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

Risk and protective factors for severe mental disorders in Asia

Among 369 diseases and injuries, the years lived with disability (YLDs) and disability-adjusted life-years (DALYs) rates for severe mental illnesses (SMIs) are within the top 20 %. Research on risk and protective factors for SMIs is critically important, as acting on modifiable factors may reduce their incidence or postpone their onset, while early detection of new cases enables prompt treatment and improves prognosis. However, as most of the studies on these factors are from Western countries, the findings are not generalizable across ethnic groups. This led us to conduct a systematic review of the risk and protective factors for SMIs identified in Asian studies. There were common factors in Asian and Western studies and unique factors in Asian studies. In-depth knowledge of these factors could help reduce disability, and the economic and emotional burden of SMIs. We hope that this review will inform future research and policy-making on mental health in Asian countries.

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.

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.

Neighbourhood characteristics and the treated incidence rate of borderline personality pathology among young people

OBJECTIVE

The impact of the wider social environment, such as neighbourhood characteristics, has not been examined in the development of borderline personality disorder. This study aimed to determine whether the treated incidence rate of full-threshold borderline personality disorder and sub-threshold borderline personality disorder, collectively termed borderline personality pathology, was associated with the specific neighbourhood characteristics of social deprivation and social fragmentation.

METHOD

This study included young people, aged 15-24 years, who attended Orygen's Helping Young People Early programme, a specialist early intervention service for young people with borderline personality pathology, from 1 August 2000-1 February 2008. Diagnoses were confirmed using the Structured Clinical Interview for DSM-IV Personality Disorders, and census data from 2006 were used to determine the at-risk population and to obtain measures of social deprivation and fragmentation.

RESULTS

The study included 282 young people, of these 78.0% (n = 220) were female and the mean age was 18.3 years (SD = ±2.7). A total of 42.9% (n = 121) met criteria for full-threshold borderline personality disorder, and 57.1% (n = 161) had sub-threshold borderline personality disorder, defined as having three or four of the nine Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) borderline personality disorder criteria. There was more than a sixfold increase in the treated incidence rate of borderline personality pathology in the neighbourhoods of above average deprivation (Quartile 3) (incidence rate ratio = 6.45, 95% confidence interval: [4.62, 8.98], p < 0.001), and this was consistent in the borderline personality disorder sub-groups. This association was also present in the most socially deprived neighbourhood (Quartile 4) (incidence rate ratio = 1.63, 95% confidence interval: [1.10, 2.44]), however, only for those with sub-threshold borderline personality disorder. The treated incidence of borderline personality pathology increased incrementally with the level of social fragmentation (Quartile 3: incidence rate ratio = 1.93, 95% confidence interval: [1.37, 2.72], Quartile 4: incidence rate ratio = 2.38, 95% confidence interval: [1.77, 3.21]).

CONCLUSION

Borderline personality pathology has a higher treated incidence in the more socially deprived and fragmented neighbourhoods. These findings have implications for funding and location of clinical services for young people with borderline personality pathology. Prospective, longitudinal studies should examine neighbourhood characteristics as potential aetiological factors for borderline personality pathology.

The incidence of psychotic disorders in the Republic of Ireland: a systematic review

OBJECTIVES

Despite a substantial epidemiological literature on the incidence of psychotic disorders in Ireland, no systematic review has previously been undertaken. Such evidence can help inform understanding of need for psychosis care.

METHODS

We conducted a prospectively registered systematic review (PROSPERO: CRD42021245891) following PRISMA guidelines. We searched four databases (Medline, PsycInfo, Web of Science, Embase) for papers containing incidence data on non-organic psychotic disorders, in people 16-64 years, published between 1950 and 2021 in the general adult population. We conducted duplicate screening, risk of bias assessments, and extracted data to a standardised template. We undertook a narrative synthesis for each major diagnostic outcome. Random effects meta-analyses were conducted for comparisons with ≥5 incidence rates.

RESULTS

Our search yielded 1975 non-duplicate citations, of which 23 met inclusion criteria, containing incidence data ascertained between 1974 and 2016 (median study quality: 5/8; interquartile range: 4-6). Incidence of all psychotic disorders (N = 4 studies) varied from 22.0 (95%CI: 17.3-28.0) in Dublin to 34.1 per 100,000 person-years (95%CI: 31.0-37.5) in Cavan and Monaghan. The pooled incidence of schizophrenia (N = 6 studies, N = 8 settings) was 20.0 per 100,000 person-years, though with imprecision around this estimate (95%CI: 10.6-37.5; I2: 97.6%). Higher rates of most outcomes were observed in men. There was consistent evidence of raised rates in more deprived and fragmented social environments, but no clear pattern by rural-urban status.

CONCLUSIONS

Patterns of incidence of psychotic disorders in Ireland are broadly consistent with the wider literature from the Global North. Findings could help identify populations at higher risk of psychosis in Ireland.

The global burden of schizophrenia and the impact of urbanization during 1990-2019: An analysis of the global burden of disease study 2019

BACKGROUND AND HYPOTHESIS

The burden of schizophrenia is increasing. Assessing the global distribution of schizophrenia and understanding the association between urbanization factors and schizophrenia are crucial.

STUDY DESIGN

We conducted a two-stage analysis utilizing public data from GBD (global burden of disease) 2019 and the World Bank. First, the distribution of schizophrenia burden at the global, regional, and national levels as well as temporal trends was analyzed. Then, four composite indicators of urbanization (including demographic, spatial, economic, and eco-environment urbanization) were constructed from ten basic indicators. Panel data models were used to explore the relationship between urbanization indicators and the burden of schizophrenia.

RESULTS

In 2019, there were 23.6 million people with schizophrenia, an increase of 65.85% from 1990, and the country with the largest ASDR (age-standardized disability adjusted life years rate) was the United States of America, followed by Australia, and New Zealand. Globally, the ASDR of schizophrenia rose with the sociodemographic index (SDI). In addition, six basic urbanization indicators including urban population proportion, employment in industry/services proportion, urban population density, the population proportion in the largest city, GDP, and PM_2.5 concentration were positively associated with ASDR of schizophrenia, with the largest coefficients being urban population density. Overall, demographic, spatial, economic, and eco-environment urbanization all had positive effects on schizophrenia, and the estimated coefficients indicated that demographic urbanization was the most significant influence.

CONCLUSIONS

This study provided a comprehensive description of the global burden of schizophrenia and explored urbanization as a factor contributing to the variation in the burden of schizophrenia, and highlighted policy priorities for schizophrenia prevention in the context of urbanization.

A public early intervention approach to first-episode psychosis: Treated incidence over 7 years in the Emilia-Romagna region

AIM

To estimate the treated incidence of individuals with first-episode psychosis (FEP) who contacted the Emilia-Romagna public mental healthcare system (Italy); to examine the variability of incidence and user characteristics across centres and years.

METHODS

We computed the raw treated incidence in 2013-2019, based on FEP users aged 18-35, seen within or outside the regional program for FEP. We modelled FEP incidence across 10 catchment areas and 7 years using Bayesian Poisson and Negative Binomial Generalized Linear Models of varying complexity. We explored associations between user characteristics, study centre and year comparing variables and socioclinical clusters of subjects.

RESULTS

Thousand three hundred and eighteen individuals were treated for FEP (raw incidence: 25.3 / 100.000 inhabitant year, IQR: 15.3). A Negative Binomial location-scale model with area, population density and year as predictors found that incidence and its variability changed across centres (Bologna: 36.55; 95% CrI: 30.39-43.86; Imola: 3.07; 95% CrI: 1.61-4.99) but did not follow linear temporal trends or density. Centers were associated with different user age, gender, migrant status, occupation, living conditions and cluster distribution. Year was associated negatively with HoNOS score (R = -0.09, p < .001), duration of untreated psychosis (R = -0.12, p < .001) and referral type.

CONCLUSIONS

The Emilia-Romagna region presents a relatively high but variable incidence of FEP across areas, but not in time. More granular information on social, ethnic and cultural factors may increase the level of explanation and prediction of FEP incidence and characteristics, shedding light on social and healthcare factors influencing FEP.

Associations Between Cannabis Use, Polygenic Liability for Schizophrenia, and Cannabis-related Experiences in a Sample of Cannabis Users

BACKGROUND AND HYPOTHESIS

Risk for cannabis use and schizophrenia is influenced in part by genetic factors, and there is evidence that genetic risk for schizophrenia is associated with subclinical psychotic-like experiences (PLEs). Few studies to date have examined whether genetic risk for schizophrenia is associated with cannabis-related PLEs.

STUDY DESIGN

We tested whether measures of cannabis involvement and polygenic risk scores (PRS) for schizophrenia were associated with self-reported cannabis-related experiences in a sample ascertained for alcohol use disorders (AUDs), the Collaborative Study on the Genetics of Alcoholism (COGA). We analyzed 4832 subjects (3128 of European ancestry and 1704 of African ancestry; 42% female; 74% meeting lifetime criteria for an AUD).

STUDY RESULTS

Cannabis use disorder (CUD) was prevalent in this analytic sample (70%), with 40% classified as mild, 25% as moderate, and 35% as severe. Polygenic risk for schizophrenia was positively associated with cannabis-related paranoia, feeling depressed or anhedonia, social withdrawal, and cognitive difficulties, even when controlling for duration of daily cannabis use, CUD, and age at first cannabis use. The schizophrenia PRS was most robustly associated with cannabis-related cognitive difficulties (β = 0.22, SE = 0.04, P = 5.2e-7). In an independent replication sample (N = 1446), associations between the schizophrenia PRS and cannabis-related experiences were in the expected direction and not statistically different in magnitude from those in the COGA sample.

CONCLUSIONS

Among individuals who regularly use cannabis, genetic liability for schizophrenia-even in those without clinical features-may increase the likelihood of reporting unusual experiences related to cannabis use.

Ethnoracial discrimination and the development of suspiciousness symptoms in individuals at clinical high-risk for psychosis

BACKGROUND AND HYPOTHESIS

While individuals at clinical high-risk (CHR) for psychosis experience higher levels of discrimination than healthy controls, it is unclear how these experiences contribute to the etiology of attenuated positive symptoms. The present study examined the association of perceived discrimination with positive symptoms in a cohort from the North American Prodrome Longitudinal Study (NAPLS2). It predicted that CHR individuals will report higher levels of lifetime and past year perceived discrimination related to their race and ethnicity (ethnoracial discrimination) and that this form of discrimination will be significantly associated with baseline positive symptoms.

STUDY DESIGN

Participants included 686 CHR and 252 healthy controls. The present study examined data from the perceived discrimination (PD) scale, the Brief Core Schema Scale, and the Scale for the Psychosis-Risk Symptoms. Structural equation modeling was employed to examine whether negative schema of self and others mediated the relation of past year ethnoracial PD to baseline suspiciousness symptoms.

RESULTS

CHR individuals report higher levels of past year and lifetime PD compared to healthy controls. Lifetime ethnoracial PD was associated with suspiciousness and total positive symptoms. Negative schema of self and others scores partially mediated the relation of past year ethnoracial PD to suspiciousness, one of five positive symptom criteria for CHR.

CONCLUSIONS

For CHR individuals, past year ethnoracial discrimination was associated with negative beliefs about themselves and others, which was associated with suspiciousness. These findings contribute to an emerging literature characterizing the mechanisms by which discrimination contributes to the positive symptoms characterizing the CHR syndrome.

The impact of hazes on schizophrenia admissions and the synergistic effect with the combined atmospheric oxidation capacity in Hefei, China

OBJECTIVES

Currently, most epidemiological studies on haze focus on respiratory diseases, cardiovascular diseases, etc. However, the relationship between haze and mental health has not been adequately explored. The purpose of this study was to investigate the influence of hazes on schizophrenia admissions and to further explore the potential interaction effect with the combined atmospheric oxidative indices (O_x and O_x^wt).

METHODS

We collected 5328 cases during the cold season from 2013 to 2015 in Hefei, China. By integrating the Poisson Generalized Linear Models with the Distributed Lag Non-linear Models, the association between haze and schizophrenia admissions was evaluated. The interaction between hazes and two combined oxidation indexes was tested by stratifying hazes and O_x, and O_x^wt.

RESULTS

Haze was found to be significantly linked to an increased risk of hospitalization for schizophrenia, and a 9-day lag effect on schizophrenia (lag 3-lag 11), with the largest effect on lag 6 (RR = 1.080, 95% confidence interval (CI): 1.046-1.116). Males, females, and <40 y (people under 40 years old) were sensitive to hazes. Furthermore, in the stratified analysis, we found synergies between two combined oxidation indexes and hazes. The interaction relative risk (IRR) and relative excess risk due to interaction (RERI) between O_x and hazes were 1.170 (95% CI: 1.071-1.277) and 0.149 (95% CI: 0.045-0.253), respectively. For O_x^wt, the IRR and RERI were 1.179 (95% CI: 1.087-1.281) and 0.159 (95% CI: 0.056-0.263), respectively. It is noteworthy that this synergistic effect was significant in males and <40 y when examining the various subgroups in the interaction analysis.

CONCLUSIONS

Our findings suggest that exposure to haze significantly increases the risk of hospitalization for schizophrenia. More significant public health benefits can be obtained by prioritizing haze periods with high combined atmospheric oxidation capacity.

The association between social deprivation and the rate of identification of individuals at Ultra-High Risk for psychosis and transition to psychosis

BACKGROUND

There is a higher incidence of psychotic disorders in neighbourhoods of greater social deprivation. However, it is not known whether this represents a causal relationship, as the stage at which social deprivation exerts its influence on the development of psychotic disorders is yet to be elucidated. We aimed to investigate the association between neighbourhood-level social deprivation and the rate of identification of individuals at Ultra-High Risk for psychosis (UHR), as well as the risk of transition to psychosis in UHR individuals.

METHODS

The cohort included all young people aged 15 to 24 identified as UHR attending an Early Intervention clinic in northwestern Melbourne over a 5-year period (2012-2016). Australian census data were used to obtain the at-risk population and social deprivation information according to the postcode of residence. Levels of social deprivation were arranged into quartiles. Poisson regression was used to calculate rate ratios and Cox regression analysis determined hazard ratios.

RESULTS

Of the 461 young people identified as UHR, 11.1% (n = 49) lived in the most affluent neighbourhoods (Quartile 1) compared to 36.7% (n = 162) in the most deprived neighbourhoods (Quartile 4). There was a 35% higher rate of identification of young people who were UHR from the most deprived neighbourhoods (aIRR = 1.35, 95% CI [0.98, 1.86]). Over a median follow-up of approximately 10 months (308 days (IQR: 188-557), 17.5% (n = 77) were known to have transitioned to a full-threshold psychotic disorder. Residing in a neighbourhood of above average deprivation had a hazard ratio of 2.05 (95% CI [0.88, 4.80]) for risk of transition, when controlling for age, sex and substance use.

CONCLUSIONS

These findings provide more support that EI services should be funded as per the expected incidence of psychotic disorders.

Linking the Urban Environment and Health: An Innovative Methodology for Measuring Individual-Level Environmental Exposures

Environmental exposures (EE) are increasingly recognised as important determinants of health and well-being. Understanding the influences of EE on health is critical for effective policymaking, but better-quality spatial data is needed. This article outlines the theoretical and technical foundations used for the construction of individual-level environmental exposure measurements for the population of a northern English city, Bradford. The work supports 'Connected Bradford', an entire population database linking health, education, social care, environmental and other local government data over a period of forty years. We argue that our current understanding of environmental effects on health outcomes is limited both by methodological shortcomings in the quantification of the environment and by a lack of consistency in the measurement of built environment features. To address these shortcomings, we measure the environmental exposure for a series of different domains including air quality, greenspace and greenness, public transport, walkability, traffic, buildings and the built form, street centrality, land-use intensity, and food environments as well as indoor dwelling qualities. We utilise general practitioners' historical patient information to identify the precise geolocation and duration of a person's residence. We model a person's local neighbourhood, and the probable routes to key urban functions aggregated across the city. We outline the specific geospatial procedure used to quantify the environmental exposure for each domain and use the example of exposure to fast-food outlets to illustrate the methodological challenges in the creation of city and nationwide environmental exposure databases. The proposed EE measures will enable critical research into the relationship and causal links between the built environment and health, informing planning and policy-making.

Risk of first-episode psychosis in migrants to the Republic of Ireland

BACKGROUND

Migration is an established risk factor for developing a psychotic disorder in countries with a long history of migration. Less is known for countries with only a recent history of migration. This study aimed to determine the risk for developing a psychotic disorder in migrants to the Republic of Ireland.

METHODS

We included all presentations of first-episode psychosis over 8.5 years to the DETECT Early Intervention for psychosis service in the Republic of Ireland (573 individuals aged 18-65, of whom 22% were first-generation migrants). Psychotic disorder diagnosis relied on SCID. The at-risk population was calculated using census data, and negative binomial regression was used to estimate incidence rate ratios.

RESULTS

The annual crude incidence rate for a first-episode psychotic disorder in the total cohort was 25.62 per 100000 population at risk. Migrants from Africa had a nearly twofold increased risk for developing a psychotic disorder compared to those born in the Republic of Ireland (IRR = 1.83, 95% CI 1.11-3.02, p = 0.02). In contrast, migrants from certain Asian countries had a reduced risk, specifically those from China, India, Philippines, Pakistan, Malaysia, Bangladesh and Hong Kong (aIRR = 0.36, 95% CI 0.16-0.81, p = 0.01).

CONCLUSIONS

Further research into the reasons for this inflated risk in specific migrant groups could produce insights into the aetiology of psychotic disorders. This information should also be used, alongside other data on environmental risk factors that can be determined from census data, to predict the incidence of psychotic disorders and thereby resource services appropriately.

Psychosis and psychedelics: Historical entanglements and contemporary contrasts

Experiences of psychedelics and psychosis were deeply entangled in scientific practices in the mid-20th century, from uses of psychedelic drugs that could model psychosis, to detailed phenomenological comparisons of endogenous and drug-induced madness. After the moral panic of the 1960s shut down psychedelic research, however, these two phenomena became disentangled. In the decades following, the science of psychosis transformed, shedding the language of psychoanalysis, and adopting the new scientific veneer of psychiatry. Today, as psychedelic science re-emerges, the research programs surrounding psychosis and psychedelics now stand in stark contrast. Here, I look closely at how these research programs respond to questions related to what is worth measuring, what is worth investigating, and how we ought to respond to these experiences. This comparison reveals radically different assumptions and values that guide each research paradigm and shape clinical practice. While psychedelic research often includes scales that seek to capture experiences of mysticism, meaningfulness, and ego dissolution, research related to psychosis focuses on the measurement of pathological symptoms and functioning. Research into psychosis primarily seeks universal and reductionist causal explanations and interventions, while psychedelic research embraces the importance of set and setting in shaping unique experiences. Responses to psychedelic crisis involve warmth, compassion, and support, while responses to psychotic experiences often involve restraint, seclusion, and weapons. I argue that these differences contain important lessons for psychiatry. However, as psychedelic research struggles to meet regulatory requirements and fit within the paradigm of evidence-based medicine, these differences may quickly dissolve.

From scary places to therapeutic landscapes: Voices from the community of people living with schizophrenia

This article discusses how people living with schizophrenia experience, understand, and respond to their urban environment. Our study relies on experiential photo-voice data gathered with a sample of six people diagnosed with schizophrenia and living in non-institutional settings in Montréal, Canada, to identify how individuals in this community perceive the urban landscape. We adopt a therapeutic landscapes' framework that explores the urban fabric at three levels: physical, social, and symbolic. Research participants identified both health-denying and health-enhancing places within ordinary urban landscapes. Landscapes identified as health-denying are characterized by environmental stressors and loss of control, with construction sites an example highlighted by participants. Healing and restorative landscapes, as identified by participants, were physically attractive or quiet, socially safe and welcoming, and symbolically affirmative of one's identity, all factors worthy of further study. The findings are also policy-relevant: they suggest that people living with schizophrenia and their clinicians can develop strategies to make health-enhancing uses of urban landscapes; and that urban policies and practices can foster urban environments conducive to enhanced health and well-being, both for the community of people living with schizophrenia and the wider population of urban dwellers.

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

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

Gender differences in the association between environment and psychosis

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

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

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

Research on psychotic disorders in rural areas: Recent advances and ongoing challenges

BACKGROUND

Research on patients with chronic psychotic disorders in rural areas is scarce. Those patients may not receive adequate mental health care. Mental health disparities among rural and urban areas have been recognized.

AIMS

This review aims to present the most recent research on psychotic disorders in rural areas.

METHOD

We conducted a search in the PubMed and Scopus databases. The search involved articles published over the last decade (2011-2020). All types of research design were included, if studies had used a controlled group of urban patients and reported on the differences among rural/urban residents with psychotic disorders. The focus of the review was on outcome and treatment.

RESULTS

A total of 12 studies were included in this review. Most have been conducted in China or India. Reports from Western countries are rare. Outcome studies showed that employment rates are significantly higher in rural patients, as well as rates of marriage in women. It is not clear what is the impact of those outcomes on patients' lives. The finding of lower cost of psychotic disorders in some rural areas, should be viewed with scepticism. Studies on treatment aspects suggested that rural patients were less likely to receive antipsychotics, antipsychotic combination or clozapine. Those results were attributed to limited access to specialized treatment. When rural patients receive specialized community care they seem to have better outcomes than urban patients.

CONCLUSION

There is an ongoing, but still scarce research on patients with chronic psychotic disorders in rural areas. Researchers pointed out the impact of socioeconomic inequalities on outcome and treatment, and stressed the importance of minimizing mental health disparities. These findings may have potential implications for future research; for the introduction of accessible, locally based mental health services in rural areas; and for political initiatives that would address poverty and social inequalities.

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.

Particulate matter pollution associated with schizophrenia hospital re-admissions: a time-series study in a coastal Chinese city

Schizophrenia (SCZ) hospital re-admissions constitute a serious disease burden worldwide. Some studies have reported an association between air pollutants and hospital admissions for SCZ. However, evidence is scarce regarding the effects of ambient particulate matter (PM) on SCZ hospital re-admissions, especially in coastal cities in China. The purpose of this study was to examine whether PM affects the risk of SCZ hospital re-admission in the coastal Chinese city of Qingdao. Daily SCZ hospital re-admissions, daily air pollutants, and meteorological factors from 2015 to 2019 were collected. A quasi-Poisson generalized linear regression model combined with distributed lag non-linear model (DLNM) was applied to model the exposure-lag-response relationship between PM and SCZ hospital re-admissions. The relative risks (RRs) were estimated for an inter-quartile range (IQR) increase in PM concentrations. Subgroup analyses by age and gender were conducted to identify the vulnerable subgroups. There were 6220 SCZ hospital re-admissions during 2015-2019. The results revealed that PM, including PM₁₀ (particles with an aerodynamic diameter ≤10 μm), PM_c (particles >2.5 μm but <10 μm), and PM_2.5 (particles ≤2.5 μm), was positively correlated with SCZ hospital re-admissions. The strongest single-day effects all occurred on lag3 day, and the corresponding RRs were 1.07 (95% CI: 1.02-1.11) for PM₁₀, 1.03 (95% CI: 1.00-1.07) for PM_c, and 1.05 (95% CI: 1.01-1.09) for PM_2.5 per IQR increase. Stronger associations were observed in males and younger individuals (<45 years). Our findings suggest that PM exposure is associated with increased risk of SCZ hospital re-admission. Active intervention measures against PM exposure should be taken to reduce the risk of SCZ hospital re-admission, especially for males and younger individuals.

Stress and the Role of the Gut-Brain Axis in the Pathogenesis of Schizophrenia: A Literature Review

Schizophrenia is a severe neuropsychiatric disorder, and its etiology remains largely unknown. Environmental factors have been reported to play roles in the pathogenesis of schizophrenia, and one of the major environmental factors identified for this disorder is psychosocial stress. Several studies have suggested that stressful life events, as well as the chronic social stress associated with city life, may lead to the development of schizophrenia. The other factor is the gut–brain axis. The composition of the gut microbiome and alterations thereof may affect the brain and may lead to schizophrenia. The main interest of this review article is in overviewing the major recent findings on the effects of stress and the gut–brain axis, as well as their possible bidirectional effects, in the pathogenesis of schizophrenia.

Descriptive study of cases of schizophrenia in the Malian population

BACKGROUND

Schizophrenia is a relatively common disease worldwide with a point prevalence of around 5/1000 in the population. The aim of this present work was to assess the demographic, clinical, familial, and environmental factors associated with schizophrenia in Mali.

METHODS

This was a prospective descriptive study on a series of 164 patients aged at least 12 years who came for a follow-up consultation at the psychiatry department of the University Hospital Center (CHU) Point G in Mali between February 2019 and January 2020 for schizophrenia spectrum disorder as defined by DSM-5 diagnostic criteria.

RESULTS

Our results revealed that the male sex was predominant (80.5%). The 25-34 age group was more represented with 44.5%. The place of birth for the majority of our patients was the urban area (52.4%), which also represented the place of the first year of life for the majority of our patients (56.1%). We noted that the unemployed and single people accounted for 56.1 and 61% respectively. More than half of our patients 58.5% reported having reached secondary school level. With the exception of education level, there was a statistically significant difference in the distribution of demographic parameters. Familial schizophrenia cases accounted for 51.7% versus 49.3% for non-familial cases. The different clinical forms were represented by the paranoid form, followed by the undifferentiated form, and the hebephrenic form with respectively 34, 28 and 17.1%. We noted that almost half (48.8%) of patients were born during the cold season. Cannabis use history was not observed in 68.7% of the patients. The proportions of patients with an out-of-school father or an out-of-school mother were 51.2 and 64.2%, respectively.

CONCLUSION

The onset of schizophrenia in the Malian population has been associated with socio-demographic, clinical, genetic and environmental characteristics.

Epidemiological profile of psychiatric illnesses in the province of Taza, Morocco: case of a study on a schizophrenic sub-population in the Ibn Baja Hospital

Aim

The objective of this study is to assess the prevalence of major psychiatric disorders and to plot some characteristics of the schizophrenic sub-population in the study area.

Methods

We present the results of a retrospective study on psychiatric illnesses listed at the level of the psychiatric department at the Ibn Baja Hospital in the province of Taza (Morocco), involving a sample of 3803 patients aged 18 years and over between 2006 and 2016.

Results

The results obtained show that the average age of our sample is 33 ± 10.5 years and that schizophrenia is the most pronounced psychiatric disorder with a prevalence of 69.9%, followed by bipolar disorder (8.4%), manic state (8.3%), major depression (5.8%), epilepsy (3.7%), dementia (2.5%), and drug addiction (1.5%). The predominance of the workforce for all psychiatric disorders was significantly in favor of males (P = 0 .000) with an M/F sex ratio of 4.9. Most patients were from urban areas 77.1%, compared with 22.9% from rural areas, with a predominance of males (P<0.001). Schizophrenia disease is the most predominant in the region with a prevalence of 1.6% and affects 83% of men versus 17% of women with a M/F sex ratio value of 5.6 in favor of men (P = 0.000).

Conclusion

In our region of study, as everywhere else in the world, the prevalence of psychiatric diseases on the one hand, and schizophrenia on the other hand, seems to be worrying, thus requiring more vigilance on the part of public health workers in general and mental health workers.

Understanding urbanicity: how interdisciplinary methods help to unravel the effects of the city on mental health

Twenty-first century urbanization poses increasing challenges for mental health. Epidemiological studies have shown that mental health problems often accumulate in urban areas, compared to rural areas, and suggested possible underlying causes associated with the social and physical urban environments. Emerging work indicates complex urban effects that depend on many individual and contextual factors at the neighbourhood and country level and novel experimental work is starting to dissect potential underlying mechanisms. This review summarizes findings from epidemiology and population-based studies, neuroscience, experimental and experience-based research and illustrates how a combined approach can move the field towards an increased understanding of the urbanicity-mental health nexus.

Environmental Risk Factors in Bipolar Disorder and Psychotic Depression: A Systematic Review and Meta-Analysis of Prospective Studies

OBJECTIVE

The aim of this systematic review and meta-analysis was to study the association between specific environmental risk factors (ERF) and later development of Bipolar disorder and Psychotic depression.

METHODS

A systematic search of prospective studies was conducted in MEDLINE, EMBASE and PsycINFO databases, and supplemented by hand searching, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (registration number: CRD42018092253). Selected ERF included: pre-/peri-natal factors-paternal age at birth, maternal infection, obstetric complications, perinatal stress; early childhood factors-urbanicity at birth, childhood infection, childhood adversity; later life factors-substance misuse, ethnic minority and migration, urbanicity later in life, stressful life events, and traumatic head injury. Pooled effect sizes of the association between these ERF and affective psychoses were calculated from systematically selected studies. When studies examining each ERF were insufficient for meta-analysis, results were presented narratively.

RESULTS

Forty-six studies were included for quantitative analyses among selected ERF for affective psychosis, with significant association found for paternal age >40 years (OR 1.17, 95%CI 1.12-1.23), early (OR 1.52, 95%CI 1.07-2.17) and late (OR 1.32, 95%CI 1.05-1.67) gestational age, childhood adversity (OR 1.33, 95%CI 1.18-1.50), substance misuse (OR 2.87, 95%CI 1.63-5.50), and being from an ethnic minority (OR 1.99, 95%CI 1.39-2.84).

CONCLUSIONS

These results suggest some shared environmental load between non-affective and affective psychosis, implying generalized risks for psychosis rather than for specific diagnostic categories. Nonetheless, published studies for some ERF in the affective psychoses are scarce, and further longitudinal studies are needed.

The Self and Its Nature: A Psychopathological Perspective on the Risk-Reducing Effects of Environmental Green Space for Psychosis

Epidemiological studies have shown that environmental green space contributes to the reduction of psychosis incidence in the population. Clarifying the psychological and neuro-functional mechanisms underlying the risk-decreasing effects of green surroundings could help optimize preventive environmental interventions. This perspective article specifically aims to open a new window on the link between environmental green space and psychosis by considering its core psychopathological features. Psychotic disorders, such as schizophrenia, are essentially characterized by self-disturbances. The psychological structure of the self has been described as a multidimensional phenomenon that emerges from the reciprocal interaction with the environment through intrinsic and extrinsic self-processes. The intrinsic self refers to the experience of mental activity and environmental information as inherently related to one’s own person, which involves self-referential processing, self-reflection, memory, interoception, and emotional evaluation. The extrinsic self refers to sensorimotor interactions with the environment and the sense of agency, that is, the experience of being the source of one’s own actions and the multisensory consequences thereof. In psychosis, anomalous self-processing has been related to a functional fragmentation of intrinsic and extrinsic self-processes and related brain networks. Moreover, evidence from cognitive neuroscience suggests that green space could have beneficial effects on self-related processing. Based on the literature, it could be hypothesized that self-processing is involved in mediating the beneficial effects of green space for psychosis. Considering the multidimensionality of the self, it is proposed that urban green space design aimed at improving mental health ideally impacts the complexity of self-facets and thus restores the individual’s self.

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

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

Identification of risk factors for involuntary psychiatric hospitalization: using environmental socioeconomic data and methods of machine learning to improve prediction

BACKGROUND

The purpose of this study was to identify factors associated with a high risk of involuntary psychiatric in-patient hospitalization both on the individual level and on the level of mental health services and the socioeconomic environment that patients live in.

METHODS

The present study expands on a previous analysis of the health records of 5764 cases admitted as in-patients in the four psychiatric hospitals of the Metropolitan City of Cologne, Germany, in the year 2011 (1773 cases treated under the Mental Health Act and 3991 cases treated voluntarily). Our previous analysis had included medical, sociodemographic and socioeconomic data of every case and used a machine learning-based prediction model employing chi-squared automatic interaction detection (CHAID). Our current analysis attempts to improve the previous one through (1) optimizing the machine learning procedures (use of a different type of decision-tree prediction model (Classification and Regression Trees (CART) and application of hyperparameter tuning (HT)), and (2) the addition of patients' environmental socioeconomic data (ESED) to the data set.

RESULTS

Compared to our previous analysis, model fit was improved. Main diagnoses of an organic mental or a psychotic disorder (ICD-10 groups F0 and F2), suicidal behavior upon admission, admission outside of regular service hours and absence of outpatient treatment prior to admission were confirmed as powerful predictors of detention. Particularly high risks were shown for (1) patients with an organic mental disorder, specifically if they were retired, admitted outside of regular service hours and lived in assisted housing, (2) patients with suicidal tendencies upon admission who did not suffer from an affective disorder, specifically if it was unclear whether there had been previous suicide attempts, or if the affected person lived in areas with high unemployment rates, and (3) patients with psychosis, specifically those who lived in densely built areas with a large proportion of small or one-person households.

CONCLUSIONS

Certain psychiatric diagnoses and suicidal tendencies are major risk factors for involuntary psychiatric hospitalization. In addition, service-related and environmental socioeconomic factors contribute to the risk for detention. Identifying modifiable risk factors and particularly vulnerable risk groups should help to develop suitable preventive measures.

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.

Assessment of the Role of IQ in Associations Between Population Density and Deprivation and Nonaffective Psychosis

IMPORTANCE

Being born or raised in more densely populated or deprived areas is associated with increased risk of nonaffective psychosis in adulthood, but few studies to date have examined the role of general cognitive ability in these associations.

OBJECTIVE

To investigate whether lower IQ contributed to the association between population density or deprivation and nonaffective psychosis (mediation) and whether these associations were stronger in people with lower IQ (effect modification).

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study evaluated a population-based sample of men born in Sweden from January 1, 1982, to December 31, 1988, and conscripted into military service at 18 years of age. Data were collected from January 1, 1982, to December 31, 2016, and analyzed from May 1 to December 31, 2018.

EXPOSURES

Continuous measures of small area-level population density (persons per square kilometer) and socioeconomic deprivation at birth. Deprivation was based on area-level social, criminal, and unemployment data. IQ was assessed during conscription at 18 years of age (mean [SD] IQ, 100 [15]).

MAIN OUTCOMES AND MEASURES

First diagnosis of International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, nonaffective psychosis from 18 years of age until December 31, 2016, recorded in the National Patient Register.

RESULTS

The study sample included a total of 227 429 men who were classified as at risk of psychosis from 18 years of age until the end of follow-up. Of these, 1596 men (0.7%) were diagnosed with nonaffective psychosis. After adjustments for confounders, odds of nonaffective psychosis increased per 1-SD increase in population density (odds ratio [OR], 1.07; 95% CI, 1.04-1.14) and deprivation (OR, 1.09; 95% CI, 1.02-1.13) at birth. IQ was negatively associated with deprivation after adjustments (effect estimate per 1-SD increase in deprivation: -0.70 points; 95% CI, -0.78 to -0.62 points) but not with population density. In mediation analyses, based on the potential outcome framework, 23% (95% CI, 17%-49%) of the total effect of deprivation on nonaffective psychosis was mediated by IQ. IQ did not modify associations between deprivation or population density and nonaffective psychosis.

CONCLUSIONS AND RELEVANCE

These findings suggest that being born in more deprived neighborhoods may partly increase risk of nonaffective psychosis through subsequent effects on cognitive development, consistent with the wider literature on neurodevelopmental delays associated with psychotic disorder. Identifying factors in deprived environments that give rise to this process could inform public health strategies to prevent nonaffective psychosis.

Validity and utility of Hierarchical Taxonomy of Psychopathology (HiTOP): I. Psychosis superspectrum

The Hierarchical Taxonomy of Psychopathology (HiTOP) is a scientific effort to address shortcomings of traditional mental disorder diagnoses, which suffer from arbitrary boundaries between psychopathology and normality, frequent disorder co-occurrence, heterogeneity within disorders, and diagnostic instability. This paper synthesizes evidence on the validity and utility of the thought disorder and detachment spectra of HiTOP. These spectra are composed of symptoms and maladaptive traits currently subsumed within schizophrenia, other psychotic disorders, and schizotypal, paranoid and schizoid personality disorders. Thought disorder ranges from normal reality testing, to maladaptive trait psychoticism, to hallucinations and delusions. Detachment ranges from introversion, to maladaptive detachment, to blunted affect and avolition. Extensive evidence supports the validity of thought disorder and detachment spectra, as each spectrum reflects common genetics, environmental risk factors, childhood antecedents, cognitive abnormalities, neural alterations, biomarkers, and treatment response. Some of these characteristics are specific to one spectrum and others are shared, suggesting the existence of an overarching psychosis superspectrum. Further research is needed to extend this model, such as clarifying whether mania and dissociation belong to thought disorder, and explicating processes that drive development of the spectra and their subdimensions. Compared to traditional diagnoses, the thought disorder and detachment spectra demonstrated substantially improved utility: greater reliability, larger explanatory and predictive power, and higher acceptability to clinicians. Validated measures are available to implement the system in practice. The more informative, reliable and valid characterization of psychosis-related psychopathology offered by HiTOP can make diagnosis more useful for research and clinical care.

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.

Urban remediation: a new recovery-oriented strategy to manage urban stress after first-episode psychosis

PURPOSE

Urban living is a major risk factor for psychosis. Considering worldwide increasing rates of urbanization, new approaches are needed to enhance patients' wellbeing in cities. Recent data suggest that once psychosis has emerged, patients struggle to adapt to urban milieu and that they lose access to city centers, which contributes to isolation and reduced social contacts. While it is acknowledged that there are promising initiatives to improve mental health in cities, concrete therapeutic strategies to help patients with psychosis to better handle urban stress are lacking. We believe that we should no longer wait to develop and test new therapeutic approaches.

METHOD

In this review, we first focus on the role of urban planning, policies, and design, and second on possible novel therapeutic strategies at the individual level. We review how patients with psychosis may experience stress in the urban environment. We then review and describe a set of possible strategies, which could be proposed to patients with the first-episode psychosis.

RESULTS

We propose to group these strategies under the umbrella term of 'urban remediation' and discuss how this novel approach could help patients to recover from their first psychotic episode.

CONCLUSION

The concepts developed in this paper are speculative and a lot of work remains to be done before it can be usefully proposed to patients. However, considering the high prevalence of social withdrawal and its detrimental impact on the recovery process, we strongly believe that researchers should invest this new domain to help patients regain access to city centers.

How environments get to the skin: biosensory ethnography as a method for investigating the relation between psychosis and the city

Epidemiological research in psychiatry has established robust evidence of the link between urban living and psychosis, but the situated experience of the city, as well as the precise ecology of psychosis remain largely unexplored. In this context, the aim of this paper is to discuss the productive potential of a ‘re-vitalized’ biosocial geographical thinking and researching on urban mental health. We do so through a methodological proposition. First, we discuss the need for a biosocial approach to the city/psychosis nexus and argue that a broader biological view, beyond epigenetics and neurosciences and a more precise investigation of ‘the social’ need to be developed. Second, a telling and recurring motto of recent reflections on biosocial processes is to understand how the environment or the social ‘gets under the skin’. We suggest examining a specific place in this pathway, the skin itself. This leads us to expose a methodology using electrodermal activity (EDA), combined with ethnographic observations and interviews, as a strategy for analysing ecological processes in psychosis. In doing so, we discuss the potential of ‘biosensory ethnographies’ in studies of urban mental health and more broadly as a biosocial approach to the geography of health.

Chronic stress, structural exposures and neurobiological mechanisms: A stimulation, discrepancy and deprivation model of psychosis

Chronic stress exposure has been established as a key vulnerability factor for developing psychotic disorders, including schizophrenia. A structural, or systems level perspective, has often been lacking in conceptualizations of chronic stress for psychotic disorders. The current review thus identified three subtypes of structural exposures. Stimulation exposures included urban environments, population density and crime exposure, with intermediary mechanisms of lack of safety and high attentional demands. Underlying neural mechanisms included threat neural circuits. Discrepancy exposures included environmental ethnic density, income inequality, and social fragmentation, with intermediary mechanisms of lack of belonging and social exclusion, and neural mechanisms including the oxytocin system. Deprivation exposures included environments lacking socioeconomic, educational, or material resources, with intermediary mechanisms of lack of needed environmental enrichment, and underlying neural mechanisms of over-pruning and protracted PFC development. Delineating stressor etiology at the systems level is a necessary step in reducing barriers to effective interventions and health policy.

Early intervention services for psychosis in Ireland: are we there yet?

Early intervention in psychosis (EIP) services are now a priority for Ireland’s Health Service Executive (HSE). A Model of Care for EIP services has been completed after wide consultation. It has just been launched by the Minister for Mental Health and the aim now is to roll out EIP services throughout the country. The Model of Care outlines the rational, configuration, resources, governance, and quality assurance required to operate EIP services. Two models are recommended. The first is a Hub & Spoke service model for rural and smaller urban areas. The second is a Stand-Alone service model for large urban and metropolitan areas. Introducing EIP services is going to be a challenge but there are plenty of good examples overseas. They have been shown to greatly enhance local services’ ability to meet the needs of people developing psychotic disorders. They bring with them better outcomes, service satisfaction and cost savings.

Psychosocial Stress Induces Schizophrenia-Like Behavior in Mice With Reduced MMP-9 Activity

Understanding gene-environment interactions in the pathogenesis of schizophrenia remains a major research challenge. Matrix metalloproteinase-9 (MMP-9) has been previously implicated in the pathophysiology of schizophrenia. In the present study, adolescent Mmp-9 heterozygous mice, with a genetically lower level of MMP-9, were subjected to resident-intruder psychosocial stress for 3 weeks and then examined in behavioral tests that evaluated cognitive deficits and positive- and negative-like symptoms of schizophrenia. Cognitive and positive symptoms in unstressed Mmp-9 heterozygous mice were unaffected by stress exposure, whereas negative symptoms were manifested only after stress exposure. Interestingly, negative symptoms were ameliorated by treatment with the antipsychotic drug clozapine. We describe a novel gene × environment interaction mouse model of schizophrenia. Lower MMP-9 levels in the brain might be a risk factor for schizophrenia that, in combination with environmental factors (e.g., psychosocial stress), may evoke schizophrenia-like symptoms that are sensitive to antipsychotic treatment.

Incidence of treated first episode psychosis from an Australian early intervention service and its association with neighbourhood characteristics

OBJECTIVES

Psychotic disorder incidence varies geographically and is associated with neighbourhood characteristics, including social deprivation, population density, unemployment, social capital or social fragmentation. Yet it is not known whether these findings are applicable to Australia's unique geography. This study aimed to determine whether the incidence of first episode psychosis (FEP) varies according to neighbourhood characteristics in an Australian cohort.

METHOD

This study included all young people, aged 15 to 24, with an FEP who attended Orygen Youth Health in Melbourne, from a geographically defined catchment area encompassing Northern and Western Melbourne, over a 44-month period. Neighbourhood demographic data was collected from the 2011 Australian National Census. Negative binomial regression was used to determine incidence rate ratios controlled for age, sex and migrant status.

RESULTS

A total of 747 young people had an FEP during the 44-month study period and 722 were included in this study. Of these, 58.0% were males and 67.9% had a non-affective psychotic disorder; the mean age of the cohort was 19.1 years. The incidence of FEP in young people aged 15 to 24 in the catchment area was 123.2 per 100,000 person-years. There was a higher incidence of FEP in neighbourhoods of greatest social deprivation (IRR = 1.65, CI = 1.06-2.51, p = .02), highest unemployment (IRR = 1.56, CI = 1.04-2.35, p = .03) and above average social fragmentation (IRR = 1.42, CI = 1.02-1.97, p = .04), when controlled for age, sex and migrant status.

CONCLUSIONS

This study highlights variation in psychotic disorder incidence and the need for this disparity to be reflected in appropriate resource allocation.

Is urban living good for mental health?

PURPOSE OF REVIEW

The questions of urban living, mental health and well-being are complex issues correlated to many interacting factors. The purpose of this review is to provide data on mental health challenges of urban life and perspectives to address these challenges.

RECENT FINDINGS

Urbanization may cause mental health problems, such as psychotic experiences, depression and stress-related disorders, particularly in vulnerable individuals. Challenges of urban living are even greater in developing countries, because of other urgent problems these countries are facing. New findings identified distinct neural mechanisms for an established environmental risk factor, linking the urban environment to social stress processing. Nature-based solutions may be helpful in preventing mental disorders and in alleviating psychological symptoms.

SUMMARY

The data of impact of urban living on mental health are still controversial and mechanism of association is unclear. Urban living may be related to biological or social/environmental factors or both. Most probably, urbanicity has a synergistic effect with genetic vulnerability. Interdisciplinary and intersectoral actions are needed to meet urban living challenges, such as providing access to green space and mental health services, decrease of poverty, homelessness and emerging problems of immigration to cities.

Forging successful partnerships in psychosis research: lessons from the Cavan–Monaghan First Episode Psychosis Study

Embedding psychosis research within community mental services is highly desirable from several perspectives but can be difficult to establish and sustain, especially when the clinical service has a rural location at a distance from academic settings with established research expertise. In this article, we share the experience of a successful partnership in psychosis research between a rural Irish mental health service and the academic department of a Dublin medical school that has lasted over 30 years. We describe the origins and evolution of this relationship, the benefits that accrued and the challenges encountered, from the overlapping perspectives of the academic department, the mental health service and psychiatric training. We discuss the potential learning that arose from the initiative, particularly for national programme planning for early intervention in psychosis, and we explore the opportunities for enhanced training, career development and professional reward that can emerge from this type of partnership.

The Cavan-Monaghan First Episode Psychosis Study (CAMFEPS): arbitrary diagnostic boundaries across the gene–environment interface and within evolving models of care

As research into psychotic illness evolves along established lines, insights are emerging that deviate from those lines and challenge more fundamentally our understanding. On the background of a new generation of studies on first-episode psychosis, investigations across the gene–environment interface and the intersection with ‘normal’ human mentation heighten these concerns. Using findings from the Cavan-Monaghan First Episode Psychosis Study (CAMFEPS) as an exemplar, we here review the complexity of these challenges from the perspective of this real-world setting. They range from trans-diagnostic epidemiology and clinical characterisation, through molecular genetics, social milieu, developmental pathobiology and functional outcome across arbitrary diagnostic boundaries, to the evidence base for early intervention and more radical conceptualisations and structures for provision of mental health care.

120th Anniversary of the Kraepelinian Dichotomy of Psychiatric Disorders

PURPOSE OF REVIEW

Emil Kraepelin, in 1899, proposed a dichotomy of psychiatric disorders into "dementia praecox," further called schizophrenia, and "manisch-depressives Irresein," now conceptualized as a bipolar disorder. The purpose of the review is to show both similarities and differences between disorders involved in this dichotomy, speaking for and against the idea.

RECENT FINDINGS

On the molecular genetic side, there are data for both a genetic overlap and genetic differences between these two illnesses. Among pharmacological treatment, lithium, valproates, and carbamazepine present evidence for Kraepelinian dichotomy while atypical antipsychotics speak against this. The recent results for similarities and differences in the immune system, cognitive functions, and neurodevelopmental mechanisms have also been presented and discussed. As of 2019, the Kraepelinian dichotomy has been still partly valid although the results of recent clinical, neurobiological, and pharmacological studies provided a large number of data for an intermediate space between schizophrenia and bipolar disorder.

Enhanced cerebellar myelination with concomitant iron elevation and ultrastructural irregularities following prenatal exposure to ambient particulate matter in the mouse

Accumulating evidence indicates the developing central nervous system (CNS) is a target of air pollution toxicity. Epidemiological reports increasingly demonstrate that exposure to the particulate matter (PM) fraction of air pollution during neurodevelopment is associated with an increased risk of neurodevelopmental disorders (NDDs) such as autism spectrum disorder (ASD). These observations are supported by animal studies demonstrating prenatal exposure to concentrated ambient PM induces neuropathologies characteristic of ASD, including ventriculomegaly and aberrant corpus callosum (CC) myelination. Given the role of the CC and cerebellum in ASD etiology, this study tested whether prenatal exposure to concentrated ambient particles (CAPs) produced pathological features in offspring CC and cerebella consistent with ASD. Analysis of cerebellar myelin density revealed male-specific hypermyelination in CAPs-exposed offspring at postnatal days (PNDs) 11-15 without alteration of cerebellar area. Atomic absorption spectroscopy (AAS) revealed elevated iron (Fe) in the cerebellum of CAPs-exposed female offspring at PNDs 11-15, which connects with previously observed elevated Fe in the female CC. The presence of Fe inclusions, along with aluminum (Al) and silicon (Si) inclusions, were confirmed at nanoscale resolution in the CC along with ultrastructural myelin sheath damage. Furthermore, RNAseq and gene ontology (GO) enrichment analyses revealed cerebellar gene expression was significantly affected by sex and prenatal CAPs exposure with significant enrichment in inflammation and transmembrane transport processes that could underlie observed myelin and metal pathologies. Overall, this study highlights the ability of PM exposure to disrupt myelinogenesis and elucidates novel molecular targets of PM-induced developmental neurotoxicity.

Is the serious ambient air pollution associated with increased admissions for schizophrenia?

BACKGROUND

Much of the research has shown an increased risk of psychiatric disorders in association with elevated exposure to air pollution, such as NO₂, PM₁₀ and SO₂. However, few studies investigate the effect of these air pollution on the risk of schizophrenia admissions and the lagged effect among different subgroups.

METHODS

A distributed lag non-linear model (DLNM) combined with a Poisson generalized linear regression model was applied to analyzing the relationship between schizophrenia and air pollution. At first, according to the minimum AIC criterion, we discussed the lagged effect of NO₂, PM₁₀ and SO₂ for 5 days, 4 days and 10 days, respectively. Then, we chose benchmarks as references (25th) to conduct comparisons with different levels of pollutant concentrations (90th and 95th). All patients were retrieved from the Psychiatric Hospital of TongLing (n = 3469) from January 2014 to December 2016. Daily air pollutants and meteorological data were collected from the Chinese national air quality monitoring (NAQM) and Meteorological Bureau. Subgroup analysis was conducted by gender (male and female), age (0-19 ages, 20-39 ages, 40-59 ages and ≥ 60 ages) and occupation (farmer, worker and unemployed).

RESULTS

The effects of the three air pollutants were statistically significant to schizophrenia admissions. We found that NO₂ and PM₁₀ have short-term effects of 4 days and 3 days (NO₂: lag 0-4 RR, 1.84(95% CI: 1.49-2.27), PM₁₀: lag 0-3 RR, 1.97(95%CI: 1.57-2.36)), respectively. SO₂ had longer effects for 10 days (SO₂: lag 0-10 RR, 2.93(95%CI: 2.10-4.10)). Additionally, it significantly increased the risk of schizophrenia episode in subjects with male, 20-59 ages, farmer and worker.

CONCLUSION

We find adverse effects of ambient air pollutants on schizophrenia admissions in TongLing, China, which may provide valuable information for the policy makers and local health authorities to conduct effective intervention of air pollution on schizophrenia.

The prevalence and psychosocial risk factors for psychotic-like experiences (PLE) among high school students in Jakarta

INTRODUCTION

The prevalence of psychotic-like experiences (PLE) in general population is moderately high (5%-8%), although the prevalence of psychotic disorder is considerably low (˂1%). Amid the urgency to understand the underlying factors of psychotic disorder and PLE, most research tend to focus on genetic factors. However, numerous recent works suggested increasing importance of non-genetic factors. This study aims to investigate the prevalence of PLE and any psychosocial variables that contribute to any occurrence of PLE among adolescent in Jakarta.

METHODS

This is a school based cross-sectional study that was carried out in early 2017. A total sample of 623 high school students from five schools in Jakarta were selected by using multistage random sampling. Psychotic experience was measured using Psychotic-Like Experiences Questionnaire. Multiple psychosocial variables proposed as predictor model for PLE were examined using multivariate regression.

RESULTS

Our final result showed 20.6% prevalence of PLE among high school students in Jakarta. The proposed psychosocial risk model (consisting of violence exposure, parental communication pattern, peer and conduct problems, social comparison, parental attachment, loneliness, and bullying) contributed to explain 16.3% of the occurrence of PLE (R square: .163).

DISCUSSION

The prevalence of PLE in this population was considerably high. Cultural factors such as paranormal beliefs are assumed to contribute to the high prevalence of PLE among high school students. The quite low contribution score of psychosocial model proposed in predicting the phenomenon of PLE shows that further research is needed to explore more variables that can be better predictors of PLE.

Search for protective factors for psychosis - a population-based sample with special interest in unaffected individuals with parental psychosis

AIM

To find factors that are associated with not having psychotic illness in a prospective general population sample, with a special interest in individuals with parental psychosis.

METHODS

Data from the Northern Finland Birth Cohort 1966 (n = 10 458) and several registers were used to detect individuals with and without parental psychosis. Altogether, 594 persons had parent(s) with psychosis and 48 of them also had psychosis subsequently. Variables related to pregnancy and birth, family and childhood, health and habits in adolescence, school performance and physical activity were studied to identify determinants of unaffected status among individuals with and without parental psychosis.

RESULTS

In the parental psychosis group, the unaffected persons had more likely a mother who was non-depressed during pregnancy, and who worked outside the home or studied than among those who developed psychosis.

CONCLUSIONS

Protective factors for psychosis were surprisingly few in this sample. These factors were related to the mother's non-depressed mood and the mother's work outside the home or studies. This could relate to better health and functioning of a mother. This work highlights the need for more research on protective factors for psychosis in order to identify methods for prevention of psychosis.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Is there a link between air pollution and mental disorders?

Several studies have demonstrated the association between air pollution and different medical conditions including respiratory and cardiovascular diseases. Air pollutants might have a role also in the etiology of mental disorders in the light of their toxicity on central nervous system. Purpose of the present manuscript was to review and summarize available data about an association between psychiatric disorders and air pollution. A research in the main database sources has been conducted to identify relevant papers about the topic. Different air pollutants and in particular PM and nitric oxides have been associated with poor mental health; long exposition to PM_2.5 has been associated with an increased risk of new onset of depressive symptoms (Cohen's effect size d: 0.05-0.81), while increased concentration of nitric dioxide in summer with worsening of existing depressive conditions (Cohen's effect size d: 0.05-1.77). However, the interpretation of these finding should take into account the retrospective design of most of studies, different periods of observations, confounding factors such as advanced age or medical comorbidity. Further studies with rigorous methodology are needed to confirm the results of available literature about this topic.

Sensorimotor gating deficits in "two-hit" models of schizophrenia risk factors

Genetic and environmental models of neuropsychiatric disease have grown exponentially over the last 20years. One measure that is often used to evaluate the translational relevance of these models to human neuropsychiatric disease is prepulse inhibition of startle (PPI), an operational measure of sensorimotor gating. Deficient PPI characterizes several neuropsychiatric disorders but has been most extensively studied in schizophrenia. It has become a useful tool in translational neuropharmacological and molecular genetics studies because it can be measured across species using almost the same experimental parameters. Although initial studies of PPI in rodents were pharmacological because of the robust predictive validity of PPI for antipsychotic efficacy, more recently, PPI has become standard common behavioral measures used in genetic and neurodevelopmental models of schizophrenia. Here we review "two hit" models of schizophrenia and discuss the utility of PPI as a tool in phenotyping these models of relevant risk factors. In the review, we consider approaches to rodent models of genetic and neurodevelopmental risk factors and selectively review "two hit" models of gene×environment and environment×environment interactions in which PPI has been measured.