at PD56-80), subsensitive mesolimbic stimulation of glutamate release in PFC, and reversal/extra-dimensional shift deficits in the prefrontally-mediated set-shifting task. These results highlight the deleterious impact of elevated KYNA levels during sensitive periods of early development, which model the pathophysiological and cognitive deficits seen in SZ.

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 impact of immigration and visible minority status on psychosis symptom profile

PURPOSE

Immigrants have heightened risks of psychotic disorders, and it is proposed that migration influences symptom profiles. The purpose of this study was to investigate if either migration experience and/or visible minority status affected symptom profiles, using a cross-culturally validated five-factor model of the Positive and Negative Syndrome Scale (PANSS), in patients with broadly defined psychotic disorders.

METHODS

PANSS was assessed in a large catchment area based sample of patients with psychotic disorders verified with the Structured Clinical Interview for DSM-IV (n = 1,081). Symptom profiles based on Wallwork et al. five-factor model were compared for Norwegians (73 %), white immigrants (10.5 %), and visible minority groups (16.5 %).

RESULTS

Visible minorities were significantly younger, had less education, more often a schizophrenia diagnosis and higher PANSS positive, negative and disorganized/concrete factor scores than Norwegians and white immigrants. After controlling for confounders only the items "Delusions" and "Difficulty in abstract thinking" differed between groups. Multivariate analyses indicated that these items were not associated with immigration per se, but rather belonging to a visible minority.

CONCLUSION

We found mostly similarities in psychotic symptoms between immigrants and Norwegians when using a cross-culturally validated five-factor model of the PANSS. Immigration did not directly influence psychotic symptom profiles but visible minority groups had higher levels of "Delusions" and "Difficulty in abstract thinking", both symptoms that are partially context dependent.

Neighborhood linking social capital as a predictor of psychiatric medication prescription in the elderly: a Swedish national cohort study

OBJECTIVES

Little is known about the association between neighborhood linking social capital and psychiatric medication in the elderly. The present study analyzes whether there is an association between linking social capital (a theoretical concept describing the amount of trust between individuals and societal institutions) and prescription of antipsychotics, anxiolytics, hypnotics/sedatives, antidepressants, or anti-dementia drugs.

DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS

The entire Swedish population aged 65+, a total of 1,292,816 individuals, were followed from 1 July 2005 until first prescription of psychiatric medication, death, emigration, or the end of the study on 31 December 2010. Small geographic units were used to define neighborhoods. The definition of linking social capital was based on mean voting participation in each neighborhood unit, categorized in three groups. Multilevel logistic regression was used to estimate odds ratios (ORs) and between-neighborhood variance in three different models.

RESULTS

There was an inverse association between the level of linking social capital and prescription of psychiatric medications (except for anti-dementia drugs). The associations decreased, but remained significant, after accounting for age, sex, family income, marital status, country of birth, and education level (except for antidepressants). The OR for prescription of antipsychotics in the crude model was 1.65 (95% CI 1.53-1.78) and decreased, but remained significant (OR = 1.26; 95% CI 1.17-1.35), after adjustment for the individual-level sociodemographic variables.

CONCLUSIONS

Decision-makers should take into account the potentially negative effect of linking social capital on psychiatric disorders when planning sites of primary care centers and psychiatric clinics, as well as other kinds of community support for elderly patients with such disorders.

Modelling the co-occurrence of psychosis-like experiences and childhood sexual abuse

PURPOSE

Recurrent research evidence indicates that childhood sexual abuse (CSA) is associated with psychosis and psychosis-like experiences (PLEs). Many individuals however who have experienced psychosis have never been sexually abused in childhood and many individuals who have experienced CSA have never experienced psychosis.

METHOD

The current study sought to model the co-occurrence of CSA and PLEs using data from the Adult Psychiatric Morbidity Survey. Latent class analysis was employed to identify distinct classes of individuals in the general population who were characterised by the presence, co-occurrence or absence of PLEs and/or CSA. Multinomial logistic regression analysis was utilised to validate membership of classes characterised by both CSA and PLEs using a series of variables that have been proposed to delineate the co-occurrence of these phenomena.

RESULTS

Four hypothesised classes were identified, (1) a CSA-PLE co-occurrence class, (2) a PLE-only class, (3) a CSA-only class and (4) a CSA and PLE free baseline class. CSA-PLE co-occurrence was characterised by neurotic disorder, social isolation, adult sexual molestation and a history of post-traumatic stress disorder (PTSD). PLE occurrence in the absence of CSA was characterised by neurotic disorder, social isolation, a history of PTSD, childhood physical abuse, and uniquely by discrimination and non-sexual trauma post-16 years.

CONCLUSIONS

The findings indicated that a distinct group of individuals in the population was characterised by the co-occurrence of CSA and PLEs. In the absence of CSA, individuals who experienced PLEs were likely to endure a wide range of other, non-sexual, traumatic and adverse experiences. The CSA-PLE co-occurrence class and its associated psychosocial risk profile was discussed in relation to established trauma-based perspectives of psychosis and PLEs.