Brain structure correlates of urban upbringing, an environmental risk factor for schizophrenia

Whole-brain gray matter volume and fractional anisotropy of the posterior thalamic radiation and sagittal stratum in healthy adults correlate with the local environment

The impacts of air pollution, local climate, and urbanization on human health have been well-documented in recent studies. In this study, we combined magnetic resonance imaging (MRI) brain analysis with a questionnaire survey on the local environment in 141 healthy middle-aged men and women. Our findings reveal that a favorable environment is positively correlated with gray matter volume (GMV) in the frontal and occipital lobes, cerebellum, and whole brain, as well as with fractional anisotropy (FA) in the fornix (including the fornix stria terminalis), posterior thalamic radiation (PTR), sagittal stratum (SS), and whole brain. Among these, significant correlations between the local environment and whole-brain and cerebellar GMV, PTR, and SS FA remained after Bonferroni correction. Additionally, the positive relationship between the local environment and whole-brain GMV was further supported by principal component analysis (PCA). This is the first study to demonstrate that healthy adult brain structure, as indicated by GMV and FA values, can be influenced by the local environment.

Large-scale georeferenced neuroimaging and psychometry data link the urban environmental exposome with brain health

In face of cumulating evidence about the impact of human-induced environmental changes on mental health and behavior, our understanding of the main effects and interactions between environmental factors - i.e., the exposome and the brain - is still limited. We seek to fill this knowledge gap by leveraging georeferenced large-scale brain imaging and psychometry data from the adult community-dwelling population (n = 2672; mean age 63 ± 10 years). For monitoring brain anatomy, we extract morphometry features from a nested subset of the cohort (n = 944) with magnetic resonance imaging. Using an iterative analytical strategy testing the moderator role of geospatially encoded exposome factors on the association between brain anatomy and psychometry, we demonstrate that individuals' anxiety state and psychosocial functioning are among the mental health characteristics showing associations with the urban exposome. The clusters of higher anxiety state and lower current psychosocial functioning coincide spatially with a lower vegetation density and higher air pollution. The univariate multiscale geographically weighted regression identifies the spatial scale of associations between individuals' levels of anxiety state, psychosocial functioning, and overall cognition with vegetation density, air pollution and structures of the limbic network. Moreover, the multiscale geographically weighted regression interaction model reveals spatially confined exposome features with moderating effect on the brain-psychometry/cognitive performance relationships. Our original findings testing the role of exposome factors on brain and behavior at the individual level, underscore the role of environmental and spatial context in moderating brain-behavior dynamics across the adult lifespan.

Considering the interconnected nature of social identities in neuroimaging research

Considerable heterogeneity exists in the expression of complex human behaviors across the cognitive, personality and mental health domains. It is increasingly evident that individual variability in behavioral expression is substantially affected by sociodemographic factors that often interact with life experiences. Here, we formally address the urgent need to incorporate intersectional identities in neuroimaging studies of behavior, with a focus on research in mental health. We highlight how diverse sociodemographic factors influence the study of psychiatric conditions, focusing on how interactions between those factors might contribute to brain biology and illness expression, including prevalence, symptom burden, help seeking, treatment response and tolerance, and relapse and remission. We conclude with a discussion of the considerations and actionable items related to participant recruitment, data acquisition and data analysis to facilitate the inclusion and incorporation of diverse intersectional identities in neuroimaging.

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

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

Defining Urbanicity in the Context of Psychosis Research: A Qualitative Systematic Literature Review

BACKGROUND AND HYPOTHESIS

Numerous studies have found that being born or raised in urban environments increases the odds of developing psychosis in Northern and Western Europe. However, available research from Southern Europe, Latin America, and Asia has reported null results. A limitation in most studies to date is the inadequate characterization of urban and rural life components that may contribute to varying psychosis risk across regions.

STUDY DESIGN

To deepen our understanding of the different concepts and measures of urbanicity and related factors in psychosis research, we conducted a qualitative systematic literature review extracting information from studies published between 2000 and 2024.

STUDY RESULTS

Sixty-one articles met the inclusion and exclusion criteria and were used in the thematic analysis. The analysis revealed that urbanicity lacked a single, coherent definition across studies and regions. Three major categories of themes were developed from the analysis: (1) Urbanicity comprises several interconnected constructs, (2) Urbanicity measurements vary between countries from the Global North and the Global South, and (3) Urbanicity operates through key neighborhood-level mechanisms.

CONCLUSIONS

Future research on urbanicity and psychosis should consider the potential limitations of urbanicity's conceptualization and operationalization and aim to address these limitations by focusing on contextual, historical, and community-level factors, utilizing locally validated measures, and employing mixed-method designs.

How does the macroenvironment influence brain and behaviour-a review of current status and future perspectives

The environment influences brain and mental health, both detrimentally and beneficially. Existing research has emphasised the individual psychosocial 'microenvironment'. Less attention has been paid to 'macroenvironmental' challenges, including climate change, pollution, urbanicity, and socioeconomic disparity. Notably, the implications of climate and pollution on brain and mental health have only recently gained prominence. With the advent of large-scale big-data cohorts and an increasingly dense mapping of macroenvironmental parameters, we are now in a position to characterise the relation between macroenvironment, brain, and behaviour across different geographic and cultural locations globally. This review synthesises findings from recent epidemiological and neuroimaging studies, aiming to provide a comprehensive overview of the existing evidence between the macroenvironment and the structure and functions of the brain, with a particular emphasis on its implications for mental illness. We discuss putative underlying mechanisms and address the most common exposures of the macroenvironment. Finally, we identify critical areas for future research to enhance our understanding of the aetiology of mental illness and to inform effective interventions for healthier environments and mental health promotion.

Sex-dependent association study of complement C4 gene with treatment-resistant schizophrenia and hospitalization frequency

The complement component 4 (C4) gene, codes for two isotypes, C4A and C4B, and can exist in long or short forms (C4L and C4S). The C4AL variant has been associated with elevated schizophrenia (SCZ) risk. Here, we investigated the relationship between C4 variation and clinical outcomes in SCZ. N = 434 adults with SCZ or schizoaffective disorder were included in this retrospective study. A three-step genotyping workflow was performed to determine C4 copy number variants. These variants were tested for association with clinical outcome measures, including treatment-resistant SCZ (TRS), number of hospitalizations (NOH), and symptom severity (PANSS). Sex and ancestry stratified analyses were performed. We observed a marginally significant association between C4S and TRS in males only, and a negative association between C4S and NOH in the total sample. C4AS had negative association with NOH in males and non-Europeans. Lastly, C4A copy numbers and C4A predicted brain expression showed negative association with NOH in males only. Our study provides further support for sex-specific effect of C4 on SCZ clinical outcomes, and also suggests that C4S and C4AS might have a protective effect against increased severity. C4 could potentially serve as a genetic biomarker in the future, however, more research is required.

Neural Correlates of Early-Life Urbanization and Their Spatial Relationships with Gene Expression, Neurotransmitter, and Behavioral Domain Atlases

Previous neuroimaging research has established associations between urban exposure during early life and alterations in brain function and structure. However, the molecular mechanisms and behavioral relevance of these associations remain largely unknown. Here, we aimed to address this question using a combined analysis of multimodal data. Initially, we calculated amplitude of low-frequency fluctuations (ALFF) and gray matter volume (GMV) using resting-state functional and structural MRI to investigate their associations with early-life urbanization in a large sample of 511 healthy young adults. Then, we examined the spatial relationships of the identified neural correlates of early-life urbanization with gene expression, neurotransmitter, and behavioral domain atlases. Results showed that higher early-life urbanization scores were correlated with increased ALFF of the right fusiform gyrus and decreased GMV of the left dorsal medial prefrontal cortex and left precuneus. Remarkably, the identified neural correlates of early-life urbanization were spatially correlated with expression of gene categories primarily involving immune system process, signal transduction, and cellular metabolic process. Concurrently, there were significant associations between the neural correlates and specific neurotransmitter systems including dopamine, acetylcholine, and serotonin. Finally, we found that the ALFF correlates were associated with behavioral terms including "perception," "sensory," "cognitive control," and "reasoning." Apart from expanding existing knowledge of early-life urban environmental risk for mental disorders and health in general, our findings may contribute to an emerging framework for integrating social science, neuroscience, genetics, and public policy to respond to the major health challenge of world urbanization.

Exploring causal mechanisms of psychosis risk

Robust epidemiological evidence of risk and protective factors for psychosis is essential to inform preventive interventions. Previous evidence syntheses have classified these risk and protective factors according to their strength of association with psychosis. In this critical review we appraise the distinct and overlapping mechanisms of 25 key environmental risk factors for psychosis, and link these to mechanistic pathways that may contribute to neurochemical alterations hypothesised to underlie psychotic symptoms. We then discuss the implications of our findings for future research, specifically considering interactions between factors, exploring universal and subgroup-specific factors, improving understanding of temporality and risk dynamics, standardising operationalisation and measurement of risk and protective factors, and developing preventive interventions targeting risk and protective factors.

Low-Level Visual Features of Window Views Contribute to Perceived Naturalness and Mental Health Outcomes

Previous studies have shown that natural window views are beneficial for mental health, but it is still unclear which specific features constitute a 'natural' window view. On the other hand, studies on image analysis found that low-level visual features (LLVFs) are associated with perceived naturalness, but mainly conducted experiments with brief stimulus presentations. In this study, research on the effects of window views on mental health was combined with the detailed analysis of LLVFs. Healthy adults rated window views from their home and sent in photographs of those views for analysis. Content validity of the 'ecological' view assessment was evaluated by checking correlations of LLVFs with window view ratings. Afterwards, it was explored which of the LLVFs best explained variance in perceived percentage of nature and man-made elements, and in ratings of view quality. Criterion validity was tested by investigating which variables were associated with negative affect and impulsive decision-making. The objective and subjective assessments of nature/sky in the view were aligned but objective brightness was unreliable. The perceived percentage of nature was significantly explained by green pixel ratio, while view quality was associated with fractals, saturation, sky pixel ratio and straight edge density. The higher subjective brightness of rooms was associated with a lower negative affect, whereas results for impulsive decision-making were inconsistent. The research highlights the validity to apply LLVFs analysis to ecological window views. For affect, subjective brightness seemed to be more relevant than LLVFs. For impulsive decision-making, performance context needs to be controlled in future studies.

Smartphone-based ecological momentary assessment reveals an incremental association between natural diversity and mental wellbeing

Using smartphone-based ecological momentary assessment, this study investigated an association between natural diversity on mental wellbeing. A sample of 1,998 participants completed 41,448 assessments between April 2018 and September 2023. Environments which included a larger range of natural features, such as trees, plants and birdlife (high natural diversity) were associated with greater mental wellbeing than environments including a smaller range of natural features (low natural diversity). There was evidence of a mediating effect of natural diversity on the association between natural environments and mental wellbeing. These results highlight the importance of policies and practices that support richness of biodiversity for public mental health.

Childhood urbanicity is associated with emotional episodic memory-related striatal function and common variation in NTRK2

BACKGROUND

Childhoods in urban or rural environments may differentially affect the risk of neuropsychiatric disorders, possibly through memory processing and neural response to emotional stimuli. Genetic factors may not only influence individuals' choices of residence but also modulate how the living environment affects responses to episodic memory.

METHODS

We investigated the effects of childhood urbanicity on episodic memory in 410 adults (discovery sample) and 72 adults (replication sample) with comparable socioeconomic statuses in Beijing, China, distinguishing between those with rural backgrounds (resided in rural areas before age 12 and relocated to urban areas at or after age 12) and urban backgrounds (resided in cities before age 12). We examined the effect of childhood urbanicity on brain function across encoding and retrieval sessions using an fMRI episodic memory paradigm involving the processing of neutral or aversive pictures. Moreover, genetic association analyses were conducted to understand the potential genetic underpinnings that might contribute to memory processing and neural mechanisms influenced by early-life urban or rural environments.

RESULTS

Episodic memory retrieval accuracy for more difficult neutral stimuli was similar between those with urban and rural childhoods, whereas aversive stimuli elicited higher retrieval accuracy in the urban group (P = 0.023). For aversive stimuli, subjects with urban childhood had relatively decreased engagement of the striatum at encoding and decreased engagement of the hippocampus at retrieval. This more efficient striatal encoding of aversive stimuli in those with urban childhoods was associated with common variation in neurotrophic tyrosine kinase receptor type 2 (NTRK2) (right striatum: P = 1.58×10-6). These findings were confirmed in the replication sample.

CONCLUSIONS

We suggest that this differential striatal processing of aversive stimuli observed in individuals with urban or rural childhoods may represent mechanisms by which childhood urbanicity may affect brain circuits, heightening behavioral responses to negative stressors associated with urban environments. NTRK2-associated neural processes in the striatum may play a role in these processes.

Association between urban upbringing and functional brain connectivity in schizophrenia

Background

Environmental factors considerably influence the development of the human cortex during the perinatal period, early childhood, and adolescence. Urban upbringing in the first 15 years of life is a known risk factor for schizophrenia (SCZ). Though the risk of urban birth and upbringing is well-examined from an epidemiological perspective, the biological mechanisms underlying urban upbringing remain unknown. The effect of urban birth and upbringing on functional brain connectivity in SCZ patients is not yet examined.

Methods

This is a secondary data analysis of three studies that included 87 patients with SCZ and 70 healthy volunteers (HV) aged 18 to 50 years. We calculated the developmental urbanicity index using a validated method in earlier studies. Following standard pre-processing of resting functional magnetic resonance imaging (fMRI) scans, seed-return on investment (ROI) functional connectivity analysis was performed.

Results

The results showed a significant association between urban birth and upbringing on functional connectivity in SCZ patients and HV (P < 0.05). In SCZ patients, connections from the right caudate, anterior cingulate cortex, left and right intracalcarine cortices, left and right lingual gyri, left posterior parahippocampal cortex to the cerebellum, fusiform gyri, lateral occipital cortex, and amygdala were significantly associated with the urbanicity index (P < 0.05).

Conclusions

These study findings suggest a significant association between urban birth and upbringing on functional brain connectivity in regions involved in reward processing and social cognition in SCZ. Assessment of social cognition could have implications in developing an in-depth understanding of this impairment in persons with SCZ.

Exploring the enigma of low prevalence of post-traumatic stress disorder in India

Introduction

Post-traumatic stress disorder (PTSD) is a chronic psychiatric condition associated with significant distress and dysfunction. While worldwide estimates of prevalence range from 3.9% to 24%, little research has been conducted to identify the prevalence of PTSD in the general population of India. This study analyzes data from the National Mental Health Survey 2015-2016, a comprehensive epidemiological study of mental health disorders in India, to explore the unique characteristics and prevalence of PTSD in the Indian population.

Materials and Methods

The National Mental Health Survey 2015-2016 employed a multiple-stage, stratified, cluster-sampling methodology, covering 39,532 individuals in 12 states of India. The Mini-International Neuropsychiatric Interview (MINI) version 6.0.0 was used to diagnose psychiatric disorders, including PTSD. A detailed analysis of sociodemographic profiles, prevalence patterns, comorbidities, economic and social impact, and treatment-seeking behavior was conducted. Firth penalized logistic regression was employed to identify associated sociodemographic factors.

Results

The study revealed a low prevalence of PTSD in India at 0.2%, significantly lower than global averages. Factors associated with PTSD included female gender, middle age (40-49 years), and urban residence. The study also highlighted a high rate of comorbid mood and anxiety disorders, substantial disability, poor treatment-seeking behavior, and significant suicidal risk among individuals with PTSD.

Conclusion

Our findings underscore the need for culturally informed diagnostic and management programs to accurately identify and address PTSD in the Indian population. Cultural nuances, stigma, and the use of Western-derived diagnostic instruments likely contribute to the underidentification and undertreatment of PTSD in India. The study emphasizes the importance of recognizing and addressing these challenges to improve mental health outcomes in India.

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

BACKGROUND AND HYPOTHESIS

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

STUDY DESIGN

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

STUDY RESULTS

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

CONCLUSIONS

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

How does the macroenvironment influence brain and behaviour - a review of current status and future perspectives

The environment influences mental health, both detrimentally and beneficially. Current research has emphasized the individual psychosocial 'microenvironment'. Less attention has been paid to 'macro-environmental' challenges including climate change, pollution, urbanicity and socioeconomic disparity. With the advent of large-scale big-data cohorts and an increasingly dense mapping of macroenvironmental parameters, we are now in a position to characterise the relation between macroenvironment, brain, and behaviour across different geographic and cultural locations globally. This review synthesises findings from recent epidemiological and neuroimaging studies, aiming to provide a comprehensive overview of the existing evidence between the macroenvironment and the structure and functions of the brain, with a particular emphasis on its implications for mental illness. We discuss putative underlying mechanisms and address the most common exposures of the macroenvironment. Finally, we identify critical areas for future research to enhance our understanding of the aetiology of mental illness and to inform effective interventions for healthier environments and mental health promotion.

The effects of environmental factors associated with childhood urbanicity on brain structure and cognition

Urbanization is a trend lasting for more than one century worldwide. Four hundred ninety male and female adult Chinese Han participants with different urban and rural childhoods were included in this study. Early-life urban environment was found benefit for total grey matter volume (GMV), dorsolateral prefrontal cortex (DLPFC) GMV, temporal pole (TP) GMV and cognition function, and negatively correlated with medial prefrontal cortex (MPFC) GMV. Regression analysis showed that maternal education was a protective factor for total and DLPFC GMVs, while having siblings was better for MPFC GMV. Total, DLPFC and TP GMVs acts mediation effects between childhood urbanicity and different cognitive domains. These findings may suggest some pros and cons on brain structure associated with childhood urbanicity and related environmental factors.

Choice matters: Pupils' stress regulation, brain development and brain function in an outdoor education project

BACKGROUND

Education outside the classroom (EOtC) is considered beneficial to children's physical and mental health. Especially, stress resilience has been linked to nature experience.

AIMS

This study experimentally explored the effects of pupils' autonomy support (AUT) and physical activity (PA) on their biological stress responses and brain development in EOtC.

SAMPLE

The study comprised 48 fifth and sixth graders.

METHODS

The intervention consisted of one day/week taught in a forest over one school year. Structural magnetic resonance imaging (MRI) was conducted at the beginning and the end of the school year, functional MRI under a stress condition at the end. Regions of interest were amygdala, hippocampus and the anterior cingulate cortex (ACC). All other measures were obtained at the beginning, at mid-term and at the end of the school year. PA was measured using accelerometry. Cortisol levels were obtained three times during the examined school days. AUT was measured with a paper-based survey. Data were analysed using Bayesian multivariate models.

RESULTS

EOtC students exhibit more efficient regulation of biological stress-reactivity and show a reduction of cortisol over the day associated with light PA in the forest. Cortisol is further associated with amygdala activation in the stress condition. Cerebral structural change is best explained by age; however, AUT has a positive direct effect on the maturation of the ACC, which is stronger in EOtC.

CONCLUSIONS

Our results support the idea that autonomy supportive teaching fosters cerebral maturation and that EOtC can have a positive effect on biological stress regulation.

Physical activity for cognitive health promotion: An overview of the underlying neurobiological mechanisms

Physical activity is one of the modifiable factors of cognitive decline and dementia with the strongest evidence. Although many influential reviews have illustrated the neurobiological mechanisms of the cognitive benefits of physical activity, none of them have linked the neurobiological mechanisms to normal exercise physiology to help the readers gain a more advanced, comprehensive understanding of the phenomenon. In this review, we address this issue and provide a synthesis of the literature by focusing on five most studied neurobiological mechanisms. We show that the body's adaptations to enhance exercise performance also benefit the brain and contribute to improved cognition. Specifically, these adaptations include, 1), the release of growth factors that are essential for the development and growth of neurons and for neurogenesis and angiogenesis, 2), the production of lactate that provides energy to the brain and is involved in the synthesis of glutamate and the maintenance of long-term potentiation, 3), the release of anti-inflammatory cytokines that reduce neuroinflammation, 4), the increase in mitochondrial biogenesis and antioxidant enzyme activity that reduce oxidative stress, and 5), the release of neurotransmitters such as dopamine and 5-HT that regulate neurogenesis and modulate cognition. We also discussed several issues relevant for prescribing physical activity, including what intensity and mode of physical activity brings the most cognitive benefits, based on their influence on the above five neurobiological mechanisms. We hope this review helps readers gain a general understanding of the state-of-the-art knowledge on the neurobiological mechanisms of the cognitive benefits of physical activity and guide them in designing new studies to further advance the field.

Social interaction, psychotic disorders and inflammation: A triangle of interest

Social interaction difficulties are a hallmark of psychotic disorders, which in some cases can be definitely traced back to autoimmunological causes. Interestingly, systemic and intrathecal inflammation have been shown to significantly influence social processing by increasing sensitivity to threatening social stimuli, which bears some resemblance to psychosis. In this article, we review evidence for the involvement of systemic and intrathecal inflammatory processes in psychotic disorders and how this might help to explain some of the social impairments associated with this group of disorders. Vice versa, we also discuss evidence for the immunomodulatory function of social interactions and their potential role for therapeutic interventions in psychotic disorders.

Urbanicity, posttraumatic stress disorder, and effect modification by socioeconomic position: A nested case-control study of the Korean National Health Insurance Database

BACKGROUND

We aimed to estimate the association between urbanicity and the onset of posttraumatic stress disorder (PTSD) and to investigate heterogeneity therein according to age and socioeconomic position (SEP).

METHODS

We analyzed administrative data from the Korean National Health Insurance Database for patients with PTSD from 2004 to 2018 (N = 109,230) and for a 1:4 sample of age-, sex-, and enrollment year-matched controls. Information on eligibility, SEP (proxied by insurance premium), place of residence, diagnosis, and medical claims was obtained. Urbanicity of administrative districts was assessed using data from the Korean Statistical Information Service, 2005-2018. We estimated hazard ratios (HRs) from baseline and time-dependent models. Subgroup analyses and polynomial splines were used to investigate heterogeneity by age and SEP.

RESULTS

Urbanicity was associated with an increased risk of PTSD (per 10%p increase, HR = 1.056, 95% CI 1.050-1.061). A positive association was estimated among patients aged 0-29 years (HR = 1.115, CI 1.106-1.124), while negative associations were estimated among patients aged 30-64 years (HR = 0.990, CI 0.987-0.994) and 65 years or older (HR = 0.992, CI 0.979-1.014). The estimated associations with urbanicity were more prominent at the extremes of SEP, but only among younger participants.

CONCLUSION

Urban residence was associated with an increased risk of PTSD diagnosis. The estimated association was larger among younger individuals (but not among middle-aged and older individuals). Among younger individuals, the estimated association was larger at both extremes of SEP.

Urbanicity-Perspectives from Neuroscience and Public Health: A Scoping Review

Urban residency is associated with exposure to environmental factors, which can influence health in many ways. Neuroscientific research, as well as Public Health research, aim towards broadening evidence in the field of Urban Health. However, it is unclear whether the association between urban living and mental illnesses is causal rather than explainable by other selective effects. This review seeks to gather information on the current evidence regarding urban living and neurological outcomes to demonstrate how Public Health and Neuroscience could complement each other in the field of Urban Health. A scoping review was conducted in four electronic databases according to the PRISMA-statement guidelines. 25 empirical studies were included. Outcomes such as schizophrenia and psychotic disorders, social and cognitive functioning were scrutinised. Evidence was found for alteration of brain functioning and brain structure. Most studies researching cognitive functioning or cognitive decline displayed possible protective effects of urban living compared to rural living. The different study designs in Public Health and Neuroscience could profit from each other. Although the comparability of studies is limited by the inconsistent assessments of urbanity. Synergies and potentials to combine aspects of Public Health and Neuroscience in the field of Urban Health to improve population health became apparent.

The Critical Roles of Early Development, Stress, and Environment in the Course of Psychosis

Psychotic disorders are highly debilitating with poor prognoses and courses of chronic illness. In recent decades, conceptual models have shaped understanding, informed treatment, and guided research questions. However, these models have classically focused on the adolescent and early adulthood stages immediately preceding onset while conceptualizing early infancy through all of childhood as a unitary premorbid period. In addition, models have paid limited attention to differential effects of types of stress; contextual factors such as local, regional, and country-level characteristics or sociocultural contexts; and the timing of the stressor or environmental risk. This review discusses emerging research suggesting that (a) considering effects specific to neurodevelopmental stages prior to adolescence is highly informative, (b) understanding specific stressors and levels of environmental exposures (i.e., systemic or contextual features) is necessary, and (c) exploring the dynamic interplay between development, levels and types of stressors, and environments can shed new light, informing a specified neurodevelopmental and multifaceted diathesis-stress model.

A one-hour walk in nature reduces amygdala activity in women, but not in men

Urban dwellers are more likely to develop mental disorders such as mood and anxiety disorder as well as schizophrenia compared to rural dwellers. Moreover, it has been demonstrated that even short-term exposure to nature can improve mood and decrease stress, but the underlying neural mechanisms are currently under investigation. In the present intervention study we examined the effects of a one-hour walk in an urban vs. natural environment on activity in the amygdala, a brain region previously associated with stress processing. Before and after the walk 63 participants underwent an fMRI paradigm inducing social stress. Since there is a pronounced gap in the literature regarding interindividual differences in stress-related neural effects of urban and natural environments, we set out to explore sex differences. We observed that amygdala activity decreased after the walk in nature, but only in women, suggesting that women may profit more from salutogenic effects of nature. Moreover, performance on the arithmetic tasks improved in women after the walk in nature, whereas men performed better after the walk in the urban environment. To our knowledge, this is the first study to report differencial tendencies in men and women concerning the stress-related neural activity as an effect of acute exposure to urban vs. natural environments. Furthermore, our findings highlight the importance of sex differences when exploring effects of the environment on brain function and stress. Evidence for beneficial effects of nature on stress-related brain regions may inform urban design policies to focus on providing more accessible green areas in cities and this study suggests that sex differences in experiencing the environment should be taken into consideration.

Differentiating distinct and converging neural correlates of types of systemic environmental exposures

Systemic environmental disadvantage relates to a host of health and functional outcomes. Specific structural factors have seldom been linked to neural structure, however, clouding understanding of putative mechanisms. Examining relations during childhood/preadolescence, a dynamic period of neurodevelopment, could aid bridge this gap. A total of 10,213 youth were recruited from the Adolescent Brain and Cognitive Development study. Self-report and objective measures (Census and Federal bureau of investigation metrics extracted using geocoding) of environmental exposures were used, including stimulation indexing lack of safety and high attentional demands, discrepancy indexing social exclusion/lack of belonging, and deprivation indexing lack of environmental enrichment. Environmental measures were related to cortical thickness, surface area, and subcortical volume regions, controlling for other environmental exposures and accounting for other brain regions. Self-report (|β| = .04-.09) and objective (|β| = .02-.06) environmental domains related to area/thickness in overlapping (e.g., insula, caudal anterior cingulate), and unique regions (e.g., for discrepancy, rostral anterior and isthmus cingulate, implicated in socioemotional functions; for stimulation, precuneus, critical for cue reactivity and integration of environmental cues; and for deprivation, superior frontal, integral to executive functioning). For stimulation and discrepancy exposures, self-report and objective measures showed similarities in correlate regions, while deprivation exposures evidenced distinct correlates for self-report and objective measures. Results represent a necessary step toward broader work aimed at establishing mechanisms and correlates of structural disadvantage, highlighting the relevance of going beyond aggregate models by considering types of environmental factors, and the need to incorporate both subjective and objective measurements in these efforts.

Early lifetime experience of urban living predicts social attention in real world crowds

More than half of the world's population is currently living in cities, with more and more people moving to densely populated areas. The experience of growing up and living in crowded environments might influence the way we explore our social environment, mainly how we attend to others. Yet, we know little about how urbanicity affects this vital function of our social life. In two studies, we use mobile eye-tracking to measure participants' social attention, while walking through a shopping mall. Results show that social density of participants' native place impacts how frequently they look at passing strangers. People who experienced more city living from birth to early adolescence, attend more to strangers' faces than their rural counterparts. Our findings demonstrate that the early experience of urban upbringing configures social attention in adulthood. The urbanicity-related bias towards social gazing might reflect a more efficient processing of social information in urban natives.

The associations between area-level residential instability and gray matter volumes from the North American Prodrome Longitudinal Study (NAPLS) consortium

INTRODUCTION

Area-level residential instability (ARI), an index of social fragmentation, has been shown to explain the association between urbanicity and psychosis. Urban upbringing has been shown to be associated with reduced gray matter volumes (GMV)s of brain regions corresponding to the right caudal middle frontal gyrus (CMFG) and rostral anterior cingulate cortex (rACC). We hypothesize that greater ARI will be associated with reduced right CMFG and rACC GMVs.

METHODS

Data were collected at baseline as part of the North American Prodrome Longitudinal Study Phase 2. Counties where participants resided during childhood were geographically coded using the US Census to area-level factors. ARI was defined as the percentage of residents living in a different house 5 years ago. Generalized linear mixed models tested associations between ARI and GMVs.

RESULTS

This study included 29 healthy controls (HC)s and 64 clinical high risk for psychosis (CHR-P) individuals who were aged 12 to 24 years, had remained in their baseline residential area, and had magnetic resonance imaging scans. ARI was associated with reduced right CMFG (adjusted β = -0.258; 95% CI = -0.502 to -0.015) and right rACC volumes (adjusted β = -0.318; 95% CI = -0.612 to -0.023). The interaction term (ARI-by-diagnostic group) in the prediction of both brain regions was not significant, indicating that the relationships between ARI and regional brain volumes held for both CHR-P and HCs.

CONCLUSIONS

ARI may adversely impact similar brain regions as urban upbringing. Further investigation into the potential mechanisms of the relationship between ARI and neurobiology, including social stress, is needed.

Spend time outdoors for your brain - an in-depth longitudinal MRI study

OBJECTIVES

The effects of nature on physical and mental health are an emerging topic in empirical research with increasing influence on practical health recommendations. Here we set out to investigate the association between spending time outdoors and brain structural plasticity in conjunctions with self-reported affect.

METHODS

We established the Day2day study, which includes an unprecedented in-depth assessment of variability of brain structure in a serial sequence of 40-50 structural magnetic resonance imaging (MRI) acquisitions of each of six young healthy participants for 6-8 months (n = 281 MRI scans in total).

RESULTS

A whole-brain analysis revealed that time spent outdoors was positively associated with grey matter volume in the right dorsolateral prefrontal cortex and positive affect, also after controlling for physical activity, fluid intake, free time, and hours of sunshine.

CONCLUSIONS

Results indicate remarkable and potentially behaviorally relevant plasticity of cerebral structure within a short time frame driven by the daily time spent outdoors. This is compatible with anecdotal evidence of the health and mood-promoting effects of going for a walk. The study may provide the first evidence for underlying cerebral mechanisms of so-called green prescriptions with possible consequences for future interventions in mental disorders.

Global urbanicity is associated with brain and behaviour in young people

Urbanicity is a growing environmental challenge for mental health. Here, we investigate correlations of urbanicity with brain structure and function, neuropsychology and mental illness symptoms in young people from China and Europe (total n = 3,867). We developed a remote-sensing satellite measure (UrbanSat) to quantify population density at any point on Earth. UrbanSat estimates of urbanicity were correlated with brain volume, cortical surface area and brain network connectivity in the medial prefrontal cortex and cerebellum. UrbanSat was also associated with perspective-taking and depression symptoms, and this was mediated by neural variables. Urbanicity effects were greatest when urban exposure occurred in childhood for the cerebellum, and from childhood to adolescence for the prefrontal cortex. As UrbanSat can be generalized to different geographies, it may enable assessments of correlations of urbanicity with mental illness and resilience globally.

Brain structural correlates of upward social mobility in ethnic minority individuals

PURPOSE

Perigenual anterior cingulate cortex (pACC) is a neural convergence site for social stress-related risk factors for mental health, including ethnic minority status. Current social status, a strong predictor of mental and somatic health, has been related to gray matter volume in this region, but the effects of social mobility over the lifespan are unknown and may differ in minorities. Recent studies suggest a diminished health return of upward social mobility for ethnic minority individuals, potentially due to sustained stress-associated experiences and subsequent activation of the neural stress response system.

METHODS

To address this issue, we studied an ethnic minority sample with strong upward social mobility. In a cross-sectional design, we examined 64 young adult native German and 76 ethnic minority individuals with comparable sociodemographic attributes using whole-brain structural magnetic resonance imaging.

RESULTS

Results showed a significant group-dependent interaction between perceived upward social mobility and pACC gray matter volume, with a significant negative association in the ethnic minority individuals. Post-hoc analysis showed a significant mediation of the relationship between perceived upward social mobility and pACC volume by perceived chronic stress, a variable that was significantly correlated with perceived discrimination in our ethnic minority group.

CONCLUSION

Our findings extend prior work by pointing to a biological signature of the "allostatic costs" of socioeconomic attainment in socially disadvantaged upwardly mobile individuals in a key neural node implicated in the regulation of stress and negative affect.

Adolescent Brain Cognitive Development (ABCD) study Linked External Data (LED): Protocol and practices for geocoding and assignment of environmental data

Our brain is constantly shaped by our immediate environments, and while some effects are transient, some have long-term consequences. Therefore, it is critical to identify which environmental risks have evident and long-term impact on brain development. To expand our understanding of the environmental context of each child, the Adolescent Brain Cognitive Development (ABCD) Study® incorporates the use of geospatial location data to capture a range of individual, neighborhood, and state level data based on the child's residential location in order to elucidate the physical environmental contexts in which today's youth are growing up. We review the major considerations and types of geocoded information incorporated by the Linked External Data Environmental (LED) workgroup to expand on the built and natural environmental constructs in the existing and future ABCD Study data releases. Understanding the environmental context of each youth furthers the consortium's mission to understand factors that may influence individual differences in brain development, providing the opportunity to inform public policy and health organization guidelines for child and adolescent health.

How does the 'environment' come to the person? The 'ecology of the person' and addiction

Currently, psychiatry lacks a field that can be called "theoretical psychiatry", which uses theoretical concepts and explanatory models: The main stream of research is to collect data of all kinds in the hope that the computational Big Data approach will shed a bright light on the black box of mental disorders. Accordingly, the biology-based Research Domain Criteria of the National Institute of Mental Health have been established. However, as philosophical analyses of concepts and methods have shown, several epistemological gaps stand in the way of a consistent multilevel understanding of mental disorders. Also, the implicit ontological problems in the biological reduction of the psychosocial level and in the integration of so-called hard and soft disciplines are mostly left out. As a consequence, a non-reductive psychological theory of mental disorders is sought that also integrates correlating biological and sociological issues. In this context, one example of promising nonreductive psychiatric research is the option of systems/network psychopathology. The possibilities for integrating different psychological perspectives are highlighted for the field of addiction research and treatment, where pragmatic behaviorist approaches dominate over the theory-based practice of psychoanalysis. In comparing the theoretical constructs of these two approaches, the relevance of the concept of "(social) environment" as the wealth of influential sociocultural factors is discussed at levels superior to the interpersonal micro-level, namely the organizational meso- and societal macro level, which is not sufficiently considered in current biopsychiatry. On this basis of argumentation, the usefulness of grounding and framing psychiatry through the field of ecological sciences, especially human ecology, is demonstrated. Finally, to this end, an outline of an ecological model of mental health and illness is presented.

Childhood urbanicity interacts with polygenic risk for depression to affect stress-related medial prefrontal function

Urbanization is increasing globally, and is associated with stress and increased mental health risks, including for depression. However, it remains unclear, especially at the level of brain function, how urbanicity, social threat stressors, and psychiatric risk may be linked. Here, we aim to define the structural and functional MRI neural correlates of social stress, childhood urbanicity, and their putative mechanistic relevance to depressive illness risk, in terms of behavioral traits and genetics. We studied a sample of healthy adults with divergent urban and rural childhoods. We examined childhood urbanicity effects on brain structure as suggested by MRI, and its functional relevance to depression risk, through interactions between urbanicity and trait anxiety-depression, as well as between urbanicity and polygenic risk for depression, during stress-related medial prefrontal cortex (mPFC) engagement. Subjects with divergent rural and urban childhoods were similar in adult socioeconomic status and were genetically homogeneous. Urban childhood was associated with relatively reduced mPFC gray matter volumes as suggested by MRI. MPFC engagement under social status threat correlated with the higher trait anxiety-depression in subjects with urban childhoods, but not in their rural counterparts, implicating an exaggerated physiological response to the threat context with urbanicity, in association with behavioral risk for depression. Stress-associated mPFC engagement also interacted with polygenic risk for depression, significantly predicting a differential mPFC response in individuals with urban but not rural childhoods. Developmental urbanicity, therefore, appears to interact with genetic and behavioral risk for depression on the mPFC neural response to a threat context.

Association between Urban Upbringing and Compulsive Internet Use in Japan: A Cross-Sectional, Multilevel Study with Retrospective Recall

The purpose of this study was to show the association between urban upbringing and compulsive internet use (CIU). The interview data of the sample (N = 2431) was obtained from the World Mental Health Japan Second Survey and a multilevel model was used to investigate the association. Multiple imputation was also conducted in this study. Growing up in a large city was significantly associated with higher Compulsive Internet Use Scale (CIUS) scores (γ = 1.65, Standard Error (SE) = 0.45) and Mild CIU + Severe CIU (Exp(γ) = 1.44; 95% Confidence Interval (CI) (1.04-2.00)) compared to growing up in a small municipality after adjusting for both sociodemographic characteristics and psychopathology. This study showed a possible association between urban upbringing and CIU. Future studies with longitudinal design are needed to better understand this association.

Individuals at increased risk for development of bipolar disorder display structural alterations similar to people with manifest disease

In psychiatry, there has been a growing focus on identifying at-risk populations. For schizophrenia, these efforts have led to the development of early recognition and intervention measures. Despite a similar disease burden, the populations at risk of bipolar disorder have not been sufficiently characterized. Within the BipoLife consortium, we used magnetic resonance imaging (MRI) data from a multicenter study to assess structural gray matter alterations in N = 263 help-seeking individuals from seven study sites. We defined the risk using the EPIbipolar assessment tool as no-risk, low-risk, and high-risk and used a region-of-interest approach (ROI) based on the results of two large-scale multicenter studies of bipolar disorder by the ENIGMA working group. We detected significant differences in the thickness of the left pars opercularis (Cohen's d = 0.47, p = 0.024) between groups. The cortex was significantly thinner in high-risk individuals compared to those in the no-risk group (p = 0.011). We detected no differences in the hippocampal volume. Exploratory analyses revealed no significant differences in other cortical or subcortical regions. The thinner cortex in help-seeking individuals at risk of bipolar disorder is in line with previous findings in patients with the established disorder and corresponds to the region of the highest effect size in the ENIGMA study of cortical alterations. Structural alterations in prefrontal cortex might be a trait marker of bipolar risk. This is the largest structural MRI study of help-seeking individuals at increased risk of bipolar disorder.

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.

DNA Methylation and Resting Brain Function Mediate the Association between Childhood Urbanicity and Better Speed of Processing

Urbanicity has been suggested to affect cognition, but the underlying mechanism remains unknown. We examined whether epigenetic modification (DNA methylation, DNAm), and brain white matter fiber integrity (fractional anisotropy, FA) or local spontaneous brain function activity (regional homogeneity, ReHo) play roles in the association between childhood urbanicity and cognition based on 497 healthy Chinese adults. We found significant correlation between childhood urbanicity and better cognitive performance. Multiset canonical correlation analysis (mCCA) identified an intercorrelated DNAm-FA-ReHo triplet, which showed significant pairwise correlations (DNAm-FA: Bonferroni-adjusted P, Pbon = 4.99E-03, rho = 0.216; DNAm-ReHo: Pbon = 4.08E-03, rho = 0.239; ReHo-FA: Pbon = 1.68E-06, rho = 0.328). Causal mediation analysis revealed that 1) ReHo mediated 10.86% childhood urbanicity effects on the speed of processing and 2) childhood urbanicity alters ReHo through DNA methylation in the cadherin and Wnt signaling pathways (mediated effect: 48.55%). The mediation effect of increased ReHo in the superior temporal gyrus underlying urbanicity impact on a better speed of processing was further validated in an independent cohort. Our work suggests a mediation role for ReHo, particularly increased brain activity in the superior temporal gyrus, in the urbanicity-associated speed of processing.

Stability of hippocampal subfield volumes after trauma and relationship to development of PTSD symptoms

BACKGROUND

The hippocampus plays a central role in post-traumatic stress disorder (PTSD) pathogenesis, and the majority of neuroimaging research on PTSD has studied the hippocampus in its entirety. Although extensive literature demonstrates changes in hippocampal volume are associated with PTSD, fewer studies have probed the relationship between symptoms and the hippocampus' functionally and structurally distinct subfields. We utilized data from a longitudinal study examining post-trauma outcomes to determine whether hippocampal subfield volumes change post-trauma and whether specific subfields are significantly associated with, or prospectively related to, PTSD symptom severity. As a secondary aim, we leveraged our unique study design sample to also investigate reliability of hippocampal subfield volumes using both cross-sectional and longitudinal pipelines available in FreeSurfer v6.0.

METHODS

Two-hundred and fifteen traumatically injured individuals were recruited from an urban Emergency Department. Two-weeks post-injury, participants underwent two consecutive days of neuroimaging (time 1: T1, and time 2: T2) with magnetic resonance imaging (MRI) and completed self-report assessments. Six-months later (time 3: T3), participants underwent an additional scan and were administered a structured interview assessing PTSD symptoms. First, we calculated reliability of hippocampal measurements at T1 and T2 (automatically segmented with FreeSurfer v6.0). We then examined the prospective (T1 subfields) and cross-sectional (T3 subfields) relationship between volumes and PTSD. Finally, we tested whether change in subfield volumes between T1 and T3 explained PTSD symptom variability.

RESULTS

After controlling for sex, age, and total brain volume, none of the subfield volumes (T1) were prospectively related to T3 PTSD symptoms nor were subfield volumes (T3) associated with current PTSD symptoms (T3). Tl - T2 reliability of all hippocampal subfields ranged from good to excellent (intraclass correlation coefficient (ICC) values > 0.83), with poorer reliability in the hippocampal fissure.

CONCLUSION

Our study was a novel examination of the prospective relationship between hippocampal subfield volumes in relation to PTSD in a large trauma-exposed urban sample. There was no significant relationship between subfield volumes and PTSD symptoms, however, we confirmed FreeSurfer v6.0 hippocampal subfield segmentation is reliable when applied to a traumatically-injured sample, using both cross-sectional and longitudinal analysis pipelines. Although hippocampal subfield volumes may be an important marker of individual variability in PTSD, findings are likely conditional on the timing of the measurements (e.g. acute or chronic post-trauma periods) and analysis strategy (e.g. cross-sectional or prospective).

The role of the gut microbiome in the development of schizophrenia

Schizophrenia is a heterogeneous neurodevelopmental disorder involving the convergence of a complex and dynamic bidirectional interaction of genetic expression and the accumulation of prenatal and postnatal environmental risk factors. The development of the neural circuitry underlying social, cognitive and emotional domains requires precise regulation from molecular signalling pathways, especially during critical periods or "windows", when the brain is particularly sensitive to the influence of environmental input signalling. Many of the brain regions involved, and the molecular substrates sub-serving these domains are responsive to life-long microbiota-gut-brain (MGB) axis signalling. This intricate microbial signalling system communicates with the brain via the vagus nerve, immune system, enteric nervous system, enteroendocrine signalling and production of microbial metabolites, such as short-chain fatty acids. Preclinical data has demonstrated that MGB axis signalling influences neurotransmission, neurogenesis, myelination, dendrite formation and blood brain barrier development, and modulates cognitive function and behaviour patterns, such as, social interaction, stress management and locomotor activity. Furthermore, preliminary clinical studies suggest altered gut microbiota profiles in schizophrenia. Unravelling MGB axis signalling in the context of an evolving dimensional framework in schizophrenia may provide a more complete understanding of the neurobiological architecture of this complex condition and offers the possibility of translational interventions.

Ambulatory assessment for precision psychiatry: Foundations, current developments and future avenues

Precision psychiatry stands to benefit from the latest digital technologies for assessment and analyses to tailor treatment towards individuals. Insights into dynamic psychological processes as they unfold in humans' everyday life can critically add value in understanding symptomatology and environmental stressors to provide individualized treatment where and when needed. Towards this goal, ambulatory assessment encompasses methodological approaches to investigate behavioral, physiological, and biological processes in humans' everyday life. It combines repeated assessments of symptomatology over time, e.g., via Ecological Momentary Assessment (e.g., smartphone-diaries), with monitoring of physical behavior, environmental characteristics (such as geolocations, social interactions) and physiological function via sensors, e.g., mobile accelerometers, global-positioning-systems, and electrocardiography. In this review, we expand on promises of ambulatory assessment in the investigation of mental states (e.g., real-life, dynamical and contextual perspective), on chances for precision psychiatry such as the prediction of courses of psychiatric disorders, detection of tipping points and critical windows of relapse, and treatment effects as exemplified by ongoing projects, and on future avenues of how ambulatory interventions can benefit personalized care for psychiatric patients (e.g., through real-time feedback in everyday life). Ambulatory assessment is a key contributor to precision psychiatry, opening up promising avenues in research, diagnoses, prevention and treatment.

Investigating the mental health implications of urban environments with neuroscientific methods and mobile technologies: A systematic literature review

Urbanization is an ongoing global process that is influencing and shaping individual mental health and well-being. This paper aims to provide an overview of the current literature containing state-of-the-art neuroscientific and mobile technologies that have been used to investigate the mental health implications of urban environments. Searches for peer-reviewed primary research articles were conducted in PubMed and SCOPUS, returning 33,443 papers; 90 empirical articles published from 1981 to 2021 were included in the final synthesis. Central findings suggest virtual reality and mobile electroencephalography to be the most commonly used methods, and demanding mood, affect, and health phenomena or states to be the most common concepts of study in both physical built settings and natural urban spaces. Recommendations for both future practice and study noting particular opportunities for future methodological contributions are discussed.

Urban upbringing and psychiatric disorders in the United States: A racial comparison

BACKGROUND

Studies that link urbanicity to mental health are mixed depending on outcome and context. More research is needed to examine whether the urban upbringing effect holds true across racial populations in a large and diverse country like the United States.

METHODS

We analyzed two large datasets that were administered contemporaneously with similar methods: The National Comorbidity Survey-Replication (NCS-R, Whites) and the National Survey of American Life (NSAL, Blacks). We ran multivariable logistic regression models to examine the associations between area of upbringing (urban/large city, other, rural) and six psychiatric disorders, controlling for sex, age, years of education and income-to-poverty ratio (and ethnicity in the NSAL). We performed these analyses in both the NCS-R and the NSAL separately.

RESULTS

The majority (58.97%) of the White sample grew up in the 'other' category (i.e. small town, small city, or suburb of a large city), whereas a much larger percentage (39.89%) of the Black sample grew up in a large city. In the White sample, urban upbringing was not associated with any of the psychiatric disorders at a conventional level of statistical significance. In the Black sample, urban upbringing was associated with greater odds of having mood disorder, alcohol use disorder and drug use disorder, but was not significantly associated with anxiety disorders, PTSD, or eating disorders.

CONCLUSIONS

Urban upbringing was not associated with psychiatric disorders among Whites, but was associated with greater odds of mood disorders, alcohol us disorder and drug use disorder among Blacks. Future research can elucidate how differences in urban upbringing between Whites and Blacks are linked to differences in risk for psychiatric disorders.

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.

[IMAGEN and beyond: novel population neuroscientific strategies for clinical and global cohorts in the STRATIFY and GIGA consortia]

Cohort studies provide the possibility to more precisely define treatment and preventive approaches to mental diseases, when genetic and personal influences as well as sociocultural and environmental factors and their interactions are taken into account. This article presents cohort research approaches, which are dedicated to this aim and reports the lessons learnt and achievements made in the IMAGEN cohort study and the resulting further developments. Specifically, we focus on novel assessment instruments, the implementation of larger clinical and geographic ranges and innovative forms of data analysis.

Brain functional connectivity differs when viewing pictures from natural and built environments using fMRI resting state analysis

Human beings evolved in “natural” environments. Many intervention studies have shown that exposure to natural environments (compared to built/urban environments) reduces stress and increases cognitive functioning. We set out to test differences in fMRI functional connectivity while showing participants photographs from natural versus built environments (matched in terms of scenicness ratings). No differences in self-reported perceived stress, rumination, valence, arousal or dominance were observed. However, functional connectivity was significantly higher when participants saw natural rather than built environmental photographs in circuits consisting of dorsal attention network (DAN) and ventral attention network (VAN), DAN and default mode network (DMN) and DMN and Somatomotor connections. In addition, we observed lower functional connectivity during the natural environment condition correlated with more years that individuals spent in major cities during upbringing. Future studies, linking changes in cognitive functioning due to nature exposure and alterations in functional connectivity, are warranted.

How Do Urban Environments Affect Young People's Mental Health? A Novel Conceptual Framework to Bridge Public Health, Planning, and Neurourbanism

Childhood and adolescence are crucial periods for mental and social development. Currently, mental illness among young people is a global epidemic, and rates of disorders such as depression and anxiety are rising. Urban living, compared with rural living, is linked with a higher risk of serious mental illness, which is important because the world is urbanizing faster than ever before. Urban environments and their landscapes, designs, and features influence mental health and well-being. However, no conceptual frameworks to date have detailed the effect of urban environments on young people's mental health, and few studies have considered the growing role of digital and social media in this relationship, leading to calls for the development of holistic approaches to describe this relationship. This article synthesizes existing knowledge on urban places (both built and natural environments) and mental health in the public health and urban planning literature and examines the emerging field of neurourbanism (a multidisciplinary study of the effect of urban environments on mental health and brain activity) to enhance current practice and research. We developed 2 novel conceptual frameworks (1 research-oriented, 1 practice-oriented), adapted from Bronfenbrenner's socioecological model, that focus on the relationship between urban environments and young people's mental health. We added a digital and social media contextual level to the socioecological model, and we applied a multilayer concept to highlight potential cross-field interactions and collaborations. The proposed frameworks can help to guide future practice and research in this area.

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

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

Urban upbringing and psychotic experiences in the United States: A racial and geographic comparison

Urban upbringing has been associated with greater risk for psychotic experiences, though research is needed to confirm whether this is true in the U.S., and whether the association depends on race, type of experience, and region of the country. We analyzed data from the National Comorbidity Survey Replication (White respondents only) and the National Survey of American Life (Black respondents). Multivariable logistic regression models found that urban upbringing was not significantly associated with lifetime psychotic experiences for Whites, but was significantly associated with lower odds for Blacks, adjusting for socio-demographic covariates and common mental disorders. Rural upbringing was associated with greater odds of lifetime auditory hallucinatory experiences for Blacks. Exploratory analyses suggested growing up in a large city or 'other' environment were associated with greater odds of lifetime psychotic experiences among Whites currently residing in the Northeast, but lower odds among Whites residing in the South. For Blacks currently residing in the West, rural upbringing was associated with significantly greater odds of lifetime psychotic experiences when compared with growing up in a large city. White and Blacks may have different lived experiences in urban and rural settings, calling for more race- and location- specific research to explain these diverging patterns.