Is there evidence that social class at birth increases risk of psychosis? A systematic review

Using latent class analysis to investigate enduring effects of intersectional social disadvantage on long-term vocational and financial outcomes in the 20-year prospective Chicago Longitudinal Study

BACKGROUND

Class and social disadvantage have long been identified as significant factors in the etiology and epidemiology of psychosis. Few studies have explicitly examined the impact of intersecting social disadvantage on long-term employment and financial independence.

METHODS

We applied latent class analysis (LCA) to 20-year longitudinal data from participants with affective and non-affective psychosis (n = 256) within the Chicago Longitudinal Research. LCA groups were modeled using multiple indicators of pre-morbid disadvantage (parental social class, educational attainment, race, gender, and work and social functioning prior to psychosis onset). The comparative longitudinal work and financial functioning of LCA groups were then examined.

RESULTS

We identified three distinct latent classes: one comprised entirely of White participants, with the highest parental class and highest levels of educational attainment; a second predominantly working-class group, with equal numbers of Black and White participants; and a third with the lowest parental social class, lowest levels of education and a mix of Black and White participants. The latter, our highest social disadvantage group experienced significantly poorer employment and financial outcomes at all time-points, controlling for diagnosis, symptoms, and hospitalizations prior to baseline. Contrary to our hypotheses, on most measures, the two less disadvantaged groups did not significantly differ from each other.

CONCLUSIONS

Our analyses add to a growing literature on the impact of multiple forms of social disadvantage on long-term functional trajectories, underscoring the importance of proactive attention to sociostructural disadvantage early in treatment, and the development and evaluation of interventions designed to mitigate ongoing social stratification.

The effect of non-medical cannabis retailer proximity on use of mental health services for psychotic disorders in Ontario, Canada

BACKGROUND

Cannabis is associated with the onset and persistence of psychotic disorders. Evidence suggests that accessibility of substances is associated with an increased risk of use-related harms. We sought to examine the effect of residing in proximity to non-medical cannabis retailers on the prevalence of health service use for psychosis.

METHODS

We conducted a cross-sectional study using linked health administrative data, and used geospatial analyses to determine whether people in Ontario, Canada (aged 14-60 years) resided within walking (1.6 km) or driving (5.0 km) distance of non-medical cannabis retailers (open as of February-2020). We identified outpatient visits, emergency department (ED) visits, and hospitalizations for psychotic disorders between 01-April-2019 and 17-March-2020. We used zero-inflated Poisson regression models and gamma generalized linear models to estimate the association between cannabis retailer proximity and indicators of health service use.

RESULTS

Non-medical cannabis retailers were differentially located in areas with high levels of marginalization and pre-existing health service use for psychosis. People residing within walking or driving distance of a cannabis retailer had a higher rate of psychosis-related outpatient visits, ED visits, and hospitalizations, compared to people living outside these areas. This effect was stronger among those with no prior service use for psychosis.

CONCLUSIONS

Proximity to a non-medical cannabis retailer was associated with higher health service use for psychosis, even after adjustment for prior health service use. These findings suggest that opening of non-medical cannabis retailers could worsen the burden of psychosis on mental health services in areas with high-risk populations.

Stress, Environment and Early Psychosis

Existing literature provides extended evidence of the close relationship between stress dysregulation, environmental insults, and psychosis onset. Early stress can sensitize genetically vulnerable individuals to future stress, modifying their risk for developing psychotic phenomena. Neurobiological substrate of the aberrant stress response to hypothalamic-pituitary-adrenal axis dysregulation, disrupted inflammation processes, oxidative stress increase, gut dysbiosis, and altered brain signaling, provides mechanistic links between environmental risk factors and the development of psychotic symptoms. Early-life and later-life exposures may act directly, accumulatively, and repeatedly during critical neurodevelopmental time windows. Environmental hazards, such as pre- and perinatal complications, traumatic experiences, psychosocial stressors, and cannabis use might negatively intervene with brain developmental trajectories and disturb the balance of important stress systems, which act together with recent life events to push the individual over the threshold for the manifestation of psychosis. The current review presents the dynamic and complex relationship between stress, environment, and psychosis onset, attempting to provide an insight into potentially modifiable factors, enhancing resilience and possibly influencing individual psychosis liability.

The association of social inequality with the onset, persistence, and progression of psychotic experiences along the extended psychosis phenotype: a 6-year follow-up study in a community-based sample

PURPOSE

This paper aims to investigate associations between early childhood and current indicators of socioeconomic inequality and the onset (incident), persistence and progression (increase in severity) of psychotic experiences (PEs) in a longitudinal follow-up of a community-based population.

METHODS

Households in the metropolitan area of Izmir, Turkey were contacted in a multistage clustered probability sampling frame, at baseline (T1, n = 4011) and at 6-year follow-up (T2, n = 2185). Both at baseline and follow-up, PEs were assessed using Composite International Diagnostic Interview 2.1. The associations between baseline socioeconomic features and follow-up PEs were analysed using logistic regression models. Indicators of social inequality included income, educational level, current socioeconomic status (SES), social insurance, the area resided, ethnicity, parental educational level, and SES at birth.

RESULTS

The risk of onset of PEs was significantly higher in lower education, lower SES, and slum-semi-urban areas. The persistence of PEs was significantly associated with the lowest levels of education and current SES, and rural residency. Persistent PEs were significantly and negatively associated with paternal SES at birth. Progression of PEs was significantly higher among respondents with educational achievements lower than university level and lower levels of SES, who have no social insurance and who reside in slum-semi-urban areas. Parental education and paternal SES at birth were not associated with the persistence of PEs.

CONCLUSION

Indicators of social inequality (low education, low SES, low income, and poverty in the neighbourhood) were associated with the onset and persistence of PEs and progression along the extended psychosis phenotype. The early indicators seem to have a modest life-long impact on the psychosis phenotype.

Examining delusional ideation: Relationships with race and socioeconomic status

Race and socioeconomic status (SES) are commonly cited as risk factors for psychosis and psychotic-like experiences (PLEs). However, few studies have investigated the relationships between race and SES with specific domains of PLEs. Specifically, little work has examined the relationships between race and SES with delusional ideation, severity (preoccupation, conviction, distress), and delusional themes. Using cross-sectional, general population data (N = 727) from the Nathan Kline Institute-Rockland (NKI-Rockland) database, we investigated racial differences in delusional ideation and severity between Black and White participants, including differences in delusional themes. Then, we investigated SES's relationship with delusional thinking and the interaction between race and SES on delusional thinking. Black American participants endorsed higher delusional ideation with stronger severity than White Americans. A significant interaction between race and delusional theme revealed that Black Americans endorse significantly more delusional ideation in themes of grandiosity, religiosity, and referential-guilt. Black Americans endorse greater delusional severity in grandiose and religious ideations. Black Americans endorse stronger preoccupation and conviction - but not distress-in their referential-guilt ideation. SES was not significantly associated with delusional thinking, nor did SES moderate the significant relationships between race and delusional ideation. These results illuminate the clear racial disparity that exist in delusional ideation within a general population, which did not extend to SES in this dataset. Future work should investigate deeper into the contributory factors to these racial disparities, particularly whether they are based in psychological and/or cultural differences or are the result of assessment/measurement bias.

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.

Schizotypal traits in a large sample of high-school and university students from Tunisia: correlates and measurement invariance of the arabic schizotypal personality questionnaire across age and sex

BACKGROUND

The main goal of the present study was to examine the characteristics of schizotypal traits and their correlations with genetic (i.e., family history of mental illness), demographic (i.e., age, sex), environmental (e.g., income, urbanicity, tobacco/alcohol/cannabis use), and psychological (i.e., personal history of mental illness other than psychosis) factors in Tunisian high-school and university students. Our secondary goal was to contribute the literature by examining the factor structure and factorial invariance of the Arabic Schizotypal Personality Questionnaire (SPQ) across sex and age (adolescents [12-18 years] vs. young adults [18-35 years]) groups.

METHOD

This was a cross-sectional study involving 3166 students: 1160 (36.6%) high-school students (53.0% females, aged 14.9 ± 1.8); and 2006 (63.4%) university students (63.9% females, aged 21.8 ± 2.3). All students were asked to complete a paper-and-pencil self-administered questionnaire containing sociodemographic characteristics as well as the Arabic version of the SPQ.

RESULTS

The total sample yielded total SPQ scores of 24.1 ± 16.6 out of 74. The SPQ yielded good composite reliability as attested by McDonald's omega values ranging from .68 to .80 for all nine subscales. Confirmatory Factor Analysis indicated that fit of the 9-factor model of SPQ scores was acceptable. This model is invariant (at the configural, metric and structural levels) across sex and age. Except for "Odd or eccentric behavior", all schizotypy features were significantly higher among female students compared to males. Multivariable analyses showed that female sex, being a university student, lowest family incomes, tobacco use, and having a personal history of psychiatric illness were significantly associated with higher positive, negative and disorganized schizotypy subscales scores.

CONCLUSION

Future research still needs to confirm our findings and investigate the contribution of the identified factors in the development of clinical psychosis. We can also conclude that the Arabic SPQ is appropriate for measuring and comparing schizotypy across age and sex in clinical and research settings. These findings are highly relevant and essential for ensuring the clinical utility and applicability of the SPQ in cross-cultural research.

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.

Low status, humiliation, dopamine and risk of schizophrenia

The social defeat hypothesis of schizophrenia, which proposes that the chronic experience of outsider status or subordinate position leads to increased striatal dopamine activity and thereby to increased risk, has been criticized. The aims of this paper are to improve the definition of defeat and to integrate the social defeat hypothesis with the neurodevelopmental hypothesis. Marmot advanced the idea that low status is pathogenic in that it is associated with a lack of social participation and a lack of autonomy. Given the similarity with outsider status and subordinate position, we re-define social defeat as low status. From this new perspective it is also likely that pre-schizophrenic impairments (of neurodevelopmental origin or not) are pathogenic in that they contribute to low status. The effect of low status may be enhanced by repeated exposure to humiliation, but few studies have measured this variable. Since most individuals exposed to low status do not develop schizophrenia, we propose that this risk factor increases the risk of disorder in the presence of a poor homeostatic control of dopamine neurons in midbrain and dorsal striatum. This is consistent with studies of healthy subjects which report a negative association between low socio-economic status and dopamine D2/D3 receptor availability in the dorsal striatum. In this new version of the social defeat hypothesis we propose that the combination of low status, repeated humiliation and poor homeostatic control of dopamine neurons in midbrain and dorsal striatum leads to increased striatal dopamine activity and thereby to an increased risk of schizophrenia.

Risk of psychosis in illicit amphetamine users: a 10 year retrospective cohort study

QUESTION

Amphetamine use is a risk factor for psychosis, which imposes a substantial burden on society. We aimed to investigate the incidence of psychosis associated with illicit amphetamine use and whether rehabilitation treatments could influence the psychosis risk.

STUDY SELECTION AND ANALYSIS

A retrospective cohort study was conducted using the population based Taiwan Illicit Drug Issue Database (TIDID) and the National Health Insurance Research Database (NHIRD), from 2007 to 2016. We identified 74 601 illicit amphetamine users as the amphetamine cohort and 2 98 404 subjects as the non-amphetamine cohort. The incidence rate of newly diagnosed psychosis was the main outcome. Cox proportional hazards models were applied to assess the effects of amphetamine, and the Kaplan-Meier method was used to estimate the cumulative psychosis incidence curves.

FINDINGS

Illicit amphetamine users were 5.28 times more likely to experience psychosis than those without illicit drug use records. The risk was higher for subjects with multiple arrests for amphetamine use. A greater hazard ratio (HR) magnitude was observed in female patients. We also observed a significant decrease in the risk of psychosis in patients receiving rehabilitation treatments during deferred prosecution (adjusted HR 0.74, 95% CI 0.61 to 0.89).

CONCLUSIONS

Illicit amphetamine use was associated with an increased incidence of psychosis. The risk was identified across all age groups, particularly in women and in those arrested multiple times, and was inversely correlated with rehabilitation treatments for amphetamine misuse.

Migration history and risk of psychosis: results from the multinational EU-GEI study

BACKGROUND

Psychosis rates are higher among some migrant groups. We hypothesized that psychosis in migrants is associated with cumulative social disadvantage during different phases of migration.

METHODS

We used data from the EUropean Network of National Schizophrenia Networks studying Gene-Environment Interactions (EU-GEI) case-control study. We defined a set of three indicators of social disadvantage for each phase: pre-migration, migration and post-migration. We examined whether social disadvantage in the pre- and post-migration phases, migration adversities, and mismatch between achievements and expectations differed between first-generation migrants with first-episode psychosis and healthy first-generation migrants, and tested whether this accounted for differences in odds of psychosis in multivariable logistic regression models.

RESULTS

In total, 249 cases and 219 controls were assessed. Pre-migration (OR 1.61, 95% CI 1.06-2.44, p = 0.027) and post-migration social disadvantages (OR 1.89, 95% CI 1.02-3.51, p = 0.044), along with expectations/achievements mismatch (OR 1.14, 95% CI 1.03-1.26, p = 0.014) were all significantly associated with psychosis. Migration adversities (OR 1.18, 95% CI 0.672-2.06, p = 0.568) were not significantly related to the outcome. Finally, we found a dose-response effect between the number of adversities across all phases and odds of psychosis (⩾6: OR 14.09, 95% CI 2.06-96.47, p = 0.007).

CONCLUSIONS

The cumulative effect of social disadvantages before, during and after migration was associated with increased odds of psychosis in migrants, independently of ethnicity or length of stay in the country of arrival. Public health initiatives that address the social disadvantages that many migrants face during the whole migration process and post-migration psychological support may reduce the excess of psychosis in migrants.

Exploring the intersection of the microbiome and the developing brain: Impacts on schizophrenia risk

Recent findings show that the perinatal maternal and infant microbiomes have profound potential to impact long term health outcomes. Of particular interest are the ways in which the microbiome influences the developing brain during one of its most critical windows. Schizophrenia and psychosis risk are strongly connected to disruptions in perinatal neurodevelopment. In this review we present an overview of critical aspects in development of both the microbiome and brain, discuss their overlap, and consider what role the microbiome plays in schizophrenia risk during the perinatal window. Considering this, we discuss ways in which expecting and new mothers may reduce offspring schizophrenia risk.

Low income and schizophrenia risk: a narrative review

Despite decades of research, the precise etiology of schizophrenia is not fully understood. Ample evidence indicates that the disorder derives from a complex interplay of genetic and environmental factors during vulnerable stages of brain maturation. Among the plethora of risk factors investigated, stress, pre- and perinatal insults, and cannabis use have been repeatedly highlighted as crucial environmental risk factors for schizophrenia. Compelling findings from population-based longitudinal studies suggest low income as an additional risk factor for future schizophrenia diagnosis, but underlying mechanisms remain unclear. In this narrative review, we 1) summarize the literature in support of a relationship between low (parental) income and schizophrenia risk, and 2) explore the mediating role of chronic stress, pre- and perinatal factors, and cannabis use as established risk factors for schizophrenia. Our review describes how low income facilitates the occurrence and severity of these established risk factors and thus contributes to schizophrenia liability. The broadest influence of low income was identified for stress, as low income was found to be associated with exposure to a multitude of severe psychological and physiological stressors. This narrative review adds to the growing literature reporting a close relationship between income and mental health.

Effects of socioeconomic status in cognition of people with schizophrenia: results from a Latin American collaboration network with 1175 subjects

BACKGROUND

Cognition heavily relies on social determinants and genetic background. Latin America comprises approximately 8% of the global population and faces unique challenges, many derived from specific demographic and socioeconomic variables, such as violence and inequality. While such factors have been described to influence mental health outcomes, no large-scale studies with Latin American population have been carried out. Therefore, we aim to describe the cognitive performance of a representative sample of Latin American individuals with schizophrenia and its relationship to clinical factors. Additionally, we aim to investigate how socioeconomic status (SES) relates to cognitive performance in patients and controls.

METHODS

We included 1175 participants from five Latin American countries (Argentina, Brazil, Chile, Colombia, and Mexico): 864 individuals with schizophrenia and 311 unaffected subjects. All participants were part of projects that included cognitive evaluation with MATRICS Consensus Cognitive Battery and clinical assessments.

RESULTS

Patients showed worse cognitive performance than controls across all domains. Age and diagnosis were independent predictors, indicating similar trajectories of cognitive aging for both patients and controls. The SES factors of education, parental education, and income were more related to cognition in patients than in controls. Cognition was also influenced by symptomatology.

CONCLUSIONS

Patients did not show evidence of accelerated cognitive aging; however, they were most impacted by a lower SES suggestive of deprived environment than controls. These findings highlight the vulnerability of cognitive capacity in individuals with psychosis in face of demographic and socioeconomic factors in low- and middle-income countries.

Economic strain, parental education and psychotic experiences among college students in the United States: Findings from the Healthy Minds Study 2020

AIM

Socioeconomic status (SES) is linked to psychosis, and much can be learned by examining how various indicators of SES-specifically economic strain and intergenerational transfer of resources-are related to sub-threshold psychotic experiences among college students.

METHODS

Using data from the Healthy Minds Survey (September 2020-December 2020), we used multivariable logistic regression models to examine the associations between five SES indicators and 12-month psychotic experiences, adjusting for age, gender and race/ethnicity. We also examined the count of predictors and psychotic experiences.

RESULTS

Each indicator of economic strain was associated with greater odds of psychotic experiences. In particular, increasing levels of financial stress (current, childhood and pandemic-related) were associated with greater odds of psychotic experiences in a dose-response fashion. Food insecurity was associated with double the odds of psychotic experiences. In terms of intergenerational transfer of resources, having either one or no parents who attended college was associated with significantly greater odds of having psychotic experiences, when compared with having both parents who attended college. Examining all predictors in the same model, only childhood and current financial stress and food insecurity were significantly associated with psychotic experiences. The count of predictors was significantly associated with greater odds of having psychotic experiences in a dose-dependent fashion.

CONCLUSIONS

Among college students, economic strain and intergenerational transfer of resources were associated with recent psychotic experiences, highlighting the importance of economic interventions targeting young adults to influence risk for psychosis.

Structural Racism and Inequities in Incidence, Course of Illness, and Treatment of Psychotic Disorders Among Black Americans

Psychotic disorders (e.g., schizophrenia, schizoaffective disorder) are a leading cause of morbidity and premature mortality and an overlooked health inequity in the United States. European data indicate inequities in incidence, severity, and treatment of psychotic disorders, particularly for Black communities, that appear to be primarily attributable to social adversities. The dominant US narrative is that any observed differences are primarily a result of clinician bias and misdiagnosis. We propose that employing the framework of structural racism will prompt European and US research to converge and consider the multifaceted drivers of inequities in psychotic disorders among Black Americans. In particular, we describe how historical and contemporary practices of (1) racialized policing and incarceration, and (2) economic exploitation and disinvestment, which are already linked to other psychiatric disorders, likely contribute to risks and experiences of psychotic disorders among Black Americans. This framework can inform new strategies to (1) document the role of racism in the incidence, severity, and treatment of psychotic disorders; and (2) dismantle how racism operates in the United States, including defunding the police, abolishing carceral systems, and redirecting funds to invest in neighborhoods, housing, and community-based crisis response and mental health care. (Am J Public Health. 2022;112(4):624-632. https://doi.org/10.2105/AJPH.2021.306631).

Development of the Korea-Polyenvironmental Risk Score for Psychosis

OBJECTIVE

Comprehensive understanding of polyenvironmental risk factors for the development of psychosis is important. Based on a review of related evidence, we developed the Korea Polyenvironmental Risk Score (K-PERS) for psychosis. We investigated whether the K-PERS can differentiate patients with schizophrenia spectrum disorders (SSDs) from healthy controls (HCs).

METHODS

We reviewed existing tools for measuring polyenvironmental risk factors for psychosis, including the Maudsley Environmental Risk Score (ERS), polyenviromic risk score (PERS), and Psychosis Polyrisk Score (PPS). Using odds ratios and relative risks for Western studies and the "population proportion" (PP) of risk factors for Korean data, we developed the K-PERS, and compared the scores thereon between patients with SSDs and HCs. In addition, correlation was performed between the K-PERS and Positive and Negative Syndrome Scale (PANSS).

RESULTS

We first constructed the "K-PERS-I," comprising five factors based on the PPS, and then the "K-PERS-II" comprising six factors based on the ERS. The instruments accurately predicted participants' status (case vs. control). In addition, the K-PERS-I and -II scores exhibited significant negative correlations with the negative symptom factor score of the PANSS.

CONCLUSION

The K-PERS is the first comprehensive tool developed based on PP data obtained from Korean studies that measures polyenvironmental risk factors for psychosis. Using pilot data, the K-PERS predicted patient status (SSD vs. HC). Further research is warranted to examine the relationship of K-PERS scores with clinical outcomes of psychosis and schizophrenia.

Maternal infection exposure and the risk of psychosis in the offspring: A systematic review and meta-analysis

The relationship between maternal infection exposure and the risk of psychosis in the offspring is inconsistent. We systematically assessed this relationship. Unrestricted searches of the PubMed and Embase databases were conducted, with an end date of February 1, 2020, to identify relevant studies that met predetermined inclusion criteria. Random-effects models were adopted to estimate the overall relative risk. Twenty-three observational studies were included in the analysis. The results showed that mothers who had a history of infection during pregnancy experienced a significantly increased risk of developing psychosis in offspring (OR = 1.25, 95% confidence interval (CI): 1.1-1.41; P = 0.001). Sensitivity and subgroup analyses yielded consistent results. For specific pathogens, the risk of developing psychosis in offspring was increased among mothers with herpes simplex virus 2 (HSV-2) exposure (OR, 1.32; 95% CI, 1.09-1.6; P = 0.004). However, other maternal-specific pathogen exposures were not significantly associated with the risk of psychosis in offspring. No evidence of publication bias was observed. Although evidence of heterogeneity should be carefully evaluated, our findings suggest that maternal infection exposure may be associated with a greater risk of psychosis in the offspring.

Predicting psychosis-spectrum diagnoses in adulthood from social behaviors and neighborhood contexts in childhood

Research showing that risk for schizophrenia, bipolar disorder with psychosis, and other psychosis-spectrum diagnoses in adulthood is multidetermined has underscored the necessity of studying the additive and interactive factors in childhood that precede and predict future disorders. In this study, risk for the development of psychosis-spectrum disorders was examined in a 2-generation, 30-year prospective longitudinal study of 3,905 urban families against a sociocultural backdrop of changing economic and social conditions. Peer nominations of aggression, withdrawal, and likeability and national census information on neighborhood-level socioeconomic disadvantage in childhood, as well as changes in neighborhood socioeconomic conditions over the lifespan, were examined as predictors of diagnoses of schizophrenia, bipolar disorder, and other psychosis-spectrum disorders in adulthood relative to developing only nonpsychotic disorders or no psychiatric disorders. Individuals who were both highly aggressive and highly withdrawn were at greater risk for other psychosis-spectrum diagnoses when they experienced greater neighborhood disadvantage in childhood or worsening neighborhood conditions over maturation. Males who were highly aggressive but low on withdrawal were at greater risk for schizophrenia diagnoses. Childhood neighborhood disadvantage predicted both schizophrenia and bipolar diagnoses, regardless of childhood social behavior. Results provided strong support for multiple-domain models of psychopathology, and suggest that universal preventive interventions and social policies aimed at improving neighborhood conditions may be particularly important for decreasing the prevalence of psychosis-spectrum diagnoses in the future.

How often do US-based schizophrenia papers published in high-impact psychiatric journals report on race and ethnicity?: A 20-year update of Lewine and Caudle (1999)

BACKGROUND

Racial and ethnic disparities have been clearly documented in schizophrenia studies, but it is unclear how much research attention they receive among US-based studies published in high-impact journals.

AIMS

The current paper updates Lewine and Caudle's (1999) and Chakraborty and Steinhauer's (2010) works, which quantified how frequently schizophrenia studies included information on race and ethnicity in their analyses.

METHOD

We examined all US-based papers on schizophrenia-spectrum, first-episode psychosis, and clinical high-risk groups, published between 2014 to 2016 in four major psychiatric journals: American Journal of Psychiatry, Journal of the American Medical Association - Psychiatry, Schizophrenia Bulletin, and Schizophrenia Research.

RESULTS

Of 474 US-based studies, 62% (n = 295) reported analyses by race or ethnicity as compared to 20% in Lewine and Caudle's (1999) study. The majority of papers (59%) reported sample descriptions, a 42% increase from Lewine and Caudle's (1999) study. Additionally, 47% matched or compared the racial/ethnic composition of primary study groups and 12% adjusted for race (e.g., as a covariate). However, only 9% directly analyzed racial and/or ethnic identity in relation to the primary topic of the paper.

CONCLUSIONS

While schizophrenia studies report analyses by race and ethnicity more frequently than 20 years ago, there remains a strong need for systematic, nuanced research on this topic. The authors offer recommendations for how to conceptualize and report upon race and ethnicity in schizophrenia research.

Early environmental factors and somatic comorbidity in schizophrenia and nonschizophrenic psychoses: A 50-year follow-up of the Northern Finland Birth Cohort 1966

Background.

We studied the cumulative incidence of physical illnesses, and the effect of early environmental factors (EEFs) on somatic comorbidity in schizophrenia, in nonschizophrenic psychosis and among nonpsychotic controls from birth up to the age of 50 years.

Methods.

The sample included 10,933 members of the Northern Finland Birth Cohort 1966, of whom, 227 had schizophrenia and 205 had nonschizophrenic psychosis. Diagnoses concerning physical illnesses were based on nationwide registers followed up to the end of 2016 and classified into 13 illness categories. Maternal education and age, family type at birth and paternal socioeconomic status were studied as EEFs of somatic illnesses.

Results.

When adjusted by gender and education, individuals and especially women with nonschizophrenic psychosis had higher risk of morbidity in almost all somatic illness categories compared to controls, and in some categories, compared to individuals with schizophrenia. The statistically significant adjusted hazard ratios varied from 1.27 to 2.42 in nonschizophrenic psychosis. Regarding EEFs, single-parent family as the family type at birth was a risk factor for a higher somatic score among men with schizophrenia and women with nonschizophrenic psychosis. Maternal age over 35 years was associated with lower somatic score among women with nonschizophrenic psychosis.

Conclusions.

Persons with nonschizophrenic psychoses have higher incidence of somatic diseases compared to people with schizophrenia and nonpsychotic controls, and this should be noted in clinical work. EEFs have mostly weak association with somatic comorbidity in our study.

Migration and psychosis: a meta-analysis of incidence studies

BACKGROUND

The aims of this meta-analysis are (i) to estimate the pooled relative risk (RR) of developing non-affective psychotic disorder (NAPD) and affective psychotic disorder (APD) among migrants and their children; (ii) to adjust these results for socioeconomic status (SES); (iii) to examine the sources of heterogeneity that underlie the risk of NAPD.

METHODS

We included population-based incidence studies that reported an age-adjusted RR with 95% confidence interval (CI) published 1 January 1977-12 October 2017 and used a random-effects model.

RESULTS

We retrieved studies performed in Europe (n = 43), Israel (n = 3), Canada (n = 2) and Australia (n = 1). The meta-analysis yielded a RR, adjusted for age and sex, of 2.13 (95% CI 1.99-2.27) for NAPD and 2.94 (95% CI 2.28-3.79) for APD. The RRs diminished, but persisted after adjustment for SES. With reference to NAPD: a personal or parental history of migration to Europe from countries outside Europe was associated with a higher RR (RR = 2.94, 95% CI 2.63-3.29) than migration within Europe (RR = 1.88, 95% 1.62-2.18). The corresponding RR was lower in Israel (RR = 1.22; 0.99-1.50) and Canada (RR = 1.21; 0.85-1.74). The RR was highest among individuals with a black skin colour (RR = 4.19, 95% CI 3.42-5.14). The evidence of a difference in risk between first and second generation was insufficient.

CONCLUSIONS

Positive selection may explain the low risk in Canada, while the change from exclusion to inclusion may do the same in Israel. Given the high risks among migrants from developing countries in Europe, social exclusion may have a pathogenic role.

Psychopathology, cognition and outcome in Dutch and immigrant first-episode psychosis patients

AIM

The primary aim was to examine differences in baseline symptom expression, neurocognition, social cognition and psychosocial functioning between Dutch, first-generation immigrants and second-generation immigrants with a first-episode psychosis (FEP). The secondary aim was to examine functional and symptomatic change and between-group differences at 12-months follow-up. Associations between migration, baseline characteristics and outcome were explored.

METHODS

Forty-six Dutch, 56 second-generation- and 60 first-generation immigrant patients completed baseline measures for 6 symptom dimensions (positive symptoms, negative symptoms, neurocognitive functioning, social cognitive functioning, excitement and emotional distress) and 5 domains of psychosocial functioning (general functioning, work and study, relationships, self-care and disturbing behaviour). Functioning and psychotic symptoms were assessed at baseline and 12-months follow-up. ANCOVA and t tests were used to assess between-group differences. General linear models were used to explore within-group differences. Backward-regression was used to explore predictors of outcome.

RESULTS

Levels of positive symptoms, excitement and emotional distress did not differ between groups at baseline or follow-up. Dutch patients had lower levels of negative symptoms than both immigrant groups at follow-up. On neurocognition and social cognition, Dutch performed better than second-generation immigrants, who in turn performed better than first-generation immigrants. Psychosocial functioning across all domains at baseline and at 12-months follow-up was similar across groups. Baseline levels of general psychosocial functioning and income were the strongest predictors of outcome at follow-up.

CONCLUSIONS

Psychosocial functioning and symptom profiles are comparable between Dutch, first-generation immigrant and second-generation immigrant FEP patients, excluding neurocognitive and social cognitive deficits. A range of baseline characteristics predicted outcome.

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.

What causes psychosis? An umbrella review of risk and protective factors

Psychosis is a heterogeneous psychiatric condition for which a multitude of risk and protective factors have been suggested. This umbrella review aimed to classify the strength of evidence for the associations between each factor and psychotic disorders whilst controlling for several biases. The Web of Knowledge database was searched to identify systematic reviews and meta-analyses of observational studies which examined associations between socio-demographic, parental, perinatal, later factors or antecedents and psychotic disorders, and which included a comparison group of healthy controls, published from 1965 to January 31, 2017. The literature search and data extraction followed PRISMA and MOOSE guidelines. The association between each factor and ICD or DSM diagnoses of non-organic psychotic disorders was graded into convincing, highly suggestive, suggestive, weak, or non-significant according to a standardized classification based on: number of psychotic cases, random-effects p value, largest study 95% confidence interval, heterogeneity between studies, 95% prediction interval, small study effect, and excess significance bias. In order to assess evidence for temporality of association, we also conducted sensitivity analyses restricted to data from prospective studies. Fifty-five meta-analyses or systematic reviews were included in the umbrella review, corresponding to 683 individual studies and 170 putative risk or protective factors for psychotic disorders. Only the ultra-high-risk state for psychosis (odds ratio, OR=9.32, 95% CI: 4.91-17.72) and Black-Caribbean ethnicity in England (OR=4.87, 95% CI: 3.96-6.00) showed convincing evidence of association. Six factors were highly suggestive (ethnic minority in low ethnic density area, second generation immigrants, trait anhedonia, premorbid IQ, minor physical anomalies, and olfactory identification ability), and nine were suggestive (urbanicity, ethnic minority in high ethnic density area, first generation immigrants, North-African immigrants in Europe, winter/spring season of birth in Northern hemisphere, childhood social withdrawal, childhood trauma, Toxoplasma gondii IgG, and non-right handedness). When only prospective studies were considered, the evidence was convincing for ultra-high-risk state and suggestive for urbanicity only. In summary, this umbrella review found several factors to be associated with psychotic disorders with different levels of evidence. These risk or protective factors represent a starting point for further etiopathological research and for the improvement of the prediction of psychosis.

Gene-environment interaction as a predictor of early adjustment in first episode psychosis

BACKGROUND

This study aims to explore the gene-environment interaction hypothesis applied to pre-symptomatic neurodevelopmental phenotypes of first episode psychosis (FEP), that is, genetic factors might increase vulnerability to the effects of environmental adverse conditions occurring at later stages of development.

METHODS

We constructed a schematic 'two-hit' model, with Val/Val homozygosity for the catechol-O-methyltransferase (COMT) Val158Met polymorphism as the 'first hit' and history of obstetric complications and parental socioeconomic status as 'second hits'. Early adjustment, measured using the Premorbid Adjustment Scale, was considered the main outcome. The study population comprised 221 adolescents and adults with FEP and 191 sex- and age-matched controls.

RESULTS

The interaction between the Val/Val COMT genotype and a positive history of obstetric complications plus low parental socioeconomic status was significantly associated with poorer early adjustment. These results were observed both in FEP individuals and in controls, and remained significant after controlling for age, sex, and diagnosis.

CONCLUSIONS

Individuals carrying Val/Val seem to be more sensitive to the synergistic effect of environmental factors acting early in neurodevelopment, which leads to vulnerability phenotypes such as impaired early adjustment.

Early psychosis in central Vietnam: A longitudinal study of short-term functional outcomes and their predictors

BACKGROUND

Few longitudinal studies have investigated the functional outcomes of individuals with recent-onset psychotic illness in low- and middle-income countries.

AIMS

To investigate short-term functional remission and its predictors in a central Vietnamese sample.

METHODS

A naturalistic 6-month prospective cohort study recruited 79 patients of public health facilities who had experienced a first episode of schizophrenia or related illness in the past 18 months. Individuals and their family members were interviewed using standardised assessments of community functioning, symptoms, treatment, demographics and various psychosocial variables. Rates of functional remission (i.e. no or minimal impairment) were calculated based on rigorous, culturally appropriate criteria. Generalised estimating equations were used to explore predictors of remission.

RESULTS

Rates of global functional remission were 28% at baseline and 53% at follow-up. In individual functional domains, remission was least common for occupational activities, intermediate for relationships and relatively common for daily living activities. Global functional remission was significantly associated with absence of negative and cognitive symptoms, average or better household economic status and unimpaired premorbid functioning.

CONCLUSION

Remission rates appeared similar to those seen in many international intervention studies. However, individuals from poor households had markedly unfavourable outcomes, suggesting the need for community-based interventions targeting low-socioeconomic status (SES) groups.

Incidence of schizophrenia among migrants in the Netherlands: a direct comparison of first contact and longitudinal register approaches

PURPOSE

To estimate the effect of selective sampling on first contact (FC) studies of the relation between migration and schizophrenia.

METHODS

We compared the FC method directly with a more inclusive longitudinal psychiatric register (LPR) method, by letting both methods estimate age and sex adjusted incidence rate ratios (IRR) in the population of The Hague aged 20-54 years, for the three largest migrant groups (first and second generation Caribbean, Turkish, and Moroccan) relative to the native Dutch population.

RESULTS

Both methods found that the adjusted IRR was higher for migrants than for native Dutch [all migrants IRR = 1.70 (95% Cl 1.30-2.21) for the LPR method and 1.91 (95% Cl 1.15-3.25) for the FC]. The IRR for Moroccans was significantly lower in the LPR [IRR 2.69 (95% 2.10-3.41)] than in the FC study [4.81 (3.41-6.68)]. The FC method was relatively more inclusive for migrants presenting at earlier ages or with shorter durations of prior treatment (DPT) than the native Dutch. This resulted in differential sampling and artificially higher IRRs for Moroccan and, to a lesser extent, Turkish migrants.

CONCLUSION

We confirm that the incidence of schizophrenia is raised twofold for migrants compared to nonmigrants. Using the LPR method, however, IRR estimates were less pronounced for most migrant groups than in a high quality FC study conducted in the same population. The FC method may overestimate the risk of schizophrenia for migrant groups who seek first mental health at a relatively younger age, or who present directly with schizophrenia.

Socioeconomic status at birth and risk for first episode psychosis in rural Ireland: Eliminating the features of urbanicity in the Cavan-Monaghan First Episode Psychosis Study (CAMFEPS)

BACKGROUND

There is a paucity of research on the relationship between social environment at birth and risk for psychosis in rural settings. This study examined the relationship between individual- and neighbourhood-level socioeconomic indicators proximal to the time of birth and risk for a first psychotic episode in a rural context using a prospective dataset of unusual epidemiological completeness.

METHODS

A matched case-control design was used. 186 cases were identified from the Cavan-Monaghan First Episode Psychosis Study (CAMFEPS) and 679 age- and sex-matched controls from the same rural setting were identified and analysed for relationships with individual and neighbourhood-level socioeconomic indicators at the level of Electoral Divisions.

RESULTS

While neither the distribution nor the ordinal scale of parental social class differed between cases and controls, logistic regression revealed both parental social class III and increasing level of rurality to be associated (p≤0.05) with reduced risk for affective psychosis. There was a prominent relationship (p<0.001) between lower parental social class and older age at first presentation [mean age at first presentation for all psychoses: social class I, 22.8; social class VI, 44.3].

CONCLUSIONS

These findings indicate modest effects of individual- and neighbourhood-level socioeconomic indicators and risk for psychosis by place at birth within a rural environment. Thus, these factors are not confined to large urban settings and apply across the urban-rural continuum. The substantive finding in relation to age at first presentation may indicate that a gradient of socioeconomic position is influential on delay in presentation to mental health services.

Social class at birth and risk of psychosis

BACKGROUND

Individuals with psychotic disorders are represented more in the lower social classes, yet there is conflicting evidence to whether these individuals drift into the lower social classes or whether lower social class is a risk factor for developing psychosis. The aim of this study was to examine whether the social class at birth is a risk factor for developing psychosis.

METHODS

We included individuals with a first episode of psychosis (FEP) whose social class at birth was determined from birth records. We employed a case-control study design and also compared the distribution of the social classes at birth of the cases to that of the general population.

RESULTS

A total of 380 individuals with an FEP and 760 controls were included in the case-control study. The odds ratio for developing an FEP associated with social class (low vs high) was .62 (95% confidence interval (CI): .46-.85, p < .001), indicating that individuals from a lower social class at birth have a reduced risk of psychosis. Individuals born between 1961 and 1980 with an FEP were more likely to be from a higher social class at birth compared to the general population (60.8% vs 36.7%, χ(2) = 60.85, df = 1, p < .001). However, this association was not observed for those born between 1981 and 1990.

CONCLUSION

A higher social class at birth is associated with a greater risk for developing a psychotic disorder; however, this effect may show temporal variation.

Assessment of Lifespan Functioning Attainment (ALFA) scale: A quantitative interview for self-reported current and functional decline in schizophrenia

Schizophrenia has been characterized as a disorder with poor outcomes across various functional domains, especially social and occupational functioning. Although these outcomes have been investigated based on patients' current functioning, few studies have considered the assessment of functional outcomes across the lifespan in schizophrenia. We developed a novel and brief scale of adulthood lifespan functioning, the Assessment of Lifespan Functioning Attainment (ALFA). We assessed current functioning and percentage of pre- and post-psychosis onset engagement for five functional domains including paid employment, living independently, romantic partnerships, close friendships, and recreational engagement with others. Pre-to post-psychosis functional decline was observed for all domains, with paid employment having the greatest decline (d = 2.68) and living independently having the least decline (d = .59). Our exploratory factor analysis suggests that a single factor accounted for the most variance in Pre-Psychosis Functioning in ALFA domains. Two factors explain the majority of variance in Post-Psychosis Functioning and Pre-to-Post Psychosis Decline: a sociability factor (close friendships and recreational engagement with others) and an independence factor (paid employment, living independently, romantic relationships). To our knowledge, this is the first study to report on a self-reported quantitative assessment of adult lifespan functioning in schizophrenia. The ALFA scale may be a useful tool for future research on functional outcomes in schizophrenia.

Risk of schizophrenia and minority status: a comparison of the Swedish-speaking minority and the Finnish-speaking majority in Finland

Approximately five percent of the Finnish population are Swedish-speaking and have higher socioeconomic position and longer life expectancy than the Finnish-speaking majority. Previous studies have not investigated whether Swedish-speaking Finns have lower risk of schizophrenia spectrum disorders (SSD) than Finnish-speaking Finns. We investigated this in a representative sample of 47 445 Finns born in 1972-1984. Hazard ratios of SSD between language groups were assessed with conditional proportional hazards regression. Sex, parental ages at birth, paternal employment around conception, parental psychosis and place and residence in the capital area were used as other explanatory variables. The prevalence of SSD was 0.7% in the Swedish-speaking minority and 1.5% in the Finnish-speaking majority. In the adjusted regression model, belonging to the Swedish-speaking minority was associated with lower risk of SSD (hazard ratio (HR) 0.41, 95% confidence interval (CI) 0.24-0.69). In a subset analysis by gender, the protective effect was evident among Swedish-speaking males (HR 0.32, 95% CI 0.15-0.68) but marginal in females (HR 0.75, 95% CI 0.41-1.37). Parental psychosis and place of birth in the capital area were associated with higher risk of SSD, whereas paternal employment at the time of conception was associated with lower risk of SSD. Our results support the role of social factors in the etiology of schizophrenia. Belonging to a minority with high socioeconomic status and social capital may be protective against schizophrenia, especially for males.