Social Stress and Psychosis Risk: Common Neurochemical Substrates?

The mental and physical health correlates of psychotic experiences among US college students: Findings from the Healthy Mind Study 2020

BACKGROUND

Psychotic experiences have been framed as a marker of mental and physical health status; however, more research is needed to confirm these associations in university populations.

METHODS

We analyzed data from the Healthy Minds Survey (Fall Semester Cohort 2020), which is a non-probability sample of students attending one of 28 universities in the United States, who completed an online survey (September 2020-December 2020). We used multivariable logistic regression to examine the associations between several mental and physical health conditions and psychotic experiences, adjusting for age, gender, sexual orientation race/ethnicity, and international student status.

RESULTS

In terms of mental health, all conditions were associated with greater odds of having lifetime psychotic experiences. Having at least one mental health condition was associated with 2.18 times greater odds of having lifetime psychotic experiences (aOR: 2.18; 95% CI: 1.96-2.42). In terms of physical health, having at least one physical health condition was associated with 1.37 times greater odds of having lifetime psychotic experiences (aOR: 1.37; 95% CI: 1.22-1.53), but only four conditions were associated with greater odds of lifetime psychotic experiences, which were: asthma, gastrointestinal disease, HIV/AIDS, and other chronic disease. The counts of mental and physical health conditions were associated with greater odds of lifetime psychotic experiences in a dose-dependent fashion.

CONCLUSION

Psychotic experiences appear to be an indicator for mental health problems and some physical health problems. More research is needed to determine whether assessing for psychotic experiences broadly can help identify at-risk individuals in university settings who may benefit from targeted preventive interventions.

Chronic social stress in early life can predispose mice to antisocial maltreating behavior

Purpose

In our previous study, we developed an assay system to evaluate antisocial maltreating behavior of conspecific mice using a perpetrator-victim paradigm. We also generated a mouse model for the maltreating behavior by mimicking child maltreatment or abuse. Here, we further investigate the antisocial behavior using anti-aggressive and antipsychotic drugs.

Methods

Model mice sequentially subjected to maternal separation (MS), social defeat (SD), and social isolation (SI) in that order (MS/SD/SI model) were subjected to a maltreating behavioral task. The MS/SD/SI mice were treated with oxytocin (OXY), clozapine (CLZ), haloperidol (HAL), and 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT). Western blotting and enzyme-linked immunosorbent assay were used for protein analysis.

Results

A substantial portion of the MS/SD/SI model mice (46% of males and 40% of females) showed a higher number of nose pokes than the control. OXY or 8-OH-DPAT treatment reduced the high number of nose pokes by the MS/SD/SI mice, whereas HAL increased it. CLZ did not affect the number of nose pokes by the MS/SD/SI mice. Interestingly, although the OXY level in the MS/SD/SI mice was similar to that in the control, the amount of OXY receptor was lower in the MS/SD/SI mice. The amount of 5-HT1A receptor was also decreased in the MS/SD/SI mice.

Conclusion

Chronic social stress in childhood might predispose a mouse to antisocial behavior. Our maltreating behavior assay system, including the MS/SD/SI model, is a good animal system for research on and drug screening for brain disorders associated with antisocial or psychotic behavior.

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 Translational Future of Stress Neurobiology and Psychosis Vulnerability: A Review of the Evidence

Psychosocial stress is a well-established risk factor for psychosis, yet the neurobiological mechanisms underlying this relationship have yet to be fully elucidated. Much of the research in this field has investigated hypothalamic-pituitary-adrenal (HPA) axis function and immuno-inflammatory processes among individuals with established psychotic disorders. However, as such studies are limited in their ability to provide knowledge that can be used to develop preventative interventions, it is important to shift the focus to individuals with increased vulnerability for psychosis (i.e., high-risk groups). In the present article, we provide an overview of the current methods for identifying individuals at high-risk for psychosis and review the psychosocial stressors that have been most consistently associated with psychosis risk. We then describe a network of interacting physiological systems that are hypothesised to mediate the relationship between psychosocial stress and the manifestation of psychotic illness and critically review evidence that abnormalities within these systems characterise highrisk populations. We found that studies of high-risk groups have yielded highly variable findings, likely due to (i) the heterogeneity both within and across high-risk samples, (ii) the diversity of psychosocial stressors implicated in psychosis, and (iii) that most studies examine single markers of isolated neurobiological systems. We propose that to move the field forward, we require well-designed, largescale translational studies that integrate multi-domain, putative stress-related biomarkers to determine their prognostic value in high-risk samples. We advocate that such investigations are highly warranted, given that psychosocial stress is undoubtedly a relevant risk factor for psychotic disorders.

Stress-mediated dysregulation of the Rap1 small GTPase impairs hippocampal structure and function

The effects of repeated stress on cognitive impairment are thought to be mediated, at least in part, by reductions in the stability of dendritic spines in brain regions critical for proper learning and memory, including the hippocampus. Small GTPases are particularly potent regulators of dendritic spine formation, stability, and morphology in hippocampal neurons. Through the use of small GTPase protein profiling in mice, we identify increased levels of synaptic Rap1 in the hippocampal CA3 region in response to escalating, intermittent stress. We then demonstrate that increased Rap1 in the CA3 is sufficient in and of itself to produce stress-relevant dendritic spine and cognitive phenotypes. Further, using super-resolution imaging, we investigate how the pattern of Rap1 trafficking to synapses likely underlies its effects on the stability of select dendritic spine subtypes. These findings illuminate the involvement of aberrant Rap1 regulation in the hippocampus in contributing to the psychobiological effects of stress.

Connecting Neurobiological Features with Interregional Dysconnectivity in Social-Cognitive Impairments of Schizophrenia

Schizophrenia (SZ) is a devastating psychiatric disorder affecting about 1% of the world's population. Social-cognitive impairments in SZ prevent positive social interactions and lead to progressive social withdrawal. The neurobiological underpinnings of social-cognitive symptoms remain poorly understood, which hinders the development of novel treatments. At the whole-brain level, an abnormal activation of social brain regions and interregional dysconnectivity within social-cognitive brain networks have been identified as major contributors to these symptoms. At the cellular and subcellular levels, an interplay between oxidative stress, neuroinflammation and N-methyl-D-aspartate receptor hypofunction is thought to underly SZ pathology. However, it is not clear how these molecular processes are linked with interregional dysconnectivity in the genesis of social-cognitive symptoms. Here, we aim to bridge the gap between macroscale (connectivity analyses) and microscale (molecular and cellular mechanistic) knowledge by proposing impaired myelination and the disinhibition of local microcircuits as possible causative biological pathways leading to dysconnectivity and abnormal activity of the social brain. Furthermore, we recommend electroencephalography as a promising translational technique that can foster pre-clinical drug development and discuss attractive drug targets for the treatment of social-cognitive symptoms in SZ.

The association between psychosocial stress, interpersonal sensitivity, social withdrawal and psychosis relapse: a systematic review

Psychosis is associated with a high risk of relapse, with 67% of clients relapsing within one year following a first episode. In light of the high personal, social, and healthcare costs of the illness, it is paramount to understand the risk factors associated with psychosis relapse. The current systematic review aims to critically review the role of psychosocial stress in psychosis relapse in individuals with an established psychotic disorder. This review systematically searched Ovid (PsycINFO, EMBASE, MEDLINE) literature databases from inception until 28th February 2022. Sixteen studies were eligible for inclusion. Most studies found that individuals with psychosis demonstrate high levels of psychosocial stress and are more likely to be socially withdrawn compared to healthy controls or other clinical presentations. Most studies reported a statistically significant association between psychosocial stress and psychosis relapse, as well as between social withdrawal and psychosis relapse. However, no studies examined the association between high levels of interpersonal sensitivity and psychosis relapse. Individuals with psychosis tend to experience high levels of psychosocial stress and social withdrawal, and these appear to increase the risk of psychosis relapse. Due to high levels of heterogeneity within the literature, we could only conduct a narrative synthesis of the findings. Future studies would benefit from employing a meta-analytic approach.

COVID-19 and New-Onset Psychosis: A Comprehensive Review

Psychosis is a multifactorial condition that typically involves delusions, hallucinations, and disorganized thought, speech or behavior. The observation of an association between infectious epidemics and acute psychosis dates back to the last century. Recently, concerns have been expressed regarding COVID-19 and the risk for the development of new-onset psychosis. This article reviewed the current evidence of a possible link between SARS-CoV-2 and risk of psychosis as an acute or post-infectious manifestation of COVID-19. We here discuss potential neurobiological and environmental factors as well as a number of challenges in ascribing a causal pathogenic relationship between SARS-CoV-2 infection and new-onset psychosis.

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.

Stress symptoms and associated factors among adolescents in Dhaka, Bangladesh: findings from a cross-sectional study

BACKGROUND

Stress affects adolescents' daily lives by disrupting their working capacity and begets comorbidity. This study aimed to estimate the prevalence of stress symptoms and the factors associated with these symptoms among secondary school-going adolescents in Bangladesh.

METHODS

A cross-sectional study using two-stage cluster sampling was conducted. A self-administered questionnaire was given to 2355 adolescents from nine secondary schools in Dhaka, Bangladesh. Of the respondents, 2313 completed the 10-item Perceived Stress Scale (PSS-10). Sociodemographic information, self-reported body image, a modified Leisure Time Exercise Questionnaire (LTEQ), and the WHO Global Physical Activity Questionnaire (GPAQ) were used to determine the sociodemographic and lifestyle factors associated with stress symptoms among adolescents.

RESULTS

Findings suggest that about 65% of adolescents experienced moderate stress symptoms, and about 9% experienced high-stress symptoms. Females (58.7%) suffered more from stress compared to males (41.3%). Age, grade, and residential setting were significantly associated with stress. Logistic regression estimates show that level of physical activity (AOR: 1.52; 95% CI:1.26-1.84), sleep dissatisfaction (AOR: 1.33; 95% CI: 1.07-1.65), and perception of self as overweight/obese (AOR: 1.46; 95% CI: 1.13-1.89) were significantly associated with stress symptoms among adolescents.

CONCLUSIONS

Stress symptoms are highly prevalent among secondary school adolescents in Bangladesh. Further exploratory investigations are needed on possible intervention strategies to reduce the burden of stress among adolescents.

Glial receptor PLXNB2 regulates schizophrenia-related stress perception via the amygdala

Stress is a trigger for the development of psychiatric disorders. However, how stress trait differs in schizophrenia patients is still unclear. Stress also induces and exacerbates immune activation in psychiatric disorders. Plexins (Plxn) and its ligands semaphorins (Sema) are important cellular receptors with plural functions in both the brain and the immune system. Recently, the role of Plxn/Sema in regulation of neuroinflammation was also noticed. Here, when investigating immune mechanisms underlying stress susceptibility in schizophrenia, we discovered the role of Plxnb2 in stress response. Patients of first-episode schizophrenia (FES) with high stress (FES-hs, n=51) and low stress (FES-ls, n=50) perception and healthy controls (HCs) (n=49) were first recruited for neuroimaging and blood bulk RNA sequencing (RNA-seq). A mouse model of chronic unpredictable stress (CUS) and intra-amygdaloid functional blocking of Plxnb2 were further explored to depict target gene functions. Compared to HCs, FES-hs patients had bigger caudate and thalamus (FDR=0.02&0.001, respectively) whereas FES-ls patients had smaller amygdala (FDR=0.002). Blood RNA-seq showed differentially expressed PLXNB2 and its ligands among patient groups and HCs (FDR<0.05~0.01). Amygdaloid size and PLXNB2 level were both negatively correlated with stress perception (p<0.01&0.05, respectively), which fully mediated the amygdaloid positive association with PLXNB2 expression (β=0.9318, 95% CI: 0.058~1.886) in FES-hs patients. In mice, Plxnb2 was enriched in astrocytes and microglia and CUS reduced its expression in astrocytes (p<0.05). Inhibition of amygdaloid Plxnb2 by its functional blocking monoclonal antibody (mAb)-102 induced mice anxiety (p<0.05), amygdaloid enlargement (p<0.05), and microglial ramification (p<0.001) compared to saline. These data suggest that PLXNB2 regulates amygdala-dependent stress responses.

Chronic social stress during early development is involved in antisocial maltreatment behavior in mice

Purpose

Early-life stress can cause brain inflammation and affect social behavior in adulthood. In humans, maltreated (abused or neglected) children often exhibit antisocial behavior, including violent and sadistic behavior, in adulthood. However, it is unknown whether maltreatment behavior occurs in rodents. Here, we developed an assay system to evaluate conspecific maltreatment behavior in the mouse.

Methods

To assess maltreatment behavior, we devised a two-chamber apparatus separated by a transparent partition, in which one chamber was provided with a nose-poking hole that would trigger foot shocks onto the other. Lidocaine was used to inhibit neural activity in vivo. Brain oscillations were investigated by electroencephalograph. Enzyme-linked immunosorbent assay was used for protein assay. The mouse model was sequentially subjected to maternal separation (MS), social defeat (SD), and social isolation (SI) in that order (MS/SD/SI model).

Results

Inactivation of the anterior cingulate cortex and medial prefrontal cortex increased the level of nose-poking. Maltreatment behavior provoked changes in oxytocin, corticosterone, and brain-derived neurotrophic factor levels. MS/SD/SI mice exhibited more sustained nose-poking behavior during the experiment, resulting in increased foot shocks to the mouse in the opposite chamber. Abnormal brain oscillations were observed in the MS/SD/SI mice.

Conclusion

The MS/SD/SI model and maltreatment-behavior assay may be useful not only to study the relationship between social stress in childhood and antisocial behavior in adulthood, but also for study of etiology, pathology, or treatment for brain disorders, such as psychopathy.

Linking Salience Signaling With Early Adversity and Affective Distress in Individuals at Clinical High Risk for Psychosis: Results From an Event-Related fMRI Study

Evidence suggests dysregulation of the salience network in individuals with psychosis, but few studies have examined the intersection of stress exposure and affective distress with prediction error (PE) signals among youth at clinical high-risk (CHR). Here, 26 individuals at CHR and 19 healthy volunteers (HVs) completed a monetary incentive delay task in conjunction with fMRI. We compared these groups on the amplitudes of neural responses to surprising outcomes-PEs without respect to their valence-across the whole brain and in two regions of interest, the anterior insula and amygdala. We then examined relations of these signals to the severity of depression, anxiety, and trauma histories in the CHR group. Relative to HV, youth at CHR presented with aberrant PE-evoked activation of the temporoparietal junction and weaker deactivation of the precentral gyrus, posterior insula, and associative striatum. No between-group differences were observed in the amygdala or anterior insula. Among youth at CHR, greater trauma histories were correlated with stronger PE-evoked amygdala activation. No associations were found between affective symptoms and the neural responses to PE. Our results suggest that unvalenced PE signals may provide unique information about the neurobiology of CHR syndromes and that early adversity exposure may contribute to neurobiological heterogeneity in this group. Longitudinal studies of young people with a range of risk syndromes are needed to further disentangle the contributions of distinct aspects of salience signaling to the development of psychopathology.

Altered relationship between cortisol response to social stress and mediotemporal function during fear processing in people at clinical high risk for psychosis: a preliminary report

Evidence suggests that people at Clinical High Risk for Psychosis (CHR) have a blunted cortisol response to stress and altered mediotemporal activation during fear processing, which may be neuroendocrine-neuronal signatures of maladaptive threat responses. However, whether these facets are associated with each other and how this relationship is affected by cannabidiol treatment is unknown. We examined the relationship between cortisol response to social stress and mediotemporal function during fear processing in healthy people and in CHR patients. In exploratory analyses, we investigated whether treatment with cannabidiol in CHR individuals could normalise any putative alterations in cortisol-mediotemporal coupling. 33 CHR patients were randomised to 600 mg cannabidiol or placebo treatment. Healthy controls (n = 19) did not receive any drug. Mediotemporal function was assessed using a fearful face-processing functional magnetic resonance imaging paradigm. Serum cortisol and anxiety were measured immediately following the Trier Social Stress Test. The relationship between cortisol and mediotemporal blood-oxygen-level-dependent haemodynamic response was investigated using linear regression. In healthy controls, there was a significant negative relationship between cortisol and parahippocampal activation (p = 0.023), such that the higher the cortisol levels induced by social stress, the lower the parahippocampal activation (greater deactivation) during fear processing. This relationship differed significantly between the control and placebo groups (p = 0.033), but not between the placebo and cannabidiol groups (p = 0.67). Our preliminary findings suggest that the parahippocampal response to fear processing may be associated with the neuroendocrine (cortisol) response to experimentally induced social stress, and that this relationship may be altered in patients at clinical high risk for psychosis.

Heightened risk factors in the midst of the pandemic: Supporting individuals with psychosis during COVID-19

PURPOSE

This article aims to describe distinct vulnerabilities to the psychosocial stress from coronavirus disease 2019 (COVID-19) on individuals with psychosis and provide practical ways to reduce the vulnerabilities.

CONCLUSION

Societal changes and stress have come in the wake of the COVID-19. Individuals with psychosis are more susceptible to stress, cognitive biases, and lack social support. Practitioners working with individuals with psychosis are in a unique position to offer ways to reduce risk.

PRACTICE IMPLICATIONS

Care during the pandemic requires practitioners to pay particular attention to magnified risk factors to individuals with psychosis and create a plan to offer adjunct support.

Current psychosocial stress, childhood trauma and cognition in patients with schizophrenia and healthy participants

BACKGROUND

Cognitive difficulties are experienced frequently in schizophrenia (SZ) and are strongly predictive of functional outcome. Although severity of cognitive difficulties has been robustly associated with early life adversity, whether and how they are affected by current stress is unknown. The present study investigated whether acute stress reactivity as measured by heart rate and mood changes predict cognitive performance in patients with schizophrenia and healthy individuals, and whether this is moderated by diagnosis and previous childhood trauma exposure.

METHODS

One hundred and four patients with schizophrenia and 207 healthy participants were administered a battery of tasks assessing cognitive performance after psychosocial stress induction (Trier Social Stress Test; TSST). Mood states (Profile of Mood States; POMS) and heart rate were assessed at baseline, immediately before, and after the TSST.

RESULTS

Both healthy participants and patients showed increases in POMS Tension and Total Mood Disturbance scores between Time Point 2 (pre-TSST) and Time Point 3 (post-TSST). These changes were not associated with variation in cognition. Although childhood trauma exposure was associated with higher stress reactivity and poorer cognitive function in all participants, childhood trauma did not moderate the association between stress reactivity and cognition. Neither was diagnosis a moderator of this relationship.

DISCUSSION

These findings suggest that while chronic stress exposure explains significant variation in cognition, acute stress reactivity (measured by changes in Tension and Total Mood Disturbance) did not. In the context of broader developmental processes, we conclude that stressful events that occur earlier in development, and with greater chronicity, are likely to be more strongly associated with cognitive variation than acute transient stressors experienced in adulthood.

Sexual minority status, social adversity and risk for psychotic disorders-results from the GROUP study

BACKGROUND

Lesbian, bisexual, or gay individuals (LBGs) have an increased risk for mental health problems compared to heterosexuals, but this association has sparsely been investigated for psychotic disorders. The aim of this study was: (1) to examine whether LBG sexual orientation is more prevalent in individuals with a non-affective psychotic disorder (NAPD) than in people without a psychotic disorder; and if so, (2) to explore possible mediating pathways.

METHODS

Sexual orientation was assessed in the 6-year follow-up assessment of the Dutch Genetic Risk and Outcome of Psychosis study (GROUP), a case-control study with 1547 participants (582 patients with psychotic disorder, 604 siblings, and 361 controls). Binary logistic regression analyses were used to calculate the risk of patients with a psychotic disorder being LBG, compared to siblings and controls. Perceived discrimination, history of bullying, childhood trauma (CT), and sexual identity disclosure were investigated as potential mediating variables.

RESULTS

The proportion of individuals with LBG orientation was 6.8% in patients (n = 40), 4.3% in siblings (n = 26), and 2.5% in controls (n = 10). The age- and gender-adjusted odds ratio of LBG for patients was 1.57 (95% CI 1.08-2.27; p = 0.019), compared to siblings and controls. Discrimination, bullying, and CT all partially mediated this association.

CONCLUSIONS

Adverse social experiences related to sexual minority status may increase the risk for NAPD. Sexual identity, behavior, and difficulties need more attention in everyday clinical practice.

Impact of the first Covid-19 pandemic wave on first episode psychosis in Milan, italy

The ongoing Corona Virus Disease 2019 (COVID-19) pandemic appears to increase risk for mental illness, either directly due to inflammation caused by the virus or indirectly due to related psychosocial stress, resulting in the development of both anxious-depressive and psychotic symptoms. The purpose of the present study was to assess the frequency and characteristics of all patients with First Episodes Psychosis (FEP) without COVID-19 infection hospitalized in the first four months since lockdown in Milan. We recruited sixty-two patients hospitalized between March 8 to July 8, 2020 versus those first  hospitalized in the same period in 2019. The two subgroups were compared for sociodemographic variables and clinical characteristics of the episodes. Patients with FEP in 2020 were significantly older than patients with FEP in 2021, and presented with significantly less substances abuse. Interestingly, patients presenting with FEP in 2020 were significantly older than patients with FEP in 2019. These data are compatible with the greater vulnerability to stressful factors during the pandemic, as well as with the greater concern regarding a possible COVID-19 infection producing brain damage causing the FEP.

Relation between self-perceived stress, psychopathological symptoms and the stress hormone prolactin in emerging psychosis

BACKGROUND

Psychosocial stress and the stress hormone prolactin are assumed to play an important role in the pathogenesis of schizophrenia and related psychoses, and have been frequently observed to be increased in antipsychotic-naïve patients with a clinical high risk for psychosis (CHR-P) or first episode of psychosis (FEP). The aim of this study was to further elucidate the relationships between self-perceived stress, psychopathological symptoms and prolactin levels in these patients.

METHODS

In this cross-sectional study, 45 healthy controls, 31 CHR-P patients and 87 FEP patients were recruited from two different study centers. Prolactin was measured under standardized conditions between 8 and 10 am. All patients were antipsychotic-naïve and not taking any prolactin influencing medication. Self-perceived stress during the last month was measured with the perceived stress scale (PSS-10) immediately before blood taking.

RESULTS

Both CHR-P and FEP patients showed significantly higher levels of self-perceived stress and prolactin than controls. Hyperprolactinemia (i.e. prolactin levels above the reference range) was observed in 26% of CHR-P and 45% of FEP patients. Self-perceived stress was significantly positively associated with affective symptoms, but not with other symptoms. There was no significant association between self-perceived stress and prolactin levels.

CONCLUSION

Our results confirm that CHR-P and FEP patients have higher stress levels than healthy controls and frequently have hyperprolactinemia, independent of antipsychotic medication. However, although it is well established that prolactin increases in response to stress, our results do not support the notion that increased prolactin levels in these patients are due to stress.

Perceived stress influences anhedonia and social functioning in a community sample enriched for psychosis-risk

Existing animal and human research support the causal role of stress in the emergence of anhedonia, and in turn, the influence of anhedonia in social functioning. However, this model has not been tested in relation to psychosis-risk; this literature gap is notable given that both anhedonia and declining social functioning represent key markers of risk of developing a psychotic disorder such as schizophrenia. The current research tested the evidence for this model using structural equation modeling in 240 individuals selected based on a range of psychosis-risk symptomatology from the general community. Results supported this model in comparison with alternative models, and additionally emphasized the direct role of perceived stress in social functioning outcomes. Findings suggest the clinical relevance of targeting early perceptions of stress in individuals meeting psychosis-risk self-report criteria in an effort to prevent subsequent anhedonia and declines in social functioning.

Endocannabinoid system in trauma and psychosis: distant guardian of mental stability

Central endocannabinoid system (eCBS) is a neuromodulatory system that inhibits potentially harmful, excessive synaptic activation. Endocannabinoid receptors are abundant among brain structures pivotal in different mental disorders development (for example, hippocampus, amygdala, medial-prefrontal cortex, hypothalamus). Here, we review eCBS function in etiology of psychosis, emphasizing its role in dealing with environmental pressures such as traumatic life events. Moreover, we explore eCBS as a guard against hypothalamic-pituitary-adrenal axis over-activation, and discuss its possible role in etiology of different psychopathologies. Additionally, we review eCBS function in creating adaptive behavioral patterns, as we explore its involvement in the memory formation process, extinction learning and emotional response. We discuss eCBS in the context of possible biomarkers of trauma, and in preclinical psychiatric conditions, such as at-risk mental states and clinical high risk states for psychosis. Finally, we describe the role of eCBS in the cannabinoid self-medication-theory and extinction learning.

Psychopathology in refugees subjected to the Dublin Regulation: an Italian study

BACKGROUND

Literature shows that migrants-a generic definition for persons who leave their own country of origin-have increased psychopathological vulnerability. Between 2014 and 2017, 976 963 non-European Union (non-EU) people arrived in Italy, of which 30% for humanitarian reasons. This study is aimed at a better understanding of the experience of asylum seekers who transferred to Italy were subjected to the EU Dublin Regulation and most of them suspended in their asylum application.

METHODS

We elaborate a descriptive study based on a population of refugees and asylum seekers who have suffered from social and personal migratory stressful factors. Clinical data was collected between 2011 and 2013 at the "A. Gemelli" General Hospital IRCCS, Rome, Italy. Minors, elderly people, and patients who are unable to declare a voluntary consensus and economic migrants were excluded from the study. Candidates for the status of refugee or asylum seekers were included.

RESULTS

The sample consisted of 180 asylum seekers aged 25.52 ± 5.6 years. Most frequently diagnosis was post-traumatic stress disorder (PTSD) (53%), subthreshold PTSD was reported in 22% of subjects. We found phenomenological patterns highly representative of PTSD of the dissociative subtype. Around 20% of the sample suffered from psychotic symptomatology.

CONCLUSIONS

Loss of the migratory project and the alienation mediated by chronic social defeat paradigm may trigger a psychopathological condition described by the failure to cope with the negative emotional context of social exclusion and solitude. A common and integrated treatment project is needed, with the scope of reintegrating the migrant's personal and narrative identity.

Striatal dopamine synthesis capacity in autism spectrum disorder and its relation with social defeat: an [18F]-FDOPA PET/CT study

Alterations in dopamine signalling have been implied in autism spectrum disorder (ASD), and these could be associated with the risk of developing a psychotic disorder in ASD adults. Negative social experiences and feelings of social defeat might result in an increase in dopamine functioning. However, few studies examined dopamine functioning in vivo in ASD. Here we examine whether striatal dopamine synthesis capacity is increased in ASD and associated with social defeat. Forty-four unmedicated, non-psychotic adults diagnosed with ASD and 22 matched controls, aged 18-30 years, completed a dynamic 3,4-dihydroxy-6-[¹⁸F]-fluoro-L-phenylalanine positron emission tomography/computed tomography ([¹⁸F]-FDOPA PET/CT) scan to measure presynaptic dopamine synthesis capacity in the striatum. We considered unwanted loneliness, ascertained using the UCLA Loneliness Scale, as primary measure of social defeat. We found no statistically significant difference in striatal dopamine synthesis capacity between ASD and controls (F_1,60 = 0.026, p = 0.87). In ASD, striatal dopamine synthesis capacity was not significantly associated with loneliness (β = 0.01, p = 0.96). Secondary analyses showed comparable results when examining the associative, limbic, and sensorimotor sub-regions of the striatum (all p-values > 0.05). Results were similar before and after adjusting for age, sex, smoking-status, and PET/CT-scanner-type. In conclusion, in unmedicated, non-psychotic adults with ASD, striatal dopamine synthesis capacity is not increased and not associated with social defeat.

[Social defeat and schizophrenia: Hypotheses, arguments, mechanisms]

There is growing evidence for a main role of environment in the occurrence of mental disorders such as a psychosocial risk factor, for example, childhood trauma, discrimination linked to minority status, or migrant status. One hypothesis is that social adversity factors influence the risk of schizophrenia through a common pathway: social defeat which could be defined as the impotence of a subject in the face of a situation of social adversity, with a consequential experience of devaluation on the social scale. This review proposes to explain the animal model of social defeat which provides an overview of the neurobiological consequences of chronic stress. Then, we expose this topic in humans, the assessment methods, and its psychopathological field. Finally, we expose epidemiologic and neurobiological evidences, in particular the dopaminergic sensitization process, which provide evidence of a significant role of social defeat in schizophrenia risk due to exposure to psychosocial factors. This etiopathogenic hypothesis has several issues. First, a common pathway to several environmental risk factors could allow an ethiopathogenic model more parcimonious for schizophrenia. It could also allow the assessment and prevention of adversity factors involved in social defeat so as to finally improve the outcome of subjects who have an individual risk for schizophrenia.

The gut microbiome and antipsychotic treatment response

Patients with psychosis usually respond to one antipsychotic drug and not to another; one third fail to respond to any. Some patients, who initially do well, stop responding. Some develop serious side effects even at low doses. While several of the reasons for this variability are known, many are not. The aim of this review is to explore the potential role of intestinal organisms in response/non-response to antipsychotics. Much of the literature in this field is relatively new and still, for the most part, theoretical. A growing number of animal experiments and clinical trials are starting to point, however, to substantial effects of antipsychotics on the composition of gut bacteria and, reciprocally, to the effects of microbiota on the pharmacokinetics of antipsychotic medication. Because so many factors influence the constituents of the human intestine, it is difficult, at present, to sort out how much one or more either enhance or dampen the benefits of antipsychotics or the character/severity of the adverse effects they induce. Dietary and other therapies are being devised to reverse dysbiosis. If successful, such therapies plus the modification of factors that, together, are known to determine the composition of microbiota could help to maximize the effectiveness of currently available antipsychotic therapy.

Hypothalamic-pituitary-adrenal axis function and exposure to stress factors and cannabis use in recent-onset psychosis

Objectives: Previous studies suggest that childhood trauma, stressful life events, and cannabis use are associated with psychosis. We aimed to explore whether these environmental factors have an effect on hypothalamic-pituitary-adrenal (HPA) axis indices in recent-onset psychosis.Methods: We studied 56 recent-onset psychosis outpatients and 47 healthy controls. Childhood trauma was assessed with the Childhood Trauma Questionnaire. Stressful life events were assessed with the Holmes-Rahe Social Readjustment Scale. Cannabis use was assessed by semistructured interviews. Several HPA axis measures were analysed in saliva: cortisol awakening response (CAR), diurnal cortisol slope, and dexamethasone suppression test ratio (DSTR) after 0.25 mg of dexamethasone. Multiple linear regression analyses were conducted to explore the contribution of environmental factors to each HPA axis measure while adjusting for covariates (diagnosis, age, gender, smoking, body mass index and treatments).Results: There were no significant differences in HPA axis measures between diagnostic groups. Cannabis use was associated with a more flattened diurnal cortisol slope (standardized β = 0.21, p = 0.038), independent of recent-onset psychosis diagnosis. No associations were found between environmental factors and other HPA axis measures (CAR, DSTR).Conclusions: Our study provides evidence for the effect of cannabis exposure in cortisol secretion patterns in both healthy controls and recent-onset psychosis patients.

Childhood trauma and being at-risk for psychosis are associated with higher peripheral endocannabinoids

BACKGROUND

Evidence has been accumulating regarding alterations in components of the endocannabinoid system in patients with psychosis. Of all the putative risk factors associated with psychosis, being at clinical high-risk for psychosis (CHR) has the strongest association with the onset of psychosis, and exposure to childhood trauma has been linked to an increased risk of development of psychotic disorder. We aimed to investigate whether being at-risk for psychosis and exposure to childhood trauma were associated with altered endocannabinoid levels.

METHOD

We compared 33 CHR participants with 58 healthy controls (HC) and collected information about previous exposure to childhood trauma as well as plasma samples to analyse endocannabinoid levels.

RESULTS

Individuals with both CHR and experience of childhood trauma had higher N-palmitoylethanolamine (p < 0.001) and anandamide (p < 0.001) levels in peripheral blood compared to HC and those with no childhood trauma. There was also a significant correlation between N-palmitoylethanolamine levels and symptoms as well as childhood trauma.

CONCLUSIONS

Our results suggest an association between CHR and/or childhood maltreatment and elevated endocannabinoid levels in peripheral blood, with a greater alteration in those with both CHR status and history of childhood maltreatment compared to those with either of those risks alone. Furthermore, endocannabinoid levels increased linearly with the number of risk factors and elevated endocannabinoid levels correlated with the severity of CHR symptoms and extent of childhood maltreatment. Further studies in larger cohorts, employing longitudinal designs are needed to confirm these findings and delineate the precise role of endocannabinoid alterations in the pathophysiology of psychosis.

Urbanicity: The need for new avenues to explore the link between urban living and psychosis

AIM

A growing body of evidence suggests that urban living contributes to the development of psychosis. However, the mechanisms underlying this phenomenon remain unclear. This paper aims to explore the best available knowledge on the matter, identify research gaps and outline future prospects for research strategies.

METHOD

A comprehensive literature survey on the main computerized medical research databases, with a time limit up to August 2017 on the issue of urbanicity and psychosis has been conducted.

RESULTS

The impact of urbanicity may result from a wide range of factors (from urban material features to stressful impact of social life) leading to "urban stress." The latter may link urban upbringing to the development of psychosis through overlapping neuro- and socio-developmental pathways, possibly unified by dopaminergic hyperactivity in mesocorticolimbic system. However, "urban stress" is poorly defined and research based on patients' experience of the urban environment is scarce.

CONCLUSIONS

Despite accumulated data, the majority of studies conducted so far failed to explain how specific factors of urban environment combine in patients' daily life to create protective or disruptive milieus. This undermines the translation of a vast epidemiological knowledge into effective therapeutic and urbanistic developments. New studies on urbanicity should therefore be more interdisciplinary, bridging knowledge from different disciplines (psychiatry, epidemiology, human geography, urbanism, etc.) in order to enrich research methods, ensure the development of effective treatment and preventive strategies as well as create urban environments that will contribute to mental well-being.

Assessment of coexisting psychosis and substance misuse: complexities, challenges and causality

Substance misuse worsens the prognosis for people suffering psychosis and places them at risk of being denied appropriate mental health service interventions. To increase the chances of its success, the plan of management for patients with coexisting psychosis and substance misuse should be based on a valid formulation of their problems, which in turn is dependent on the clinician having (a) a thorough understanding of the bidirectional and changing ways that substance use and mental illness symptoms can interact, (b) an awareness of their own biased implicit assumptions about causality in explaining these interactions and (c) a framework for assessment and formulation. This article addresses these three areas with reference to the evidence base and to clinical experience in a way that guides mental health clinicians in the assessment of patients with coexisting psychosis and substance misuse.

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

IMPORTANCE

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

OBJECTIVE

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

DESIGN, SETTING, AND PARTICIPANTS

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

EXPOSURES

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

MAIN OUTCOMES AND MEASURES

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

RESULTS

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

CONCLUSIONS AND RELEVANCE

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

Urbanicity, biological stress system functioning and mental health in adolescents

Growing up in an urban area has been associated with an increased chance of mental health problems in adults, but less is known about this association in adolescents. We examined whether current urbanicity was associated with mental health problems directly and indirectly via biological stress system functioning. Participants (n = 323) were adolescents from the Dutch general population. Measures included home and laboratory assessments of autonomic nervous system and hypothalamic-pituitary-adrenal axis functioning, neighborhood-level urbanicity and socioeconomic status, and mother- and adolescent self-reported mental health problems. Structural equation models showed that urbanicity was not associated with mental health problems directly. Urbanicity was associated with acute autonomic nervous system and hypothalamic-pituitary-adrenal axis reactivity such that adolescents who lived in more urban areas showed blunted biological stress reactivity. Furthermore, there was some evidence for an indirect effect of urbanicity on mother-reported behavioral problems via acute autonomic nervous system reactivity. Urbanicity was not associated with overall autonomic nervous system and hypothalamic-pituitary-adrenal axis reactivity or basal hypothalamic-pituitary-adrenal axis functioning. Although we observed some evidence for associations between urbanicity, biological stress reactivity and mental health problems, most of the tested associations were not statistically significant. Measures of long-term biological stress system functioning may be more relevant to the study of broader environmental factors such as urbanicity.

Urbanicity, hypothalamic-pituitary-adrenal axis functioning, and behavioral and emotional problems in children: a path analysis

BACKGROUND

Urbanization is steadily increasing worldwide. Previous research indicated a higher incidence of mental health problems in more urban areas, however, very little is known regarding potential mechanisms underlying this association. We examined whether urbanicity was associated with mental health problems in children directly, and indirectly via hypothalamic-pituitary-adrenal (HPA)-axis functioning.

METHODS

Utilizing data from two independent samples of children we examined the effects of current urbanicity (n = 306, ages seven to 12 years) and early childhood urbanicity (n = 141, followed from birth through age 7 years). Children's mothers reported on their mental health problems and their family's socioeconomic status. Salivary cortisol samples were collected during a psychosocial stress procedure to assess HPA axis reactivity to stress, and at home to assess basal HPA axis functioning. Neighborhood-level urbanicity and socioeconomic conditions were extracted from Statistics Netherlands. Path models were estimated using a bootstrapping procedure to detect indirect effects.

RESULTS

We found no evidence for a direct effect of urbanicity on mental health problems, nor were there indirect effects of urbanicity through HPA axis functioning. Furthermore, we did not find evidence for an effect of urbanicity on HPA axis functioning or effects of HPA axis functioning on mental health problems.

CONCLUSIONS

Possibly, the effects of urbanicity on HPA axis functioning and mental health do not manifest until adolescence. An alternative explanation is a buffering effect of high family socioeconomic status as the majority of children were from families with an average or high socioeconomic status. Further studies remain necessary to conclude that urbanicity does not affect children's mental health via HPA axis functioning.

The Prodrome of Psychotic Disorders: Identification, Prediction, and Preventive Treatment

Twenty-five years ago "at risk" for psychosis criteria were introduced to the field. Prediction studies have identified a range of risk factors involved in transition from "at risk" status to first episode psychotic illness, with recent interest in dynamic and multimodal prediction models. Treatment studies have indicated that risk of transition to psychotic disorder can at least be delayed in this clinical population. Although the strongest evidence to date is for cognitive behavioral therapy, the optimal type and sequence of treatment remains an active area of research.

Stress and cognitive biases in schizotypy: A two-site study of bias against disconfirmatory evidence and jumping to conclusions

The dysfunctional cognitive and reasoning biases which underpin psychotic symptoms are likely to present prior to the onset of a diagnosable disorder and should therefore be detectable along the psychosis continuum in individuals with schizotypal traits. Two reasoning biases, Bias Against Disconfirmatory Evidence (BADE) and Jumping to Conclusions (JTC), describe how information is selected and weighed under conditions of uncertainty during decision making. It is likely that states such as elevated stress exacerbates JTC and BADE in individuals with high schizotypal traits vulnerable to displaying these information gathering styles. Therefore, we evaluated whether stress and schizotypy interacted to predict these reasoning biases using separate samples from the US (JTC) and England (BADE). Generally speaking, schizotypal traits and stress were not independently associated with dysfunctional reasoning biases. However, across both studies, the interaction between schizotypy traits and stress significantly predicted reasoning biases such that increased stress was associated with increased reasoning biases, but only for individuals low in schizotypal traits. These patterns were observed for positive schizotypal traits (in both samples), for negative traits (in the England sample only), but not for disorganization traits. For both samples, our findings suggest that the presence of states such as stress is associated with, though not necessarily dysfunctional, reasoning biases in individuals with low schizotypy. These reasoning biases seemed, in some ways, relatively immutable to stress in individuals endorsing high levels of positive schizotypal traits.

The importance of loneliness in psychotic-like symptoms: Data from three studies

Poor social connection or loneliness is a prominent feature of schizotypy and may exacerbate psychosis risk. Previous studies have examined the inter-relationships between loneliness and psychosis risk, but critically, they have largely been conducted in non-clinical samples or exclusively used laboratory questionnaires with limited consideration of the heterogeneity within schizotypy (i.e., positive, negative, disorganized factors). The present study examined links between loneliness and psychotic-like symptoms across the dimensions of schizotypy through cross-sectional, laboratory-based questionnaires (Study 1; N = 160), ambulatory assessment (Study 2; N = 118) in undergraduates, and ambulatory assessment in inpatients in a substance abuse treatment program (Study 3; N = 48). Trait positive schizotypy consistently predicted cross-sectional and state psychotic-like symptoms. Loneliness, assessed via cross-sectional and ambulatory means, was largely linked with psychotic-like symptoms. Importantly, psychotic-like symptoms were dynamic: psychotic-like symptoms largely increased with loneliness in individuals with elevated positive and disorganized schizotypal traits, though there were some inconsistency related to disorganized schizotypy and state psychotic-like symptoms. Negative schizotypy and loneliness did not significantly interact to predict psychotic-like symptoms, suggesting specificity to positive schizotypy. Ambulatory approaches provide the opportunity for ecologically valid identification of risk states across psychopathology, thus informing early intervention.

Psychotropic medication effects on cortisol: Implications for research and mechanisms of drug action

Stress and the hypothalamic-pituitary-adrenal (HPA) axis have been implicated in the etiology of a range psychiatric disorders; abnormalities in cortisol secretion are well documented in mood, anxiety, and psychotic disorders. There is, however, evidence that psychotropic medications affect HPA function, and are often a confound in research on the relation of cortisol secretion with psychiatric symptoms and syndromes. Psychotropic effects are particularly problematic in longitudinal research on individuals at clinical high risk (CHR) for serious mental illness, because they have the potential to obscure neurobiological mechanisms involved in crossing the threshold from CHR states to clinical disorders. This paper reviews the research literature on the relation of cortisol secretion with the three major classes of psychotropic medication that are most often prescribed; antipsychotics, antidepressants, and stimulants. The studies included in this review are those that measured both baseline and post-treatment cortisol. Taken together, most studies of antidepressants find that they are associated with a reduction in both basal and post-dexamethasone-CRH (DEX/CRH) cortisol, although some report no change. Similarly, antipsychotics, both typical and atypical, are found to reduce basal and DEX/CRH cortisol levels in most studies. Psychostimulant medications, in contrast, are associated with an increase in basal cortisol levels or no change. Effects of psychotropics on the cortisol awakening response (CAR) are less consistent. Implications of these effects for clinical research, especially studies of CHR populations, are discussed. Limitations of the research, due to variations in sample demographic and methodologic factors, are noted, and directions for future research are proposed.

Preliminary data indicating a connection between stress-induced prefrontal dopamine release and hippocampal TSPO expression in the psychosis spectrum

Prolonged stress can cause neuronal loss in the hippocampus resulting in disinhibition of glutamatergic neurons proposed to enhance dopaminergic firing in subcortical regions including striatal areas. Supporting this, imaging studies show increased striatal dopamine release in response to psychosocial stress in healthy individuals with low childhood maternal care, individuals at clinical high risk for psychosis (CHR) and patients with schizophrenia. The prefrontal cortex (PFC) is connected to the hippocampus and a key region to control neurochemical responses to stressful stimuli. We recently reported a disrupted PFC dopamine-stress regulation in schizophrenia, which was intact in CHR. Given the available evidence on the link between psychosocial stress, PFC dopamine release and hippocampal immune activation in psychosis, we explored, for the first time in vivo, whether stress-induced PFC dopamine release is associated with hippocampal TSPO expression (a neuroimmune marker) in the psychosis spectrum. We used an overlapping sample of antipsychotic-naïve subjects with CHR (n = 6) and antipsychotic-free schizophrenia patients (n = 9) from our previously published studies, measuring PFC dopamine release induced by a psychosocial stress task with [¹¹C]FLB457 positron emission tomography (PET) and TSPO expression with [¹⁸F]FEPPA PET. We observed that participants on the psychosis spectrum with lower stress-induced dopamine release in PFC had significantly higher TSPO expression in hippocampus (β = -2.39, SE = 0.96, F(1,11) = 6.17, p = 0.030). Additionally, we report a positive association between stress-induced PFC dopamine release, controlled for hippocampal TSPO expression, and Global Assessment of Functioning. This is the first exploration of the relationship between PFC dopamine release and hippocampal TSPO expression in vivo in humans.

The Fragile Brain: Stress Vulnerability, Negative Affect and GABAergic Neurocircuits in Psychosis

Persons with schizophrenia exhibit sensitivity to stress and negative affect (NA), both strongly correlated with poor functional outcome. This theoretical review suggests that NA reflects a "fragile brain," ie, vulnerable to stress, including events not experienced as stressful by healthy individuals. Based on postmortem evidence of altered gamma-aminobutyric acid (GABA) function in parvalbumin positive interneurons (PVI), animal models of PVI abnormalities and neuroimaging data with GABAergic challenge, it is suggested that GABAergic disruptions weaken cortical regions, which leads to stress vulnerability and excessive NA. Neurocircuits that respond to stressful and salient environmental stimuli, such as the hypothalamic-pituitary-adrenal axis and the amygdala, are highly dysregulated in schizophrenia, exhibiting hypo- and hyper-activity. PVI abnormalities in lateral prefrontal cortex and hippocampus have been hypothesized to affect cognitive function and positive symptoms, respectively; in the medial frontal cortex (dorsal anterior cingulate cortex and dorsal medial prefrontal cortex), these abnormalities may lead to vulnerability to stress, NA and dysregulation of stress responsive systems. Given that postmortem PVI disruptions have been identified in other conditions, such as bipolar disorder and autism, stress vulnerability may reflect a transdiagnostic dimension of psychopathology.

Acute transient psychotic disorder precipitated by Brexit vote

A man in his 40s was brought to the accident and emergency department in an acute psychotic state, 3 weeks after the European Union referendum results in the UK were declared. His mental health had deteriorated rapidly following the announcement of the results, with significant concerns about Brexit. He presented as agitated, confused and thought disordered. He had auditory hallucinations, and paranoid, referential, misidentification and bizarre delusions. He recovered completely within 2 weeks after a brief admission and treatment with olanzapine. He had experienced a similar episode of much less severity 13 years previously after major work related stress which resolved completely within a few days. He was experiencing stress related to work and family prior to the current episode which could potentially have been a contributory factor. Political events can act as major psychological stressors and have a significant impact on the mental health of people, especially those with a predisposition to develop mental illness.

Prefrontal cortical dopamine release in clinical high risk for psychosis during a cognitive task: a [11C]FLB457 positron emission tomography study

Research suggests decreased cortical dopamine is a neural correlate of cognitive deficits in schizophrenia. Evidence of impaired cognitive task-induced cortical dopamine release was demonstrated in patients with psychosis. However, whether cortical dopamine release in response to a cognitive task in clinical high risk for psychosis (CHR) is also impaired, is currently unknown. We aimed to test dopamine release in the dorsolateral prefrontal cortex (DLPFC) and the anterior cingulate cortex (ACC) in antipsychotic-free CHR participants and healthy controls (HC) performing the Wisconsin Card Sorting Task (WCST). Two [¹¹C]FLB457 PET scans were conducted for 13 CHR and 15 HC while performing the WCST and the sensorimotor control task (SMCT), respectively. A magnetic resonance image was acquired for anatomical delineation. Percentage change in binding potential (ΔBP_ND) in ACC and DLPFC in WCST were compared with the SMCT between CHR and HC. Mixed model analysis revealed no statistically significant differences in the cognitive task induced ΔBP_ND in any ROIs. There were no main effect of group (F(1, 26) = 0.348; p = 0.560) or ROI (F(1, 26) = 1.080; p = 0.308) and no significant Group x ROI interaction (F(1, 26) = 0.049; p = 0.826). Our findings suggest no statistically significant difference between CHR and HC in cognitive task-induced cortical dopamine release. This is the first in vivo study to illustrate that the cortical hypodopaminergic state observed in schizophrenia may not be present in its putative high-risk state.

Rural birth/upbringing and childhood adversities are associated with psychotic experiences in university students in China

BACKGROUND

Urbanicity has been reported to associate with an increased risk of psychotic experiences (PEs) in developed countries but less is known about the situation in developing countries. The present study aimed to investigate the effects of birth/upbringing place and other environmental factors on PEs in Chinese university students.

METHODS

A computer-assisted cross-sectional survey was conducted on 4620 second-year undergraduates, using a stratified cluster sampling. Birth places and residential mobility before 16 years old were recorded. PEs were measured using the subscales of psychoticism and paranoid ideation in the Symptom Checklist-90-R (SCL-90-R). Six questions extracted from the childhood section of the World Mental Health Composite International Diagnostic Interview (WMH-CIDI) were used to assess childhood trauma.

RESULTS

Generalized ordered logit model of multiple regression analysis revealed that participants with rural birth/upbringing (e.g. rural upbringing, on graded factor score of psychoticism and paranoid ideation [GFSPPI], 0 versus 1 & 2, odds ratio [OR] 1.409, 95% CI 1.219-1.628, p < 0.00001; 0 & 1 versus 2, OR 1.584, 95% CI 1.179-2.128, p < 0.00001) and those who reported childhood trauma (e.g. on GFSPPI, 0 versus 1 & 2, OR 1.737, 95% CI 1.498-2.014, p < 0.00001; 0 & 1 versus 2, OR 1.618, 95% CI 1.224-2.140, p < 0.00001) were apt to present more severe PEs. While upbringing places and childhood trauma affected both the presence and the severity of PEs, gender affected the presence or absence of PEs only (e.g. females, on GFSPPI, 0 versus 1 & 2, OR 1.887, 95% CI 1.631-2.183, p < 0.00001; 0 & 1 versus 2, OR 0.927, 95% CI 0.702-1.223, p = 0.593). Besides, the number of risk factors was associated with the severity of PEs in the cumulative odds logistic regression analysis (e.g. 3 risk factors versus 0 risk factor, on GFSPPI, OR 4.126, 95% CI 3.075-5.537, p < 0.00001).

CONCLUSIONS

Female, rural birth/upbringing and childhood trauma are risk factors of PEs in university students in China. The discrepancy in the findings between developed countries and China has important implications for urbanicity as a risk factor for PEs.

The role of substance use and adult sexual assault severity in the course of schizophrenia: An epidemiological catchment study of sexual assault victims

BACKGROUND

Childhood trauma increases the risk of schizophrenia, yet the role of adult sexual assault in the course of schizophrenia is unknown. This study aims to examine the associations between substance use and sexual assault severity characteristics with the course of schizophrenia among adult sexual assault victims using an epidemiologic study design.

METHODS

Sexual assault data on all individuals received from 2000 to 2010 (N = 2147) at the Center for Care of Sexual Assault Victims at Wolfson Medical Center, the largest medical center for sexual assault victims in the country, were merged with the Israel National Psychiatric Case Registry, that consisted of lifetime psychiatric hospitalizations of schizophrenia (birth to 6 years post-assault). The associations between substance use and adult sexual assault severity characteristics with hospitalizations were quantified using recurrent events Cox modeling.

RESULTS

Schizophrenia with sexual assault survivors occurred in 117 persons. Cox modeling showed that recurrent psychiatric hospitalizations were associated with younger age, sexual assault at older age, previous diagnosis of psychosis, and drug use shortly before or during the assault. Other assault characteristics (number of assailants, means of subdual, penetration type, perpetrator violence, physical injury of the victim) and immediacy of seeking help had a null association with the course of psychiatric hospitalization. These results replicated in two sensitivity analyses.

CONCLUSIONS

Substance use among victims of sexual assault was associated with an exacerbated course of schizophrenia, pointing to a possibly modifiable risk factor that should be targeted in prevention, assessment, treatment formulation and implementation.

Predictors of Transition to Psychosis in Individuals at Clinical High Risk

PURPOSE OF REVIEW

Current research is examining predictors of the transition to psychosis in youth who are at clinical high risk based on attenuated psychotic symptoms (APS). Determining predictors of the development of psychosis is important for an improved understanding of mechanisms as well as the development of preventative strategies. The purpose is to review the most recent literature identifying predictors of the transition to psychosis in those who are already assessed as being at risk.

RECENT FINDINGS

Multidomain models, in particular, integrated models of symptoms, social functioning, and cognition variables, achieve better predictive performance than individual factors. There are many methodological issues; however, several solutions have now been described in the literature. For youth who already have APS, predicting who may go on to later develop psychosis is possible. Several studies are underway in large consortiums that may overcome some of the methodological concerns and develop improved means of prediction.

Childhood urbanicity and hair steroid hormone levels in ten-year-old children

BACKGROUND

Research suggests that it may be more stressful for children to grow up in an urban area than in a rural area. Urbanicity may affect physiological stress system functioning as well as the timing of sexual maturation. The purpose of the current study was to investigate whether moderate urbanicity (current and childhood, ranging from rural areas to small cities) was associated with indices of long-term hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal axis functioning (cortisol, cortisone, dehydroepiandrosterone and progesterone levels) and whether sex moderated any associations.

METHOD

Children (N = 92) were all 10 years old and from the Dutch general population. Hair samples were collected and single segments (the three cm most proximal to the scalp) were assayed for concentrations of steroid hormones (LCMS/MS method). Neighborhood-level urbanicity and socioeconomic status were measured from birth through age ten years. Analyses were controlled for neighborhood- and family socioeconomic status, body mass index and season of sampling.

RESULTS

The results from multivariate analyses of variance showed no associations between current or childhood moderate urbanicity and hair steroid hormone concentrations. Interaction terms between moderate urbanicity and sex were not statistically significant.

CONCLUSIONS

Associations between urbanicity and steroid hormone levels may only be detectable in highly urban areas and/or during later stages of adolescence. Alternatively, our findings may have been due to most children being from families with a higher socioeconomic status.

Hypofunctional Dopamine Uptake and Antipsychotic Treatment-Resistant Schizophrenia

Antipsychotic treatment resistance in schizophrenia remains a major issue in psychiatry. Nearly 30% of patients with schizophrenia do not respond to antipsychotic treatment, yet the underlying neurobiological causes are unknown. All effective antipsychotic medications are thought to achieve their efficacy by targeting the dopaminergic system. Here we review early literature describing the fundamental mechanisms of antipsychotic drug efficacy, highlighting mechanistic concepts that have persisted over time. We then reconsider the original framework for understanding antipsychotic efficacy in light of recent advances in our scientific understanding of the dopaminergic effects of antipsychotics. Based on these new insights, we describe a role for the dopamine transporter in the genesis of both antipsychotic therapeutic response and primary resistance. We believe that this discussion will help delineate the dopaminergic nature of antipsychotic treatment-resistant schizophrenia.

Daily-life stress differentially impacts ventral striatal dopaminergic modulation of reward processing in first-degree relatives of individuals with psychosis

Emerging evidence shows that stress can impair the ability to learn from and pursue rewards, which in turn has been linked to motivational impairments characteristic of the psychotic disorder. Ventral striatal dopaminergic neurotransmission has been found to modulate reward processing, and appears to be disrupted by exposure to stress. We investigated the hypothesis that stress experienced in the everyday life has a blunting effect on reward-induced dopamine release in the ventral striatum of 16 individuals at a familial risk for psychosis compared to 16 matched control subjects. Six days of ecological momentary assessments quantified the amount of daily-life stress prior to [¹⁸F]fallypride PET imaging while performing a probabilistic reinforcement learning task. Relative to the controls, individuals at a familial risk for psychosis who encountered more daily-life stress showed significantly diminished extent of reward-induced dopamine release in the right ventral striatum, as well as poorer performance on the reward task. These findings provide the first neuromolecular evidence for stress-related deregulation of reward processing in familial predisposition to psychosis. The implication of daily-life stress in compromised modulation of reward function may facilitate the design of targeted neuropharmacological and ecological interventions.

Neurobiology and treatment of social cognition in schizophrenia: Bridging the bed-bench gap

Social cognition refers to the psychological processes involved in the perception, encoding, storage, retrieval, and regulation of information about others and ourselves. This process is essential for survival and reproduction in complex social environments. Recent evidence suggests that impairments in social cognition frequently occur in schizophrenia, mainly contributing to poor functional outcomes, including the inability to engage in meaningful work and maintain satisfying interpersonal relationships. With the ambiguous definition of social cognition, the neurobiology underlying impaired social cognition remains unknown, and the effectiveness of currently available intervention strategies in schizophrenia remain limited. Considering the advances and challenges of translational research for schizophrenia, social cognition has been considered a high-priority domain for treatment development. Here, we describe the current state of the framework, clinical concerns, and intervention approaches for social cognition in schizophrenia. Next, we introduce translatable rodent models associated with schizophrenia that allow the evaluation of different components of social behaviors, providing deeper insights into the neural substrates of social cognition in schizophrenia. Our review presents a valuable perspective that indicates the necessity of building bridges between basic and clinical science researchers for the development of novel therapeutic approaches in impaired social cognition in schizophrenia.

Ambient concentrations of NO2 and hospital admissions for schizophrenia

Objectives

Schizophrenia is a chronic and severe mental disorder affecting more than 21 million people worldwide. Short-term exposure to nitrogen dioxide (NO2) has been associated with hospital admissions (HAs) for mental disorders, but no study has evaluated the specific association of NO2 and schizophrenia. Additionally, the shape of the concentration–response (C–R) curve has not yet been assessed at present. This study aims to investigate the relationship between short-term exposure to NO2 and HAs for schizophrenia in Hefei, from 2014 to 2016. We also attempt to explore the C–R and the underlying effect modifiers of the association.

Methods

Daily number of HAs for schizophrenia was derived from the computerised medical record system of Anhui Mental Health Center. We used a time-series Poisson generalised linear regression combined with distributed lag non-linear models to model the NO2–schizophrenia relationship.

Results

A total of 11 373 HAs were identified during the study period. An increase in levels of NO2 was significantly associated with elevated schizophrenia HAs. The estimated relative risk per IQR increase in NO2 at lag 01 was 1.10 (95% CI 1.01 to 1.18). Greater association was observed in young patients (relative risk: 1.11, 95% CI 1.02 to 1.19). The modelled C–R curves of the NO2–schizophrenia relationship suggested possible threshold effects of NO2 for all ages combined, young patients, men and both seasons.

Conclusions

Short-term exposure to NO2 may be associated with increased schizophrenia HAs. Findings indicated potential threshold effects of NO2, which has important implications for health-based risk assessments.