Reduced hippocampal volume and hypothalamus-pituitary-adrenal axis function in first episode psychosis: evidence for sex differences

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.

Examining the psychobiological response to acute social stress across clinical stages and symptom trajectories in the early psychosis continuum

The stress-vulnerability model has been repeatedly highlighted in relation to the risk, onset and course of psychosis, and has been independently studied in clinical high-risk (CHR) and first-episode psychosis (FEP) populations. Notable in this literature, however, is that there are few studies directly comparing markers of stress response across progressive stages of illness. Here we examined the psychobiological response to the Trier Social Stress Test in 28 CHR (mean age 19.1) and 61 FEP (age 23.0) patients, in order to understand the stage(s) or trajectories in which differences in subjective stress or physiological response occur. The overall clinical sample had greater perceived stress and blunted cortisol (FEP + CHR, n = 89, age 21.7) compared with healthy controls (n = 45, age 22.9). Additional analyses demonstrated elevated heart rate and systolic blood pressure in FEP compared with CHR, but there were no further differences in physiological parameters (cortisol, heart rate, or blood pressure) between stage- or trajectory-based groups. Together, this suggests that individual stress response markers may differentially emerge at particular stages en route to psychosis - and demonstrates how stage-based analyses can shed light on the emergence and evolution of neurobiological changes in mental illness.

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.

Altered Sex Differences in Hippocampal Subfield Volumes in Schizophrenia

BACKGROUND AND HYPOTHESIS

The hippocampus is a heterogenous brain structure that differs between the sexes and has been implicated in the pathophysiology of psychiatric illnesses. Here, we explored sex and diagnostic group differences in hippocampal subfield volumes, in individuals with schizophrenia spectrum disorder (SZ), bipolar disorders (BD), and healthy controls (CTL).

STUDY DESIGN

One thousand and five hundred and twenty-one participants underwent T1-weighted magnetic resonance imaging (SZ, n = 452, mean age 30.7 ± 9.2 [SD] years, males 59.1%; BD, n = 316, 33.7 ± 11.4, 41.5%; CTL, n = 753, 34.1 ± 9.1, 55.6%). Total hippocampal, subfield, and intracranial volumes were estimated with Freesurfer (v6.0.0). Analysis of covariance and multiple regression models were fitted to examine sex-by-diagnostic (sub)group interactions in volume. In SZ and BD, separately, associations between volumes and clinical as well as cognitive measures were examined between the sexes using regression models.

STUDY RESULTS

Significant sex-by-group interactions were found for the total hippocampus, dentate gyrus, molecular layer, presubiculum, fimbria, hippocampal-amygdaloid transition area, and CA4, indicating a larger volumetric deficit in male patients relative to female patients when compared with same-sex CTL. Subgroup analyses revealed that this interaction was driven by males with schizophrenia. Effect sizes were overall small (partial η < 0.02). We found no significant sex differences in the associations between hippocampal volumes and clinical or cognitive measures in SZ and BD.

CONCLUSIONS

Using a well-powered sample, our findings indicate that the pattern of morphological sex differences in hippocampal subfields is altered in individuals with schizophrenia relative to CTL, due to higher volumetric deficits in males.

Sex differences in bipolar disorder: The dorsolateral prefrontal cortex as an etiopathogenic region

Bipolar disorder (BD) is worldwide a prevalent mental illness and a leading risk factor for suicide. Over the past three decades, it has been discovered that sex differences exist throughout the entire panorama of BD, but the etiologic regions and mechanisms that generate such differences remain poorly characterized. Available evidence indicates that the dorsolateral prefrontal cortex (DLPFC), a critical region that controls higher-order cognitive processing and mood, exhibits biological disparities between male and female patients with psychiatric disorders, which are highly correlated with the co-occurrence of psychotic symptoms. This review addresses the sex differences in BD concerning epidemiology, cognitive impairments, clinical manifestations, neuroimaging, and laboratory abnormalities. It also provides strong evidence linking DLPFC to the etiopathogenesis of these sex differences. We emphasize the importance of identifying gene signatures using human brain transcriptomics, which can depict sexually different variations, explain sex-biased symptomatic features, and provide novel targets for sex-specific therapeutics.

Relations of Lifetime Perceived Stress and Basal Cortisol With Hippocampal Volume Among Healthy Adolescents and Those at Clinical High Risk for Psychosis: A Structural Equation Modeling Approach

BACKGROUND

Hippocampal volume (HV) is sensitive to environmental influences. Under normative conditions in humans, HV increases linearly into childhood and asymptotes in early adulthood. Studies of humans and nonhuman animals have provided evidence of inverse relationships between several measures of stress and HV.

METHODS

Using structural equation modeling, this study aimed to characterize the relationships of age, basal cortisol, biological sex, and lifetime perceived stress with bilateral HV in a sample of healthy adolescents and adolescents at clinical high risk for psychosis (CHR-P) (N = 571, 43% female; age range = 12-19.9 years). This sample included 469 individuals at CHR-P and 102 healthy comparison participants from the combined baseline cohorts of the second and third NAPLS (North American Prodrome Longitudinal Study).

RESULTS

A structural model that constrained the individual effects of basal cortisol and perceived stress to single path coefficients, and freely estimated the effects of age and biological sex in group models, optimized model fit and parsimony relative to other candidate models. Significant inverse relationships between basal cortisol and bilateral HV were observed in adolescents at CHR-P and healthy comparison participants. Significant sex differences in bilateral HV were also observed, with females demonstrating smaller HV than males in both groups.

CONCLUSIONS

Multigroup structural equation modeling revealed heterogeneity in the relationships of age and biological sex with basal cortisol, lifetime perceived stress, and bilateral HV in individuals at CHR-P and healthy comparison participants. Moreover, the findings support previous literature indicating that elevated basal cortisol is a nonspecific risk factor for reduced HV.

Hippocampal subfields, daily stressors, and resting cortisol in individuals at clinical high-risk for psychosis

INTRODUCTION

The hippocampus, comprised of functionally distinct subfields, both regulates stress and is affected by it during psychosis pathogenesis. Hippocampal abnormalities are evident across psychosis spectrum and are associated with aberrant cortisol levels and greater environmental stressors exposure. These associations, particularly at the subfield-level, are poorly understood in individuals at clinical high-risk (CHR) for psychosis. This represents a significant literature gap given this critical pathogenetic period is characterized by an interplay between environmental stressors and biological susceptibility.

METHODS

A total of 121 participants including 51 CHR (mean age=18.61) and 70 healthy controls (HC; mean age=18.3) were enrolled in the study. Participants completed a structural scan, salivary cortisol assays, and a self-report measure assessing distress from daily stressors exposure (DSI). Hippocampal subfield segmentation was conducted using Freesurfer.

RESULTS

Smaller hippocampal subfields were associated with greater stress levels. Greater DSI was associated with lower volumes in CA1 (r = -0.38) and CA2/3 (r = -0.29), but not in CA4/DG (r = -0.28), presubiculum (r = -0.09), or subiculum (r = -0.17). Higher resting cortisol was associated with lower volumes in presubiculum (r = -0.4) but not subiculum (r = -0.22), CA1 (r = 0.08), CA2/3 (r = 0.1), or CA4/DG (r = -0.005). Regressions indicated effects for CA1 and DSI (β = 0.57, p = .03) and presubiculum and cortisol (β = 0.61, p = .02) are specific to CHR participants relative to HCs.

CONCLUSIONS

The findings provided insights into links between stress and brain vulnerability during psychosis-risk period. Regional differences highlighted potentially different mechanisms by which stress impacts specific subfields. Presubiculum may be more susceptible to the impact of early stress on HPA-axis and cornu amonis to acute stressors.

Higher lymphocyte count associated with larger hippocampal volume and fewer depressive symptoms in drug-na ïve first-episode psychosis

Circulating white blood cells (leucocytes), which form the peripheral immune system, are crucial in inflammatory processes but their role in brain structural change in schizophrenia has been scarcely studied. With this study we want to determine how and which type of white blood cells are associated with hippocampal volume (as a key structure in schi- zophrenia etiopathology) in first episode psychosis (FEP) patients. Moreover, to determine the association between white blood cells and clinical symptomatology, including positive and negative symptoms, cognition and depression. For this purpose fifty drug-naïve FEP were included in this study. All patients underwent an assessment at baseline and at 1 year follow-up, including sociodemographic and clinical variables (substance use, DUP, PANSS, GAF and CDSS). Fasting blood samples were obtained before administering any medication at baseline. Structural T1 MRI was performed at baseline and brain volumes were quantified. In the present study, higher lymphocyte count was associated with larger right hippocampal volume at baseline in FEP drug-naive patients. Higher lymphocyte count was associated with lower depressive symptomatology measured with CDSS and Marder depressive factor from PANSS at baseline and 1-year follow -up. These results suggest that lymphocytes may have a protective effect in hippocampal volume at baseli- ne in antipsychotic naïve FEP and also, are associated with a better depressive course over follow up. These results open the door to identify new biomarkers and therapeutic targets for patients with schizophrenia.

The Poly I:C maternal immune stimulation model shows unique patterns of brain metabolism, morphometry, and plasticity in female rats

Introduction: Prenatal infections are associated with an increased risk of the onset of schizophrenia. Rodent models of maternal immune stimulation (MIS) have been extensively used in preclinical studies. However, many of these studies only include males, omitting pathophysiological features unique to females. The aim of this study is to characterize the MIS model in female rats using positron emission tomography (PET), structural magnetic resonance imaging (MR), and neuroplasticiy studies. Methods: In gestational day 15, Poly I:C (or Saline) was injected into pregnant Wistar rats to induce the MIS model. Imaging studies: [¹⁸F]-fluoro-2-deoxy-D-glucose-PET scans of female-offspring were acquired at post-natal day (PND) 35 and PND100. Furthermore, T2-MR brain images were acquired in adulthood. Differences in FDG uptake and morphometry between groups were assessed with SPM12 and Regions of Interest (ROI) analyses. Ex vivo study: The density of parvalbumin expressing interneurons (PV), perineuronal nets (PNN), and parvalbumin expressing interneurons surrounded by perineuronal nets (PV-PNN) were evaluated in the prelimbic cortex and basolateral amygdala using confocal microscopy. ROIs and neuroplasticity data were analyzed by 2-sample T-test and 2-way-ANOVA analyses, respectively. Results: A significant increase in brain metabolism was found in all animals at adulthood compared to adolescence. MIS hardly modified brain glucose metabolism in females, highlighting a significant hypometabolism in the thalamus at adulthood. In addition, MIS induced gray matter (GM) enlargements in the pituitary, hippocampus, substantia nigra, and cingulate cortex, and GM shrinkages in some thalamic nuclei, cerebelar areas, and brainstem. Moreover, MIS induced white matter shrinkages in the cerebellum, brainstem and corpus callosum, along with cerebrospinal fluid enlargements in the lateral and 4th ventricles. Finally, MIS reduced the density of PV, PNN, and PV-PNN in the basolateral amygdala. Conclusion: Our work showed in vivo the differential pattern of functional and morphometric affectation in the MIS model in females, as well as the deficits caused at the synaptic level according to sex. The differences obtained highlight the relevance of including both sexes in psychiatric research in order to consider their pathophysiological particularities and successfully extend the benefits obtained to the entire patient population.

Cortisol awakening response in bipolar patients with comorbid type 2 diabetes mellitus

OBJECTIVES

Bipolar disorder (BD) is frequently associated with type 2 diabetes mellitus (T2DM). The functioning of the hypothalamic-pituitary-adrenal (HPA) axis has been never investigated in BD with respect to the glucose metabolic status. Therefore, we assessed the cortisol awakening response (CAR) in bipolar patients with or without comorbid T2DM.

METHODS

Twenty euglycemic bipolar patients [12 males and eight females; mean age (±SD): 47.4 ± 14.4 years; mean (±SD) duration of illness: 18.3 ± 12.1 years], 16 BD patients with T2DM [11 males and five females; mean age (±SD): 63.6 ± 12.8 years; mean (±SD) duration of bipolar illness: 17.1 ± 10.8 years; mean (±SD) duration of T2DM: 5.2 ± 5.3 years], 18 healthy subjects [seven males and 11 females; mean age (±SD): 45.0 ± 12.1 years] and 12 non-psychiatric subjects with T2DM [eight males and four females; mean age (±SD): 56.7 ± 11.2 years; mean (±SD) duration of T2DM: 5.2 ± 3.5 years] were recruited. Saliva cortisol was measured at awakening and after 15, 30, and 60 min.

RESULTS

With respect to both healthy controls and controls with T2DM, euglycemic and diabetic BD patients exhibited a CAR occurring at significantly lower levels. No significant difference emerged in the CAR between the two groups of bipolar patients. Controls with T2DM had an overall post-awakening cortisol production significantly higher than healthy controls.

CONCLUSIONS

Our results show that the CAR of patients with BD is reduced in terms of overall cortisol production but normal in terms of cortisol reactivity independently from the occurrence of comorbid T2DM. The dampened CAR points to a tuning down of the functioning of the HPA axis. in both euglycemic and diabetic BD patients, which may be a factor of vulnerability, since a preserved HPA axis functioning is essential to deal with stressors, which may precipitate affective episodes.

Stressful life events and psychosis: Gender differences

There is evidence that stressful events are associated with psychosis. This study aimed to explore sex differences in the association between stressful life events occurring during childhood and adulthood and psychosis. A total of 78 psychotic patients and 156 controls were enrolled. Childhood adversities were evaluated using a validated semi-structured interview and the Childhood Experience of Care and Abuse Questionnaire. Recent life events were recorded using a semi-structured interview with a normative and contextual approach. The diagnosis of psychosis was made according to Jablensky's criteria. χ² and t-test statistical analyses were run. Odds ratios were calculated in logistic regression. People with psychosis reported more exposure to both childhood adversities and recent events than the general population. An excess of childhood physical abuse was found among male psychotic patients, whereas both childhood sexual abuse and recent life events were overrepresented among female patients in comparison with the general population. There was a cumulative effect of stressful life events on psychosis, although it was stronger among females than in males. It is likely that there are gender differences in the association between stressful life events and psychosis.

Males and females with first episode psychosis present distinct profiles of social cognition and metacognition

Deficits in social cognition and metacognition impact the course of psychosis. Sex differences in social cognition and metacognition could explain heterogeneity in psychosis. 174 (58 females) patients with first-episode psychosis completed a clinical, neuropsychological, social cognitive, and metacognitive assessment. Subsequent latent profile analysis split by sex yielded two clusters common to both sexes (a Homogeneous group, 53% and 79.3%, and an Indecisive group, 18.3% and 8.6% of males and females, respectively), a specific male profile characterized by presenting jumping to conclusions (28.7%) and a specific female profile characterized by cognitive biases (12.1%). Males and females in the homogeneous profile seem to have a more benign course of illness. Males with jumping to conclusions had more clinical symptoms and more neuropsychological deficits. Females with cognitive biases were younger and had lower self-esteem. These results suggest that males and females may benefit from specific targeted treatment and highlights the need to consider sex when planning interventions.

A meta-analysis of blood and salivary cortisol levels in first-episode psychosis and high-risk individuals

Dysregulated cortisol responses and glucose metabolism have been reported in psychosis. We performed a random-effects meta-analysis of cortisol responses in first-episode psychosis (FEP) and psychosis risk states, taking into consideration glucose metabolism. A total of 47 studies were included. Unstimulated blood cortisol levels were significantly higher (g = 0.48, 95 %CI: 0.25-0.70, p < 0.001) in FEP, but not in psychosis risk states (g = 0.39, 95 %CI: -0.42-1.21, p = 0.342), compared to controls. Cortisol awakening response (CAR) was attenuated in FEP (g = -0.40, 95 %CI: -0.68 - -0.12, p = 0.006), but not in psychosis risk states (p = 0.433). Glucose and insulin levels were positively correlated with unstimulated blood cortisol levels in FEP. Our meta-analysis supports previous findings of elevated blood cortisol levels and attenuated CAR in FEP. Future research should focus on identifying the common denominators for alterations in stress hormones and glucose metabolism.

Cortisol and dehydroepiandrosterone sulfate in patients with schizophrenia spectrum disorders with respect to cognitive performance

Prolonged activation of the hypothalamic-pituitary-adrenal (HPA) axis associated with hypercortisolemia may lead to impairments of cognition in various populations. Dehydroepiandrosterone sulfate (DHEA-S) can protect the hippocampus from the detrimental effects of cortisol. However, this phenomenon has not been widely investigated in patients with schizophrenia spectrum disorders (SSD). Therefore, in this study, we aimed to assess the levels of cortisol, DHEA-S and cortisol/DHEA-S ratio in patients with SSD and healthy controls with respect to cognitive performance. Participants were 85 patients with SSD and 56 healthy controls, matched for age, sex and body-mass index. Cognitive performance was examined using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). The levels of hormones were measured in fasting serum samples. The levels of morning cortisol were significantly higher in patients with SSD compared to healthy controls, even after co-varying for potential confounding factors. There were no significant between-group differences in the levels of DHEA-S and cortisol/DHEA-S ratio. Higher levels of cortisol and greater cortisol/DHEA-S ratio were related to significantly lower RBANS scores of delayed memory in patients with SSD, but not in healthy controls after controlling for the effects of age, sex, BMI, the number of education years, cigarette smoking status and the dosage of antipsychotics. Our findings imply that elevated cortisol levels may contribute to impairments of memory processes in patients with SSD. However, longitudinal studies are needed to confirm causal associations.

•

Patients with schizophrenia show increased morning cortisol levels.

•

Our findings do not indicate altered levels of DHEA-S in schizophrenia.

•

Higher cortisol levels might be related to impaired delayed memory in schizophrenia.

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.

Neuroimaging Heterogeneity in Psychosis: Neurobiological Underpinnings and Opportunities for Prognostic and Therapeutic Innovation

Heterogeneity in symptom presentation, outcomes, and treatment response has long been problematic for researchers aiming to identify biological markers of schizophrenia or psychosis. However, there is increasing recognition that there may likely be no such general illness markers, which is consistent with the notion of a group of schizophrenia(s) that may have both shared and unique neurobiological pathways. Instead, strategies aiming to capitalize on or leverage such heterogeneity may help uncover neurobiological pathways that may then be used to stratify groups of patients for prognostic purposes or for therapeutic trials. A shift toward larger sample sizes with adequate statistical power to overcome small effect sizes and disentangle the shared variance among different brain-imaging or behavioral variables has become a priority for the field. In addition, recognition that two individuals with the same clinical diagnosis may be more different from each other (at brain, genetic, and behavioral levels) than from another individual in a different disorder or nonclinical control group-coupled with computational advances-has catapulted data-driven efforts forward. Emerging challenges for this new approach include longitudinal stability of new subgroups, demonstration of validity, and replicability. The "litmus test" will be whether computational approaches that are successfully identifying groups of patients who share features in common, more than current DSM diagnostic constructs, also provide better prognostic accuracy over time and in addition lead to enhancements in treatment response and outcomes. These are the factors that matter most to patients, families, providers, and payers.

Neurobiological mechanisms underlying sex-related differences in stress-related disorders: Effects of neuroactive steroids on the hippocampus

Men and women differ in their vulnerability to a variety of stress-related illnesses, but the underlying neurobiological mechanisms are not well understood. This is likely due to a comparative dearth of neurobiological studies that assess male and female rodents at the same time, while human neuroimaging studies often don't model sex as a variable of interest. These sex differences are often attributed to the actions of sex hormones, i.e. estrogens, progestogens and androgens. In this review, we summarize the results on sex hormone actions in the hippocampus and seek to bridge the gap between animal models and findings in humans. However, while effects of sex hormones on the hippocampus are largely consistent in animals and humans, methodological differences challenge the comparability of animal and human studies on stress effects. We summarise our current understanding of the neurobiological mechanisms that underlie sex-related differences in behavior and discuss implications for stress-related illnesses.

Sex as a Moderating Factor in the Relationship Between Hippocampal Volume and Sensory Gating in Patients With Schizophrenia

Building on the knowledge of sex differences in auditory sensory gating in schizophrenia and hippocampal involvement in sensory gating, this study aimed to investigate sex as a potential moderator of the association between hippocampal volume and P50 in schizophrenia. Auditory P50 gating and hippocampal volume were measured in 16 male and 15 female patients with schizophrenia. The correlations between hippocampal volume and P50 were analyzed in males and females separately, corrected for potential confounders, including age, duration of illness, and antipsychotic medication. Different associative patterns of hippocampal volume with P50 gating ratio and with P50 difference were found by sex. The results suggest sex may play a role in the physiology of sensory gating.

Interactive effects of corticotropin-releasing hormone receptor 1 gene and work stress on burnout in medical professionals in a Chinese Han population

BACKGROUND

Burnout is a worked-related stress syndrome caused by long-term exposure to a stressful environment. Dysregulation of the hypothalamic- pituitary- adrenal (HPA) axis may be involved in both stress and burnout; an evaluation of genetic polymorphisms which alter activity in the HPA may be predictive of how likely an environment is to produce burnout.

METHODS

Using a cross-sectional design, this study examined whether corticotrophin-releasing hormone receptor 1 (CRHR1) gene polymorphism rs110402 is a risk factor for burnout; further, it explores whether the interaction of stress × CRHR1 gene predicts burnout in the healthcare workers in a Chinese Han population. House and Rizzo's work stress scale, Sources of Pressure Scale and Maslach Burnout Inventory-General Survey were administered to 712 participants from a large general hospital in Beijing. The CRHR1 rs110402 polymorphism was genotyped in 376 participants.

RESULTS

Our results showed significant positive inter-correlations between stressor, work stress and depressive scores (all p < 0.001) with only one exception. Males, younger age and higher educational level were associated with burnout (all p < 0.05). The presence of the CRHR1 rs110402 genotype was not correlated with the presence of job stress or burnout. However, we found statistically significant interaction between CRHR1 rs110402 and job stress on burnout (p < 0.05). Individuals homozygous for the A allele reported significantly higher emotional exhaustion than G allele carriers in the high stress group.

LIMITATIONS

The sample was only chosen from the medical professions, and the sample size was relatively small. Only one polymorphism in CRHR1 gene was analyzed, while only about half of the total individuals were genotyped.

CONCLUSIONS

Our results suggest a close relationship between work-related stress and burnout and that the A allele of the CRHR1 rs110402 polymorphism may enhance feelings of emotional exhaustion when experiencing work-related stress.

The role of cortisol and prolactin in the pathogenesis and clinical expression of psychotic disorders

For many years, the study of the psychotic phenotpe and approach to treatment of schizophrenia has been focused on positive psychotic symptoms, although the functional outcome is more clearly associated with negative and cognitive symptoms. Recently, there has been a growing interest in identifying biomarkers associated with these symptoms at early stages of the illness, including the risk of psychosis in vulnerable individuals (at-risk mental states [ARMS]). In this paper, the role of cortisol and prolactin in the clinical expression of psychosis will be reviewed. In examination of the role of these hormones and the risk of developing a psychotic disorder in ARMS individuals, previous studies have suggested potential roles for both cortisol and prolactin. The study of cognitive abilities in recent-onset psychotic patients has suggested that affected cognitive domains differ depending upon the studied hormones: cortisol (processing speed, verbal and working memory) and prolactin (processing speed), with several studies suggesting that there are sex-differences in these associations. All of these results suggest that both cortisol and prolactin contribute to the pathogenesis and clinical expression of psychotic disorders.

Gender differences in childhood trauma in first episode psychosis: Association with symptom severity over two years

Early life adversity is associated with increased risk for psychosis onset and poor clinical outcome. Male compared to female patients often show a more severe course of psychotic illness. The aim of the present study was to investigate gender differences in childhood trauma (CT) and their impact on symptomatic and functional outcome following psychosis onset. The study included 210 patients (144 men, 66 women) diagnosed with a first-episode of psychosis (FEP). Early adversity was assessed with the Childhood Trauma Questionnaire. Psychotic symptoms and general functioning were rated with the Brief Psychiatric Rating Scale and Global Assessment of Functioning scale at baseline, 12 and 24 months of follow-up in an established early intervention service. Male patients reported higher rates of physical or emotional neglect, whereas female patients indicated significantly higher rates of emotional abuse. More severe CT was related to higher levels of depression in women and to negative symptoms in men. Distinct CT effects were observed on positive and negative symptom severity and global functioning in male patients at 24 months. Emotional abuse was the strongest predictor of depression in both genders. In male patients only, emotional abuse predicted positive symptom severity and impaired global functioning, whereas emotional neglect predicted more severe negative symptoms. Our results suggest differences in CT experiences in male and female FEP patients, with a more pronounced impact on longer-term outcome in male patients. The findings support the notion that sex differences in stress vulnerability account for the relatively poor illness course in male psychosis patients.

Is psychosis a multisystem disorder? A meta-review of central nervous system, immune, cardiometabolic, and endocrine alterations in first-episode psychosis and perspective on potential models

People with psychotic disorders show abnormalities in several organ systems in addition to the central nervous system (CNS); and this contributes to excess mortality. However, it is unclear how strong the evidence is for alterations in non-CNS systems at the onset of psychosis, how the alterations in non-CNS systems compare to those in the CNS, or how they relate to symptoms. Here, we consider these questions, and suggest potential models to account for findings. We conducted a systematic meta-review to summarize effect sizes for both CNS (focusing on brain structural, neurophysiological, and neurochemical parameters) and non-CNS dysfunction (focusing on immune, cardiometabolic, and hypothalamic-pituitary-adrenal (HPA) systems) in first-episode psychosis (FEP). Relevant meta-analyses were identified in a systematic search of Pubmed and the methodological quality of these was assessed using the AMSTAR checklist (A Measurement Tool to Assess Systematic Reviews). Case-control data were extracted from studies included in these meta-analyses. Random effects meta-analyses were re-run and effect size magnitudes for individual parameters were calculated, as were summary effect sizes for each CNS and non-CNS system. We also grouped studies to obtain overall effect sizes for non-CNS and CNS alterations. Robustness of data for non-CNS and CNS parameters was assessed using Rosenthal's fail-safe N. We next statistically compared summary effect size for overall CNSand overall non-CNS alterations, as well as for each organ system separately. We also examined how non-CNS alterations correlate CNS alterations, and with psychopathological symptoms. Case-control data were extracted for 165 studies comprising a total sample size of 13,440. For people with first episode psychosis compared with healthy controls, we observed alterations in immune parameters (summary effect size: g = 1.19), cardiometabolic parameters (g = 0.23); HPA parameters (g = 0.68); brain structure (g = 0.40); neurophysiology (g = 0.80); and neurochemistry (g = 0.43). Grouping non-CNS organ systems together provided an effect size for overall non-CNS alterations in patients compared with controls (g = 0.58), which was not significantly different from the overall CNS alterations effect size (g = 0.50). However, the summary effect size for immune alterations was significantly greater than that for brain structural (P < 0.001) and neurochemical alterations (P < 0.001), while the summary effect size for cardiometabolic alterations was significantly lower than neurochemical (P = 0.04), neurophysiological (P < 0.001), and brain structural alterations (P = 0.001). The summary effect size for HPA alterations was not significantly different from brain structural (P = 0.14), neurophysiological (P = 0.54), or neurochemical alterations (P = 0.22). These outcomes remained similar in antipsychotic naive sensitivity analyses. We found some, but limited and inconsistent, evidence that non-CNS alterations were associated with CNS changes and symptoms in first episode psychosis. Our findings indicate that there are robust alterations in non-CNS systems in psychosis, and that these are broadly similar in magnitude to a range of CNS alterations. We consider models that could account for these findings and discuss implications for future research and treatment.

Sex and gender differences in schizophrenic psychoses-a critical review

Many sex and gender differences in schizophrenic psychoses have been reported, but few have been soundly replicated. A stable finding is the later age of onset in women compared to men. Gender differences in symptomatology, comorbidity, and neurocognition seem to reflect findings in the general population. There is increasing evidence for estrogens being psychoprotective in women and for hypothalamic-pituitary-gonadal dysfunction in both sexes.More methodologically sound, longitudinal, multi-domain, interdisciplinary research investigating both sex (biological) and gender (psychosocial) factors is required to better understand the different pathogenesis and etiologies of schizophrenic psychoses in women and men, thereby leading to better tailored treatments and improved outcomes.

Prenatal stress and models explaining risk for psychopathology revisited: Generic vulnerability and divergent pathways

The present review revisits three hypothesized models that potentially could explain how prenatal maternal stress influences fetal development, birth outcomes, and subsequent developmental psychopathology. These models were mostly based on animal models, and new evidence for these models from human studies is evaluated. Furthermore, divergent trajectories from prenatal exposure to adversities to offspring affected outcomes are reviewed, including the comparison of studies on prenatal maternal stress with research on maternal substance use and maternal malnutrition during pregnancy. Finally, new directions in research on the mechanism underlying prenatal stress effects on human offspring is summarized. While it is concluded that there is abundant evidence for the negative associations between prenatal maternal stress and offspring behavioral, brain, and psychopathological outcomes in humans, there is no consistent evidence for specific mechanisms or specific outcomes in relation to stress exposure in utero. Rather, principles of multifinality and equifinality best describe the consequences for the offspring, suggesting a generic vulnerability and different pathways from prenatal adversities to developmental psychopathology, which complicates the search for underlying mechanisms. New and promising directions for research are provided to get a better understanding of how prenatal stress gets under the skin to affect fetal development.

Melatonin inhibits neuronal dysfunction-associated with neuroinflammation by atopic psychological stress in NC/Nga atopic-like mouse models

Atopic dermatitis (AD), also known as atopic eczema, is chronic pruritic skin disease. AD can increase psychological stress as well, increasing glucocorticoid release and exacerbating the associated symptoms. Chronic glucocorticoid elevation disturbs neuroendocrine signaling and can induce neuroinflammation, neurotoxicity, and cognitive impairment; however, it is unclear whether AD-related psychological stress elevates glucocorticoids enough to cause neuronal damage. Therefore, we assessed the effects of AD-induced stress in a mouse AD model. AD-related psychological stress increased astroglial and microglial activation, neuroinflammatory cytokine expression, and markers of neuronal loss. Notably, melatonin administration inhibited the development of skin lesions, scratching behavior, and serum IgE levels in the model mice, and additionally caused a significant reduction in corticotropin-releasing hormone responsiveness, and a significant reduction in neuronal damage. Finally, we produced similar results in a corticosterone-induced AD-like skin model. This is the first study to demonstrate that AD-related psychological stress increases neuroendocrine dysfunction, exacerbates neuroinflammation, and potentially accelerates other neurodegenerative disease states.

Linking persistent negative symptoms to amygdala-hippocampus structure in first-episode psychosis

Early persistent negative symptoms (PNS) following a first episode of psychosis (FEP) are linked to poor functional outcome. Reports of reduced amygdalar and hippocampal volumes in early psychosis have not accounted for heterogeneity of symptoms. Age is also seldom considered in this population, a factor that has the potential to uncover symptom-specific maturational biomarkers pertaining to volume and shape changes within the hippocampus and amygdala. T1-weighted volumes were acquired for early (N=21), secondary (N=30), non-(N=44) PNS patients with a FEP, and controls (N=44). Amygdalar-hippocampal volumes and surface area (SA) metrics were extracted with the Multiple Automatically Generated Templates (MAGeT)-Brain algorithm. Linear mixed models were applied to test for a main effect of group and age × group interactions. Early PNS patients had significantly reduced left amygdalar and right hippocampal volumes, as well as similarly lateralized negative age × group interactions compared to secondary PNS patients (P<0.017, corrected). Morphometry revealed decreased SA in early PNS compared with other patient groups in left central amygdala, and in a posterior region when compared with controls. Early and secondary PNS patients had significantly decreased SA as a function of age compared with patients without such symptoms within the right hippocampal tail (P<0.05, corrected). Significant amygdalar-hippocampal changes with age are linked to PNS after a FEP, with converging results from volumetric and morphometric analyses. Differential age trajectories suggest an aberrant maturational process within FEP patients presenting with PNS, which could represent dynamic endophenotypes setting these patients apart from their non-symptomatic peers. Studies are encouraged to parse apart such symptom constructs when examining neuroanatomical changes emerging after a FEP.

The Clinic for Assessment of Youth at Risk (CAYR): 10 years of service delivery and research targeting the prevention of psychosis in Montreal, Canada

AIM

In the context of an increasing focus on indicated prevention of psychotic disorders, we describe the operation of the Clinic for Assessment of Youth at Risk (CAYR) over 10 years, a specialized service for identification, monitoring and treatment of young individuals who meet ultra-high risk (UHR) criteria for psychosis, and its integration within the Prevention and Early Intervention Program for Psychosis (PEPP) in Montreal, Canada.

METHODS

We outline rationale, development, inclusion and exclusion criteria, assessment, services offered, community outreach and liaison with potential referral sites, and our research focus on risk and protective factors related to the neural diathesis-stress model of psychosis.

RESULTS

Between January 2005 and December 2014, CAYR has received 370 referrals and accepted 177 patients who met UHR criteria based on the Comprehensive Assessment for At Risk Mental States. Conversion rates to a first episode of psychosis were 11%. Our research findings point to high subjective stress levels, poor self-esteem, social support and coping skills, and a dysregulation of the hypothalamus-pituitary-adrenal axis during the high-risk phase.

CONCLUSIONS

Our efforts at community outreach have resulted in increasing numbers of referrals and patients accepted to CAYR, highlighting the relevance of and need for a high-risk programme in the Montreal area. Patients with psychotic symptoms can be immediately assigned to the first-episode psychosis clinic within PEPP, which has likely contributed to the low conversion rates observed in the UHR group. Our research findings on stress and protective factors emphasize the importance of psychosocial interventions for high-risk patients.

Interplay of hippocampal volume and hypothalamus-pituitary-adrenal axis function as markers of stress vulnerability in men at ultra-high risk for psychosis

BACKGROUND

Altered hypothalamus-pituitary-adrenal (HPA) axis function and reduced hippocampal volume (HV) are established correlates of stress vulnerability. We have previously shown an attenuated cortisol awakening response (CAR) and associations with HV specifically in male first-episode psychosis patients. Findings in individuals at ultra-high risk (UHR) for psychosis regarding these neurobiological markers are inconsistent, and assessment of their interplay, accounting for sex differences, could explain incongruent results.

METHOD

Study participants were 42 antipsychotic-naive UHR subjects (24 men) and 46 healthy community controls (23 men). Saliva samples for the assessment of CAR were collected at 0, 30 and 60 min after awakening. HV was determined from high-resolution structural magnetic resonance imaging scans using a semi-automatic segmentation protocol.

RESULTS

Cortisol measures and HV were not significantly different between UHR subjects and controls in total, but repeated-measures multivariate regression analyses revealed reduced cortisol levels 60 min after awakening and smaller left HV in male UHR individuals. In UHR participants only, smaller left and right HV was significantly correlated with a smaller total CAR (ρ = 0.42, p = 0.036 and ρ = 0.44, p = 0.029, respectively), corresponding to 18% and 19% of shared variance (medium effect size).

CONCLUSIONS

Our findings suggest that HV reduction in individuals at UHR for psychosis is specific to men and linked to reduced post-awakening cortisol concentrations. Abnormalities in the neuroendocrine circuitry modulating stress vulnerability specifically in male UHR subjects might explain increased psychosis risk and disadvantageous illness outcomes in men compared to women.

Hypothalamic-pituitary-adrenal axis activity and cognition in major depression: The role of remission status

OBJECTIVES

Neuropsychological deficits and hypothalamic-pituitary-adrenal (HPA) axis dysfunction have been described in major depressive disorder (MDD). We conducted an exploratory study to investigate the role of remission status in the relationship between HPA axis and cognition in MDD.

METHODS

Ninety-seven MDD patients (44 remitted, 53 non-remitted) and 97 healthy controls (HC) were evaluated. We measured verbal and visual memory, working memory, processing speed, attention, and executive function. Three HPA axis measures were assessed: cortisol awakening response (CAR), diurnal cortisol slope, and cortisol suppression ratio with 0.25mg of dexamethasone (DSTR). Multiple linear regression analyses were performed to study the relationship between cortisol measures and cognition while controlling for potential confounders. We conducted an overall analysis in all participants to compare both MDD-remitted and MDD non-remitted groups with respect to HC. Another analysis including MDD patients only was used to explore a moderating effect by remission status.

RESULTS

MDD patients showed poorer cognitive performance compared with HC, without significant differences between remitters and non-remitters. Cortisol measures did not differ between remitters and non-remitters. Although most HPA axis measures were not associated with cognitive dysfunction, we found significant associations between cognitive performance in MDD-remitters and cortisol measures for visual memory, processing speed and executive function. A significant moderating effect for remission status was found between cortisol diurnal slope (but neither CAR nor DSTR) and performance in processing speed or executive function.

CONCLUSIONS

Remission status in MDD appears to moderate the association between some cognitive domains (processing speed and executive function) and HPA axis activity.

Neuroanatomical and Symptomatic Sex Differences in Individuals at Clinical High Risk for Psychosis

Sex differences have been widely observed in clinical presentation, functional outcome and neuroanatomy in individuals with a first-episode of psychosis, and chronic patients suffering from schizophrenia. However, little is known about sex differences in the high-risk stages for psychosis. The present study investigated sex differences in cortical and subcortical neuroanatomy in individuals at clinical high risk (CHR) for psychosis and healthy controls (CTL), and the relationship between anatomy and clinical symptoms in males at CHR. Magnetic resonance images were collected in 26 individuals at CHR (13 men) and 29 CTLs (15 men) to determine total and regional brain volumes and morphology, cortical thickness, and surface area (SA). Clinical symptoms were assessed with the brief psychiatric rating scale. Significant sex-by-diagnosis interactions were observed with opposite directions of effect in male and female CHR subjects relative to their same-sex controls in multiple cortical and subcortical areas. The right postcentral, left superior parietal, inferior parietal supramarginal, and angular gyri [<5% false discovery rate (FDR)] were thicker in male and thinner in female CHR subjects compared with their same-sex CTLs. The same pattern was observed in the right superior parietal gyrus SA at the regional and vertex level. Using a recently developed surface-based morphology pipeline, we observed sex-specific shape differences in the left hippocampus (<5% FDR) and amygdala (<10% FDR). Negative symptom burden was significantly higher in male compared with female CHR subjects (p = 0.04) and was positively associated with areal expansion of the left amygdala in males (<5% FDR). Some limitations of the study include the sample size, and data acquisition at 1.5 T. This study demonstrates neuroanatomical sex differences in CHR subjects, which may be associated with variations in symptomatology in men and women with psychotic symptoms.

Hypothalamic-pituitary-adrenal axis measures and cognitive abilities in early psychosis: Are there sex differences?

INTRODUCTION

Measures of hypothalamic-pituitary-adrenal (HPA) axis activity such as increased diurnal cortisol levels or a blunted cortisol awakening response (CAR) have been associated with cognitive impairments in people with psychotic disorders. We aimed to explore whether there are sex differences in the relationship between HPA axis measures and cognition in early psychosis (EP).

METHODS

60 EP outpatients and 50 healthy subjects (HS) were assessed with the MATRICS Consensus Cognitive Battery. Saliva cortisol levels were determined at the neuropsychological assessment and on another day at 6 sampling times: awakening; 30' and 60' post-awakening; and 10:00h, 23:00h and 10:00h the day after the administration of 0.25mg of dexamethasone, which occurred at 23:00h. Three HPA axis measures were calculated: CAR, cortisol diurnal slope and cortisol suppression ratio of the dexamethasone suppression test (DST). Multiple linear regression analyses were conducted to explore the relationship between HPA axis measures and cognitive tasks while adjusting for covariates (education level, smoking, cannabis use, and cortisol levels at the cognitive assessment). Interactions between female sex, EP diagnosis and HPA axis measures were examined.

RESULTS

An increased CAR was associated with a poorer cognitive performance in EP women in processing speed and verbal memory. In contrast, a more flattened diurnal cortisol slope was associated with poorer functioning in the spatial working memory of EP women. DST suppression ratio was associated with better visual memory, without sex differences.

CONCLUSIONS

Our study suggests that there are sex differences in the relationship between HPA axis measures and cognitive abilities in EP.

Sex differences in morning cortisol in youth at ultra-high-risk for psychosis

Research suggests abnormalities in hypothalamic-pituitary-adrenal (HPA) axis function play an important role in the pathophysiology of psychosis. However, there is limited research on the biological stress system in young people at ultra high risk (UHR) for psychosis. Morning cortisol levels are particularly relevant to study in this context, as these markers reflect HPA regulation. This is the first examination of sex differences in morning cortisol levels in UHR individuals. Twenty-eight UHR and 22 matched healthy control participants were assessed in respect to symptoms and had home-based collection of salivary cortisol over three time points in the morning. It was predicted that the UHR participants would exhibit lower morning cortisol levels and lower cortisol would be associated with greater symptomatology (i.e. higher positive, negative, and depressive symptoms). Additionally, sex differences in morning cortisol levels were explored based on recent evidence suggesting that sex differences may play an important role in the exacerbation of psychosis. While there were no group differences in morning salivary cortisol secretion, there was a sex by time interaction among UHR individuals, such that only UHR males exhibited flat cortisol levels across two hours after awakening, whereas UHR females had a pattern of cortisol secretion similar to healthy controls, even among medication-free individuals (F=6.34, p=0.004). Cortisol AUC (area under the curve) across the three time points had a trend association (medium effect size; r=0.34, p=0.08) with depressive, but not positive or negative, symptom severity. These results stress the importance of considering sex differences in the psychosis-risk period, as they improve understanding of pathogenic processes.