Subtle fluctuations in psychotic phenomena as functional states of abnormal dopamine reactivity in individuals at risk

Comparison of male and female non-refugee immigrants with psychosis: clinical, sociodemographic, and migration-related differences and impact on stress

PURPOSE

To compare social, clinical, and migration-related factors between male and female immigrants with psychotic disorders and to determine the association between these variables and stress in the last year.

METHODS

We administered the Holmes and Rahe Social Readjustment Scale to evaluate psychological stress in 99 non-refugee immigrants (26 women, 73 men) who presented ≥ one psychotic episode (ICD-10 criteria). We compared the two groups in terms of sociodemographic, clinical, cultural, and migration-related variables. A multivariable analysis using a linear regression model (stepwise method) was performed to evaluate potential associations between these variables and stress.

RESULTS

Women were more likely to be married and divorced, had less access to welfare payments, and lower unemployment and homeless rates than men. The most common psychiatric diagnosis was psychosis not otherwise specified with more women being affected (61.5% in women vs. 45.2% in men), but the diagnosis of schizophrenia was more common in men (38.4% vs 15.4%). Both groups exhibited very high levels of stress in the past year (mean total distress score > 300). In women, stress was significantly associated with age at first migration and be a racialized person. By contrast, among men stress was significantly associated with language barrier and comorbidity with a physical disorder.

CONCLUSIONS

The results of this study reveal important differences between men and women immigrants. These findings underscore the importance of understanding how gender-specific roles and social expectations intersect with the timing and nature of migration to influence stress levels differently in immigrant women and men with psychotic disorders.

The daily association between positive affect and psychotic experiences in individuals along the early stages of the psychosis continuum

Introduction

Psychosis often develops gradually along a continuum of severity. Little is known about the role of protective factors such as positive affect (PA) in the development of psychotic experiences (PEs). This study investigated i) the temporal (between-day) and contemporaneous (within-day) daily associations between PA and PEs in individuals at different early clinical stages for psychosis and ii) whether these associations differed per clinical stage.

Methods

Daily diary data for 90 days came from 96 individuals at risk for psychosis, distributed over four subgroups defined according to the clinical staging model (stages 0-1b). We constructed multilevel models with PA as a predictor of PEs and vice versa. We investigated within- and between-person temporal and contemporaneous associations and tested whether these associations differed among early stages with multilevel moderation analyses.

Results

We found no within-person temporal effects between PA and PEs in either direction. Contemporaneously, current-day PA predicted current-day PEs (B = -0.14, p < 0.001) and vice versa (B = -0.61, p < 0.001). Between persons, more 90-day PA predicted fewer PEs in the temporal model (B = -0.14, p = 0.03). In addition, more 90-day PEs predicted PA in the temporal (B = -0.26, p < 0.001) and contemporaneous (B = -0.36, p < 0.001) models. The contemporaneous association between PA and PEs was stronger in individuals at ultra-high risk (UHR) for psychosis than in earlier stages.

Discussion

Our study supported a significant within-day, bidirectional relationship between PA and PEs. This suggests that a focus on PA and methods to improve PA may be an important addition to early intervention practices, particularly in those at UHR for psychosis.

Associations between disturbed sleep and attenuated psychotic experiences in people at clinical high risk for psychosis

BACKGROUND

Pre-diagnostic stages of psychotic illnesses, including 'clinical high risk' (CHR), are marked by sleep disturbances. These sleep disturbances appear to represent a key aspect in the etiology and maintenance of psychotic disorders. We aimed to examine the relationship between self-reported sleep dysfunction and attenuated psychotic symptoms (APS) on a day-to-day basis.

METHODS

Seventy-six CHR young people completed the Experience Sampling Methodology (ESM) component of the European Union Gene-Environment Interaction Study, collected through PsyMate® devices, prompting sleep and symptom questionnaires 10 times daily for 6 days. Bayesian multilevel mixed linear regression analyses were performed on time-variant ESM data using the brms package in R. We investigated the day-to-day associations between sleep and psychotic experiences bidirectionally on an item level. Sleep items included sleep onset latency, fragmentation, and quality. Psychosis items assessed a range of perceptual, cognitive, and bizarre thought content common in the CHR population.

RESULTS

Two of the seven psychosis variables were unidirectionally predicted by previous night's number of awakenings: every unit increase in number of nightly awakenings predicted a 0.27 and 0.28 unit increase in feeling unreal or paranoid the next day, respectively. No other sleep variables credibly predicted next-day psychotic symptoms or vice-versa.

CONCLUSION

In this study, the relationship between sleep disturbance and APS appears specific to the item in question. However, some APS, including perceptual disturbances, had low levels of endorsement amongst this sample. Nonetheless, these results provide evidence for a unidirectional relationship between sleep and some APS in this population.

The experience sampling methodology in psychosis risk states: A systematic review

The experience sampling method (ESM) is a structured diary technique, which is used to assess thoughts, mood and appraise subjective experiences in daily life. It has been recognized as a useful tool for understanding the characteristics, dynamics, and underlying mechanisms of prodromal symptoms of psychosis. The present systematic review aimed to provide a qualitative synthesis of findings provided by the ESM studies conducted in people with psychosis risk states. A systematic review of the MEDLINE, ERIC, Academic Search Ultimate, and Health Source: Nursing/Academic Edition databases, utilizing search terms related to the ESM and the risk of psychosis was conducted. Out of 1069 publication records identified, 77 studies met the inclusion criteria for the review. Data were synthesized around the following topics: 1) assessment of symptoms dynamics and social functioning; 2) assessment of the mechanisms contributing to the emergence of psychotic experiences and 3) assessment of stress sensitivity. The studies have shown that negative emotions are associated with subsequent development of paranoia. The tendency to draw hasty conclusions, aberrant salience, self-esteem, and emotion regulation were the most frequently reported mechanisms associated with the emergence of psychotic experiences. Studies using the ESM also provided evidence for the role of stress sensitivity, in the development of psychotic symptoms. The ESM has widely been applied to studies investigating psychosis risk states, using a variety of protocols. Findings from this systematic review might inform future studies and indicate potential targets for interventions.

The associations between daily reports of loneliness and psychotic experiences in the early risk stages for psychosis

AIM

Bi-directional associations between loneliness and psychotic experiences (PEs) have been reported, but the mechanisms underlying these associations are unknown. This study aims to explore associations between daily reports of loneliness and PEs, and test differences in this association across young adult individuals at different levels of risk for psychosis.

METHODS

We analysed 90-day diary data on loneliness and PEs from N = 96 participants (mean age 24.7, range 18-35, 77% female) divided into 4 subgroups, each indexing increased levels of risk for psychosis according to the clinical staging model: 'psychometric' (n = 25), 'low' (n = 27), 'mild' (n = 24), and 'ultra-high'(n = 20) risk. Multilevel vector autoregressive models examined within-day (contemporaneous) and between-day (temporal) associations between loneliness and PEs for the total sample. Next, these associations were compared across subgroups.

RESULTS

Loneliness and PEs were significantly associated contemporaneously (partial correlation B = 0.14) but not temporally. Subgroup membership moderated both contemporaneous and temporal associations. The contemporaneous association between loneliness and PEs was stronger in the low-risk subgroup compared to the mild-risk (B = -0.35, p < .01) and ultra-high-risk (B = -0.36, p < .01) subgroups. The temporal association between loneliness on the previous day and PEs on the current day was stronger in mild-risk subgroup compared to the ultra-high-risk subgroup (B = -0.03, p = .03). After adjusting for multiple testing, only the contemporaneous-but not the temporal-associations remained statistically significant.

CONCLUSIONS

Loneliness is associated with PEs in individuals at risk for psychosis, particularly in those with low to mild symptoms. Our findings tentatively suggest that especially individuals with low expressions of PEs may be more sensitive to social context, but future studies are needed to replicate and further unravel the potentially stage-specific interplay between social context and PEs.

The impact of childhood trauma and daily life experiences on emotional and psychotic symptom intensity in psychosis: An experience sampling study

Adverse childhood experiences create vulnerability to psychosis through biological and cognitive changes, and that may be observed as an increased emotional and psychotic response to daily life experiences in adulthood. This study aims to examine the effects of childhood maltreatment on psychotic patients' daily stress and emotional and psychotic intensity related to various experiences throughout the day. Daily activities and events, and emotional and psychotic intensity of forty-one psychotic patients were assessed with the Experience Sampling Method. The Childhood Trauma Questionnaire (CTQ) was used to evaluate childhood adversities. Multilevel regression analyses showed that all trauma subtypes, except for sexual abuse, were associated with increased psychosis and event-stress. Emotional maltreatment was the most associated trauma type with high negative and low positive affect and increased daily stress. Patients reported the highest stress and negative affect related to internal experiences but the lowest stress related to recreational actions. Social activities were also associated with higher positive affect and lower stress and psychosis, with the high CTQ group having greater stress in those activities. Our study demonstrates the negative impact of childhood trauma, especially emotional maltreatment, on daily stress and emotional and psychotic intensity in psychotic patients via different daily experiences.

Modelling the temporal interplay between stress and affective disturbances in pathways to psychosis: an experience sampling study

BACKGROUND

One putative psychological mechanism through which momentary stress impacts on psychosis in individuals with increased liability to the disorder is via affective disturbance. However, to date, this has not been systematically tested. We aimed to investigate whether (i) cross-sectional and temporal effects of momentary stress on psychotic experiences via affective disturbance, and (ii) the reverse pathway of psychotic experiences on stress via affective disturbance were modified by familial liability to psychosis.

METHODS

The Experience Sampling Method was used in a pooled data set of six studies with three groups of 245 individuals with psychotic disorder, 165 unaffected first-degree relatives, and 244 healthy control individuals to index familial liability. Multilevel moderated mediation models were fitted to investigate indirect effects across groups cross-sectionally and multilevel cross-lagged panel models to investigate temporal effects in the proposed pathways across two measurement occasions.

RESULTS

Evidence on indirect effects from cross-sectional models indicated that, in all three groups, effects of stress on psychotic experiences were mediated by negative affect and, vice versa, effects of psychotic experiences on stress were mediated by negative affect, with all indirect effects being weakest in relatives. Longitudinal modelling of data provided no evidence of temporal priority of stress in exerting its indirect effects on psychotic experiences via affective disturbance or, vice versa.

CONCLUSIONS

Our findings tentatively suggest a rapid vicious cycle of stress impacting psychotic experiences via affective disturbances, which does, however, not seem to be consistently modified by familial liability to psychosis.

Dopamine, Psychosis, and Symptom Fluctuation: A Narrative Review

It has been hypothesized since the 1960s that the etiology of schizophrenia is linked to dopamine. In the intervening 60 years, sophisticated brain imaging techniques, genetic/epigenetic advances, and new experimental animal models of schizophrenia have transformed schizophrenia research. The disease is now conceptualized as a heterogeneous neurodevelopmental disorder expressed phenotypically in four symptom domains: positive, negative, cognitive, and affective. The aim of this paper is threefold: (a) to review recent research into schizophrenia etiology, (b) to review papers that elicited subjective evidence from patients as to triggers and repressors of symptoms such as auditory hallucinations or paranoid thoughts, and (c) to address the potential role of dopamine in schizophrenia in general and, in particular, in the fluctuations in schizophrenia symptoms. The review also includes new discoveries in schizophrenia research, pointing to the involvement of both striatal neurons and glia, signaling pathway convergence, and the role of stress. It also addresses potential therapeutic implications. We conclude with the hope that this paper opens up novel avenues of research and new possibilities for treatment.

A systematic review and meta-analysis of the association between emotional stress reactivity and psychosis

AIM

Emotional stress reactivity may be a mediating factor in the association between trauma and psychosis. This review aimed to (i) identify, summarise and critically evaluate the link between emotional stress reactivity and psychotic experiences (ii) examine evidence for a 'dose-response' relationship between stress reactivity and psychosis in the wider psychosis phenotype (i.e., sub-clinical symptoms).

METHODS

Electronic database searches (PsychINFO, MEDLINE, EMBASE) were conducted for studies which investigated the link between stress reactivity and psychosis, psychotic symptoms, or a vulnerability to developing psychosis (wider phenotype). Cross-sectional, experimental and experience sampling method study designs were eligible for inclusion.

RESULTS

Fourty five eligible articles were identified (N participants = 8830). Narrative synthesis showed that increased emotional stress reactivity was associated with psychosis and subclinical psychotic experiences across all study designs, however, findings were inconsistent across studies. The preliminary meta-analysis (k = 4, n = 383) showed increases in emotional stress reactivity was associated with higher negative affect in response to event-related stress, in those with psychosis compared to controls (mean difference in beta coefficients = 0.05, 95% CI 0.02-0.08, p = .004). However, this difference was small with a considerable degree of heterogeneity (p = .001, I²  = 81%) so results should be interpreted with caution.

CONCLUSIONS

Overall, the evidence suggests that there is a link between emotional stress reactivity and psychosis in those with psychosis, those at high risk of developing psychosis and in relation to subclinical psychotic-like experiences in the general population.

Relationship between stressful life events, coping styles, and schizophrenia relapse

This study aimed to explore the relationship between stressful life events, coping styles, and schizophrenia relapse. The sample for this study included 248 patients with schizophrenia from a psychiatric outpatient clinic in Hunan Province, China. Stressful life events, occurrence of schizophrenia relapse, and coping style were assessed by the Scale for the Social Readjustment Rating, Brief Psychiatric Rating Scale, and Simplified Coping Style Questionnaire, respectively. Spearman correlation analysis and binary logistic regression analysis were adopted to explore the relationships among coping styles, schizophrenia relapse, and stressful life events. Stressful life events and negative coping exhibited significant positive association with schizophrenia relapse, while positive coping exhibited a significant negative association with schizophrenia relapse. Stressful life events and positive coping exerted significant effects on schizophrenia relapse, while negative coping did not. We also found that both positive coping and negative coping have moderating effects on the relationship between stressful life events and schizophrenia relapse, but the relationship is weak. The study highlighted the importance of interventions designed to reduce stressful life events, promote positive coping, and address negative coping in patients with schizophrenia.

A Compassion-Focused Ecological Momentary Intervention for Enhancing Resilience in Help-Seeking Youth: Uncontrolled Pilot Study

BACKGROUND

Digital interventions offer new avenues for low-threshold prevention and treatment in young people. Ecological momentary interventions (EMIs) represent a powerful approach that allows for adaptive, real-time, and real-world delivery of intervention components in daily life by real-time processing of ecological momentary assessment (EMA) data. Compassion-focused interventions (CFIs) may be particularly amenable to translation into an EMI to strengthen emotional resilience and modify putative risk mechanisms, such as stress sensitivity, in the daily lives of young help-seeking individuals.

OBJECTIVE

This study aims to investigate the feasibility, safety, and initial therapeutic effects of a novel, accessible, transdiagnostic, ecological momentary CFI for improving emotional resilience to stress (EMIcompass).

METHODS

In this uncontrolled pilot study, help-seeking youth with psychotic, depressive, or anxiety symptoms were offered the EMIcompass intervention in addition to treatment as usual. The EMIcompass intervention consisted of a 3-week EMI (including enhancing, consolidating, and EMA-informed interactive tasks) administered through a mobile health app and three face-to-face sessions with a trained psychologist intended to provide guidance and training on the CFI exercises presented in the app (ie, training session, follow-up booster session, and review session).

RESULTS

In total, 10 individuals (mean age 20.3 years, SD 3.8; range 14-25) were included in the study. Most (8/10, 80%) participants were satisfied and reported a low burden of app usage. No adverse events were observed. In approximately one-third of all EMAs, individuals scored high on stress, negative affect, or threat anticipation during the intervention period, resulting in real-time, interactive delivery of the CFI intervention components in addition to weekly enhancing and daily consolidating tasks. Although the findings should be interpreted with caution because of the small sample size, reduced stress sensitivity, momentary negative affect, and psychotic experiences, along with increased positive affect, were found at postintervention and the 4-week follow-up. Furthermore, reductions in psychotic, anxiety, and depressive symptoms were found (r=0.30-0.65).

CONCLUSIONS

Our findings provide evidence on the feasibility and safety of the EMIcompass intervention for help-seeking youth and lend initial support to beneficial effects on stress sensitivity and mental health outcomes. An exploratory randomized controlled trial is warranted to establish the feasibility and preliminary evidence of its efficacy.

Disrupted upregulation of salience network connectivity during acute stress in siblings of schizophrenia patients

BACKGROUND

An adaptive neural stress response is essential to adequately cope with a changing environment. It was previously argued that sympathetic/noradrenergic activity during acute stress increases salience network (SN) connectivity and reduces executive control network (ECN) connectivity in healthy controls, with opposing effects in the late aftermath of stress. Altered temporal dynamics of these networks in response to stress are thought to play a role in the development of psychopathology in vulnerable individuals.

METHODS

We exposed male healthy controls (n = 40, mean age = 33.9) and unaffected siblings of schizophrenia patients (n = 39, mean age = 33.2) to the stress or control condition of the trier social stress test and subsequently investigated resting state functional connectivity of the SN and ECN directly after and 1.5 h after stress.

RESULTS

Acute stress resulted in increased functional connectivity within the SN in healthy controls, but not in siblings (group × stress interaction pfwe < 0.05). In the late aftermath of stress, stress reduced functional connectivity within the SN in both groups. Moreover, we found increased functional connectivity between the ECN and the cerebellum in the aftermath of stress in both healthy controls and siblings of schizophrenia patients.

CONCLUSIONS

The results show profound differences between siblings of schizophrenia patients and controls during acute stress. Siblings lacked the upregulation of neural resources necessary to quickly and adequately cope with a stressor. This points to a reduced dynamic range in the sympathetic response, and may constitute a vulnerability factor for the development of psychopathology in this at-risk group.

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.

Perceived Stress and Life Events in Patients Affected by Schizophrenia and Schizoaffective and Bipolar Disorder: Is There a Role for Self-Reported Basic Symptoms?

INTRODUCTION

The stress-diathesis model of psychotic disorders describes, in vulnerable individuals, the role of psychosocial stress in the onset and exacerbation of psychotic symptoms. Another interesting approach to the study of vulnerability in the development of psychosis is represented by the basic symptoms concept.

OBJECTIVE

The present study aims at proposing an integration between these two models and investigating possible associations between psychotic symptoms, basic symptoms, perceived stress, and life events in a sample of patients affected by schizophrenia (SZ), schizoaffective (SA), and bipolar disorder with and without psychotic symptoms.

METHODS

112 patients were recruited in two university hospitals. Severity of psychiatric symptoms (Positive and Negative Syndrome Scale, PANSS), basic symptoms (Frankfurt Complaint Questionnaire, FCQ), perceived stress (Stress-related Vulnerability Scale, SVS), and life events (Paykel's interview for recent life events) were assessed.

RESULTS

Patients affected by bipolar disorder (both with and without psychotic symptoms) showed a higher number of independent life events (p < 0.01) and tended to report more frequently at least 1 life event in the previous 6 months (p < 0.01) than patients affected by SZ or SA disorder. No differences emerged between the study groups in perceived stress nor in measures of basic symptoms. In the whole sample, a logistic regression analysis showed that the SVS total score (p < 0.05) and PANSS total score (p < 0.001) were associated with the presence of psychotic symptoms.

CONCLUSIONS

In the study sample, life events and basic symptoms did not play a major role in influencing psychotic symptoms, compared to the subjective perception of stress and the severity of psychopathology. Taken together, these results can be informative for rehabilitation therapies aimed at enhancing resilience and coping strategies in this vulnerable group of patients.

Compliance and Retention With the Experience Sampling Method Over the Continuum of Severe Mental Disorders: Meta-Analysis and Recommendations

Background

Despite the growing interest in the experience sampling method (ESM) as a data collection tool for mental health research, the absence of methodological guidelines related to its use has resulted in a large heterogeneity of designs. Concomitantly, the potential effects of the design on the response behavior of the participants remain largely unknown.

Objective

The objective of this meta-analysis was to investigate the associations between various sample and design characteristics and the compliance and retention rates of studies using ESM in mental health research.

Methods

ESM studies investigating major depressive disorder, bipolar disorder, and psychotic disorder were considered for inclusion. Besides the compliance and retention rates, a number of sample and design characteristics of the selected studies were collected to assess their potential relationships with the compliance and retention rates. Multilevel random/mixed effects models were used for the analyses.

Results

Compliance and retention rates were lower for studies with a higher proportion of male participants (P<.001) and individuals with a psychotic disorder (P<.001). Compliance was positively associated with the use of a fixed sampling scheme (P=.02), higher incentives (P=.03), higher time intervals between successive evaluations (P=.02), and fewer evaluations per day (P=.008), while no significant associations were observed with regard to the mean age of the sample, the study duration, or other design characteristics.

Conclusions

The findings demonstrate that ESM studies can be carried out in mental health research, but the quality of the data collection depends upon a number of factors related to the design of ESM studies and the samples under study that need to be considered when designing such protocols.

Stress precedes negative symptom exacerbations in clinical high risk and early psychosis: A time-lagged experience sampling study

The experience sampling method (ESM) has revealed associations between fluctuations in stress and positive symptoms in psychosis. It is unknown, however, how negative symptoms including anhedonia respond to stress. Stress is divided according to its source: event-related stress stemming from negative events, and activity-related stress stemming from engaging in tasks beyond one's skill or control. Anhedonia is divided into consummatory and anticipatory anhedonia, reflecting a lack of pleasure in current and expected activities. This study uses ESM to determine whether each form of anhedonia increases in response to stress. Antipsychotic-naïve individuals with first episode psychosis (n = 39), clinical high-risk states for psychosis (n = 44), and healthy controls (n = 34) responded to daily prompts on a palmtop computer for up to ten days by indicating levels of stress and anhedonia. Time-lagged multilevel modelling was employed to explore increases in anhedonia following increases in stress while controlling for prior levels of anhedonia. Mean levels of anhedonia were also compared across groups. Only activity-related stress produced increases in anhedonia. This effect did not vary between groups. Clinical groups showed greater overall levels of anhedonia than healthy controls, but did not differ from each other. Anhedonia responds only to activity-related stressors, suggesting that this form of stress has a specific causal role in anhedonia. The results also provide further evidence for global increases in anhedonia in antipsychotic-naïve psychosis spectrum individuals.

Poor sleep quality predicts psychotic-like symptoms: an experience sampling study in young adults with schizotypal traits

OBJECTIVE

Psychotic-like experiences (PLEs) are unusual experiences such as perceptual abnormalities and delusional-like thoughts that resemble the symptoms of psychosis at the sub-clinical level. PLEs are associated with sleep complaints in healthy and clinical samples; however, evidence for day-to-day associations between poor sleep and subsequent PLEs under naturalistic conditions is scarce. We hypothesized that poor sleep quality would predict next days' PLEs, and vice versa, daytime PLEs would be associated with worse subsequent sleep quality.

METHOD

Seventy-three university students with moderate to high levels of positive schizotypy participated in an experience sampling study. Participants rated their sleep each morning, as well as PLEs and affective states during the day over 3 weeks.

RESULTS

Multilevel regression models indicated that poor sleep quality predicted increased PLEs the following day. Poor sleep was linked to negative daytime mood that partially mediated the associations between sleep quality and next days' PLEs. Furthermore, PLEs were enhanced in the evening as compared to daytime reports. The prediction of poor sleep quality by previous days' PLEs was negligible.

CONCLUSIONS

The results are consistent with the position that sleep-related interventions might reduce the risk of psychosis, especially in individuals that tend to experience psychotic-like phenomena and negative affect.

Liberal Acceptance Bias, Momentary Aberrant Salience, and Psychosis: An Experimental Experience Sampling Study

Cognitive models of psychosis posit that reasoning biases are an important mechanism contributing to the formation of psychotic symptoms, in part through transforming anomalous experiences of aberrant salience into frank psychotic symptoms. This study aimed to investigate the interplay of liberal acceptance (LA) bias, which is a specific type of reasoning bias, and momentary aberrant salience in the development of paranoid and psychotic experiences in daily life in first-episode psychosis patients (FEP), at-risk mental state participants (ARMS), and controls. We used a novel experimental Experience Sampling Methodology (eESM) task for measuring LA bias (ie, decisions based on low probability estimates) and ESM measures of momentary aberrant salience and paranoid and psychotic experiences in 51 FEP, 46 ARMS, and 53 controls. We found evidence that LA bias was more likely to occur in FEP than in controls. Further, LA bias was associated with psychotic and paranoid experiences (all P < .007) and modified the association between momentary aberrant salience and psychotic experiences (χ2(df) = 7.4(2), P = .025) in ARMS, such that momentary salience was associated with more intense psychotic experiences in the presence of LA bias in ARMS, but not in FEP and controls. Our findings suggest that LA bias may be central for anomalous experiences such as momentary aberrant salience to increase intensity of psychotic experiences in at-risk individuals. Further, LA bias appears to be more likely to be present, but not directly linked to current intensity of psychotic experiences, in treated FEP. Novel eESM tasks open new avenues for targeting psychological processes under real-world conditions.

At-risk individuals display altered brain activity following stress

Stress is a major risk factor for almost all psychiatric disorders, however, the underlying neurobiological mechanisms remain largely elusive. In healthy individuals, a successful stress response involves an adequate neuronal adaptation to a changing environment. This adaptive response may be dysfunctional in vulnerable individuals, potentially contributing to the development of psychopathology. In the current study, we investigated brain responses to emotional stimuli following stress in healthy controls and at-risk individuals. An fMRI study was conducted in healthy male controls (N = 39) and unaffected healthy male siblings of schizophrenia patients (N = 39) who are at increased risk for the development of a broad range of psychiatric disorders. Brain responses to pictures from the International Affective Picture System (IAPS) were measured 33 min after exposure to stress induced by the validated trier social stress test (TSST) or a control condition. Stress-induced levels of cortisol, alpha-amylase, and subjective stress were comparable in both groups. Yet, stress differentially affected brain responses of schizophrenia siblings versus controls. Specifically, control subjects, but not schizophrenia siblings, showed reduced brain activity in key nodes of the default mode network (PCC/precuneus and mPFC) and salience network (anterior insula) as well as the STG, MTG, MCC, vlPFC, precentral gyrus, and cerebellar vermis in response to all pictures following stress. These results indicate that even in the absence of a psychiatric disorder, at-risk individuals display abnormal functional activation following stress, which in turn may increase their vulnerability and risk for adverse outcomes.

Distress, Impairment and the Extended Psychosis Phenotype: A Network Analysis of Psychotic Experiences in an US General Population Sample

It has been proposed that subclinical psychotic experiences (PEs) may causally impact on each other over time and engage with one another in patterns of mutual reinforcement and feedback. This subclinical network of experiences in turn may facilitate the onset of psychotic disorder. PEs, however, are not inherently distressing, nor do they inevitably lead to impairment. The question arises therefore, whether nondistressing PEs, distressing PEs, or both, meaningfully inform an extended psychosis phenotype. The current study first aimed to exploit valuable ordinal data that captured the absence, occurrence and associated impairment of PEs in the general population to construct a general population based severity network of PEs. The study then aimed to partition the available ordinal data into 2 sets of binary data to test whether an occurrence network comprised of PE data denoting absence (coded 0) and occurrence/impairment (coded 1) was comparable to an impairment network comprised of binary PE data denoting absence/occurrence (coded 0) and impairment (coded 1). Networks were constructed using state-of-the-art regularized pairwise Markov Random Fields (PMRF). The severity network revealed strong interconnectivity between PEs and nodes denoting paranoia were among the most central in the network. The binary PMRF impairment network structure was similar to the occurrence network, however, the impairment network was characterized by significantly stronger PE interconnectivity. The findings may help researchers and clinicians to consider and determine how, when, and why an individual might transition from experiences that are nondistressing to experiences that are more commonly characteristic of psychosis symptomology in clinical settings.

Study protocol for a prospective cohort study examining the predictive potential of dynamic symptom networks for the onset and progression of psychosis: the Mapping Individual Routes of Risk and Resilience (Mirorr) study

INTRODUCTION

Our current ability to predict the course and outcome of early psychotic symptoms is limited, hampering timely treatment. To improve our understanding of the development of psychosis, a different approach to psychopathology may be productive. We propose to reconceptualise psychopathology from a network perspective, according to which symptoms act as a dynamic, interconnected system, impacting on each other over time and across diagnostic boundaries to form symptom networks. Adopting this network approach, the Mapping Individual Routes of Risk and Resilience study aims to determine whether characteristics of symptom networks can predict illness course and outcome of early psychotic symptoms.

METHODS AND ANALYSIS

The sample consists of n=100 participants aged 18-35 years, divided into four subgroups (n=4×25) with increasing levels of severity of psychopathology, representing successive stages of clinical progression. Individuals representing the initial stage have a relatively low expression of psychotic experiences (general population), whereas individuals representing the end stage are help seeking and display a psychometric expression of psychosis, putting them at ultra-high risk for transition to psychotic disorder. At baseline and 1-year follow-up, participants report their symptoms, affective states and experiences for three consecutive months in short, daily questionnaires on their smartphone, which will be used to map individual networks. Network parameters, including the strength and directionality of symptom connections and centrality indices, will be estimated and associated to individual differences in and within-individual progression through stages of clinical severity and functioning over the next 3 years.

ETHICS AND DISSEMINATION

The study has been approved by the local medical ethical committee (ABR no. NL52974.042.15). The results of the study will be published in (inter)national peer-reviewed journals, presented at research, clinical and general public conferences. The results will assist in improving and fine-tuning dynamic models of psychopathology, stimulating both clinical and scientific progress.

TRIAL REGISTRATION NUMBER

NTR6205 ; Pre-results.

Stress sensitivity as a putative mechanism linking childhood trauma and psychopathology in youth's daily life

OBJECTIVE

Childhood trauma (CT) is associated with a range of psychopathologies, including psychosis. However, evidence on underlying mechanisms remains limited. The study aimed to investigate whether CT impacts on youth mental health by modifying sensitivity to stress in daily life.

METHOD

The experience sampling method (ESM) was used to measure momentary stress, negative affect and psychotic experiences in 99 adolescents and young adults (43 help-seeking service users, 16 siblings and 40 controls). Before ESM assessments, CT and depressive, anxiety and psychotic symptoms were assessed.

RESULTS

Stress sensitivity, that is, the association between momentary stress and (i) negative affect and (ii) psychotic experiences, was modified by physical and emotional abuse and, partially, emotional and physical neglect, but not sexual abuse in service users and controls. While there was strong evidence for increased stress sensitivity in service users when high vs. low levels of CT were compared, a pattern of resilience was evident in controls, with attenuated, or no differences in, stress sensitivity in those with high vs. low CT levels. Less consistent findings were observed in siblings.

CONCLUSIONS

Stress sensitivity may be an important risk and resilience mechanism through which CT impacts on mental health in youth.

The Role of Genes, Stress, and Dopamine in the Development of Schizophrenia

The dopamine hypothesis is the longest standing pathoetiologic theory of schizophrenia. Because it was initially based on indirect evidence and findings in patients with established schizophrenia, it was unclear what role dopamine played in the onset of the disorder. However, recent studies in people at risk of schizophrenia have found elevated striatal dopamine synthesis capacity and increased dopamine release to stress. Furthermore, striatal dopamine changes have been linked to altered cortical function during cognitive tasks, in line with preclinical evidence that a circuit involving cortical projections to the striatum and midbrain may underlie the striatal dopamine changes. Other studies have shown that a number of environmental risk factors for schizophrenia, such as social isolation and childhood trauma, also affect presynaptic dopaminergic function. Advances in preclinical work and genetics have begun to unravel the molecular architecture linking dopamine, psychosis, and psychosocial stress. Included among the many genes associated with risk of schizophrenia are the gene encoding the dopamine D2 receptor and those involved in the upstream regulation of dopaminergic synthesis, through glutamatergic and gamma-aminobutyric acidergic pathways. A number of these pathways are also linked to the stress response. We review these new lines of evidence and present a model of how genes and environmental factors may sensitize the dopamine system so that it is vulnerable to acute stress, leading to progressive dysregulation and the onset of psychosis. Finally, we consider the implications for rational drug development, in particular regionally selective dopaminergic modulation, and the potential of genetic factors to stratify patients.

Reactivity to social stress in ethnic minority men

Repeated exposures to social exclusion, through a process of sensitization, may result in larger responses to experiences of social stress. The current study tested the hypothesis that healthy Moroccan-Dutch men respond stronger to social stress than Dutch controls 1) in daily life, and 2) in an experimental set-up. A general population sample of 50 Moroccan-Dutch and 50 Dutch young adult males were tested with 1) the Experience Sampling Method, a structured diary technique, assessing reactivity to social stress in daily life, and 2) an experimental exposure to social peer evaluation. No group differences were found in affective or psychotic reactivity to daily social stress. When exposed to a negative social evaluation in the lab, a blunted affective response was found in the Moroccan-Dutch compared to the Dutch group, whereas the psychotic response did not differ significantly between groups. In conclusion, healthy Moroccan-Dutch men are not more sensitive to social stress than healthy Dutch men. Instead, the blunted affective response of Moroccan-Dutch men to peer evaluation may signify habituation rather than sensitization.

Incidence of stressful life events and influence of sociodemographic and clinical variables on the onset of first-episode psychosis

This study presents a quantitative analysis of the incidence of stressful life events (SLEs) and the variables gender, age at onset, family history and psychotic symptoms in patients with first-episode psychosis (FEP). A descriptive, cross-sectional methodology was used to interview 68 patients with FEP between 13 and 47 years of age. The Psychiatric Epidemiology Research Interview Life Events Scale collected one-year period prior to onset of FEP - used to analyse the subcategories academic, work, love and marriage, children, residence, legal affairs, finances and social activities-, Positive and Negative Syndrome Scale, and Clinical Global Impression-Schizophrenia scale were used to assess the relevance of certain SLEs during adolescence. Age at onset showed a significant negative correlation with the categories academic and social activities. By contrast, it showed a positive correlation with work and children. A significant relationship was found between paternal family history and social activities and between maternal family history and academic and love and marriage. Finally, an inverse relationship was observed between negative symptoms and the categories children and finance. Depressive symptoms were significantly correlated with the category academic. Our results show the importance of SLEs during adolescence and suggest that there is a clear need to develop preventive actions that promote effective strategies for dealing with the accumulation of psychosocial stress.

Stress Sensitivity and Psychotic Experiences in 39 Low- and Middle-Income Countries

Stress has a central role in most theories of psychosis etiology, but the relation between stress and psychosis has rarely been examined in large population-level data sets, particularly in low- and middle-income countries. We used data from 39 countries in the World Health Survey (n = 176 934) to test the hypothesis that stress sensitivity would be associated with psychotic experiences, using logistic regression analyses. Respondents in low-income countries reported higher stress sensitivity (P < .001) and prevalence of psychotic experiences (P < .001), compared to individuals in middle-income countries. Greater stress sensitivity was associated with increased odds for psychotic experiences, even when adjusted for co-occurring anxiety and depressive symptoms: adjusted odds ratio (95% CI) = 1.17 (1.15-1.19) per unit increase in stress sensitivity (range 2-10). This association was consistent and significant across nearly every country studied, and translated into a difference in psychotic experience prevalence ranging from 6.4% among those with the lowest levels of stress sensitivity up to 22.2% among those with the highest levels. These findings highlight the generalizability of the association between psychosis and stress sensitivity in the largest and most globally representative community-level sample to date, and support the targeting of stress sensitivity as a potential component of individual- and population-level interventions for psychosis.

Redox dysregulation, neuroinflammation, and NMDA receptor hypofunction: A "central hub" in schizophrenia pathophysiology?

Accumulating evidence points to altered GABAergic parvalbumin-expressing interneurons and impaired myelin/axonal integrity in schizophrenia. Both findings could be due to abnormal neurodevelopmental trajectories, affecting local neuronal networks and long-range synchrony and leading to cognitive deficits. In this review, we present data from animal models demonstrating that redox dysregulation, neuroinflammation and/or NMDAR hypofunction (as observed in patients) impairs the normal development of both parvalbumin interneurons and oligodendrocytes. These observations suggest that a dysregulation of the redox, neuroimmune, and glutamatergic systems due to genetic and early-life environmental risk factors could contribute to the anomalies of parvalbumin interneurons and white matter in schizophrenia, ultimately impacting cognition, social competence, and affective behavior via abnormal function of micro- and macrocircuits. Moreover, we propose that the redox, neuroimmune, and glutamatergic systems form a "central hub" where an imbalance within any of these "hub" systems leads to similar anomalies of parvalbumin interneurons and oligodendrocytes due to the tight and reciprocal interactions that exist among these systems. A combination of vulnerabilities for a dysregulation within more than one of these systems may be particularly deleterious. For these reasons, molecules, such as N-acetylcysteine, that possess antioxidant and anti-inflammatory properties and can also regulate glutamatergic transmission are promising tools for prevention in ultra-high risk patients or for early intervention therapy during the first stages of the disease.

Social Stress and Psychosis Risk: Common Neurochemical Substrates?

Environmental risk factors have been implicated in the etiology of psychotic disorders, with growing evidence showing the adverse effects of migration, social marginalization, urbanicity, childhood trauma, social defeat, and other adverse experiences on mental health in vulnerable populations. Collectively, social stress may be one mechanism that could link these environmental risk factors. The exact mechanism(s) by which social stress can affect brain function, and in particular the molecular targets involved in psychosis (such as the dopaminergic (DA) system), is (are) not fully understood. In this review, we will discuss the interplay between social environmental risk factors and molecular changes in the human brain; in particular, we will highlight the impact of social stress on three specific neurochemical systems: DA, neuroinflammation/immune, and endocannabinoid (eCB) signaling. We have chosen the latter two molecular pathways based on emerging evidence linking schizophrenia to altered neuroinflammatory processes and cannabis use. We further identify key developmental periods in which social stress interacts with these pathways, suggesting window(s) of opportunities for novel interventions. Taken together, we suggest that they may have a key role in the pathogenesis and disease progression, possibly provide novel treatment options for schizophrenia, and perhaps even prevent it.

Psychotic reactions to daily life stress and dopamine function in people with severe hearing impairment

BACKGROUND

Minor stresses measured in daily life have repeatedly been associated with increased momentary psychotic experiences, both in individuals with psychotic disorders and in persons who are genetically at an increased risk for these disorders. Severe hearing impairment (SHI) is an environmental risk factor for psychotic disorder, possibly due to the experience of social exclusion. The aim of the current study is to investigate whether people with SHI exhibit higher levels of psychotic reactivity to social stressors in daily life than normal-hearing controls and whether this reactivity is associated with decreased baseline dopamine (DA) D2/3 receptor availability and/or elevated DA release following a dexamphetamine challenge.

METHOD

We conducted an experience sampling study in 15 young adults with SHI and 19 matched normal-hearing controls who had previously participated in a single photon emission computed tomography study measuring DA D2/3 receptor availability and DA release in response to dexamphetamine.

RESULTS

The association between social stress and momentary psychotic experiences in daily life was stronger among SHI participants than among normal-hearing controls. Interactions between social stress and baseline striatal DA D2/3 receptor availability or DA release were not significant in multilevel models of momentary psychotic experiences including age, sex and tobacco use.

CONCLUSIONS

While both elevated striatal DA release and elevated psychotic stress reactivity have been found in the same population defined by an environmental risk factor, SHI, their inter-relationship cannot be established. Further research is warranted to clarify the association between biological and psychological endophenotypes and psychosis risk.

Much ado about much: stress, dynamic biomarkers and HPA axis dysregulation along the trajectory to psychosis

OBJECTIVES

In the context of a stress-vulnerability framework, hyperactivation of the hypothalamic-pituitary-adrenal (HPA) axis is thought contribute to the risk, onset and course of psychotic illness. However, recent reports regarding static and dynamic features of the HPA axis suggest a more complex set of phenomena at play in the early phases of psychosis.

METHODS

We review literature regarding structural and functional aspects of the HPA axis in subjects at risk for or experiencing the first episode of psychosis, including evidence favoring as well as that which contradicts a model of HPA axis hyperactivation.

RESULTS

Static measures of diurnal cortisol and hippocampal/pituitary volumes suggest that the HPA axis is in a hyperactivated state in early phases of psychosis. In contrast, the dynamic cortisol response to encountered or anticipated stress is blunted in the same populations. These incongruent findings need to be better understood.

CONCLUSIONS

We consider potential explanations for the seemingly contradictory elevation and blunting of HPA biomarkers in the early course of psychosis. Finally, we propose and explore implications of a conceptual model of tonic HPA hyperactivation and phasic HPA blunting that integrates and reconciles these data.

Ambulatory assessment as a means of longitudinal phenotypes characterization in psychiatric disorders

Ambulatory Assessment (AA) comprises the use of in-field methods to assess individuals' behavior, physiology, and the experience as they unfold in naturalistic settings. We propose that AA is favorable for the investigation of gene-environment interactions and for the search for endophenotypes, being able to assess the experienced environment and to track basic regulatory processes, such as stress reactivity, affective instability, and reward experience, which are potential common factors that underlie psychiatric disorders. In this article, we (a) first describe briefly the rationale of AA and summarize the key advantages of the approach, (b) highlight within-subject regulatory processes, such as stress reactivity, affective instability, and reward experience, (c) describe studies that used AA to examine genetic influences in psychiatric disorders, and (d) briefly review longitudinal studies that have investigated phenotypes of psychiatric disorders. The reported studies yielded promising, although sometimes inconclusive evidence for genetic effects on endophenotypes of psychiatric disorders. Moreover, most studies were twin or family studies, especially in stress-sensitivity research; thus, it is unclear which specific single nucleotide polymorphisms contribute to the endophenotypes of psychiatric disorders. We do hope that within-subject regulatory processes will enable us to clarify the fundamental psychological dimensions that cut across traditional disorders and link them to their genetic underpinnings.

Impaired metabolic reactivity to oxidative stress in early psychosis patients

Because increasing evidence point to the convergence of environmental and genetic risk factors to drive redox dysregulation in schizophrenia, we aim to clarify whether the metabolic anomalies associated with early psychosis reflect an adaptation to oxidative stress. Metabolomic profiling was performed to characterize the response to oxidative stress in fibroblasts from control individuals (n = 20) and early psychosis patients (n = 30), and in all, 282 metabolites were identified. In addition to the expected redox/antioxidant response, oxidative stress induced a decrease of lysolipid levels in fibroblasts from healthy controls that were largely muted in fibroblasts from patients. Most notably, fibroblasts from patients showed disrupted extracellular matrix- and arginine-related metabolism after oxidative stress, indicating impairments beyond the redox system. Plasma membrane and extracellular matrix, 2 regulators of neuronal activity and plasticity, appeared as particularly susceptible to oxidative stress and thus provide novel mechanistic insights for pathophysiological understanding of early stages of psychosis. Statistically, antipsychotic medication at the time of biopsy was not accounting for these anomalies in the metabolism of patients' fibroblasts, indicating that they might be intrinsic to the disease. Although these results are preliminary and should be confirmed in a larger group of patients, they nevertheless indicate that the metabolic signature of reactivity to oxidative stress may provide reliable early markers of psychosis. Developing protective measures aimed at normalizing the disrupted pathways should prevent the pathological consequences of environmental stressors.

Developmental mechanisms in the prodrome to psychosis

Psychotic disorders continue to be among the most disabling and scientifically challenging of all mental illnesses. Accumulating research findings suggest that the etiologic processes underlying the development of these disorders are more complex than had previously been assumed. At the same time, this complexity has revealed a wider range of potential options for preventive intervention, both psychosocial and biological. In part, these opportunities result from our increased understanding of the dynamic and multifaceted nature of the neurodevelopmental mechanisms involved in the disease process, as well as the evidence that many of these entail processes that are malleable. In this article, we review the burgeoning research literature on the prodrome to psychosis, based on studies of individuals who meet clinical high risk criteria. This literature has examined a range of factors, including cognitive, genetic, psychosocial, and neurobiological. We then turn to a discussion of some contemporary models of the etiology of psychosis that emphasize the prodromal period. These models encompass the origins of vulnerability in fetal development, as well as postnatal stress, the immune response, and neuromaturational processes in adolescent brain development that appear to go awry during the prodrome to psychosis. Then, informed by these neurodevelopmental models of etiology, we turn to the application of new research paradigms that will address critical issues in future investigations. It is expected that these studies will play a major role in setting the stage for clinical trials aimed at preventive intervention.

Evidence that a psychopathology interactome has diagnostic value, predicting clinical needs: an experience sampling study

BACKGROUND

For the purpose of diagnosis, psychopathology can be represented as categories of mental disorder, symptom dimensions or symptom networks. Also, psychopathology can be assessed at different levels of temporal resolution (monthly episodes, daily fluctuating symptoms, momentary fluctuating mental states). We tested the diagnostic value, in terms of prediction of treatment needs, of the combination of symptom networks and momentary assessment level.

METHOD

Fifty-seven patients with a psychotic disorder participated in an ESM study, capturing psychotic experiences, emotions and circumstances at 10 semi-random moments in the flow of daily life over a period of 6 days. Symptoms were assessed by interview with the Positive and Negative Syndrome Scale (PANSS); treatment needs were assessed using the Camberwell Assessment of Need (CAN).

RESULTS

Psychotic symptoms assessed with the PANSS (Clinical Psychotic Symptoms) were strongly associated with psychotic experiences assessed with ESM (Momentary Psychotic Experiences). However, the degree to which Momentary Psychotic Experiences manifested as Clinical Psychotic Symptoms was determined by level of momentary negative affect (higher levels increasing probability of Momentary Psychotic Experiences manifesting as Clinical Psychotic Symptoms), momentary positive affect (higher levels decreasing probability of Clinical Psychotic Symptoms), greater persistence of Momentary Psychotic Experiences (persistence predicting increased probability of Clinical Psychotic Symptoms) and momentary environmental stress associated with events and activities (higher levels increasing probability of Clinical Psychotic Symptoms). Similarly, the degree to which momentary visual or auditory hallucinations manifested as Clinical Psychotic Symptoms was strongly contingent on the level of accompanying momentary paranoid delusional ideation. Momentary Psychotic Experiences were associated with CAN unmet treatment needs, over and above PANSS measures of psychopathology, similarly moderated by momentary interactions with emotions and context.

CONCLUSION

The results suggest that psychopathology, represented as an interactome at the momentary level of temporal resolution, is informative in diagnosing clinical needs, over and above traditional symptom measures.

Familial liability to psychosis is associated with attenuated dopamine stress signaling in ventromedial prefrontal cortex

OBJECTIVE

Patients diagnosed with a psychotic disorder and their first-degree relatives display increased reactivity to stress. Theory predicts that experience of psychosocial stress is associated both with ventromedial prefrontal and mesolimbic dopamine neurotransmission. However, while there is evidence of aberrant striatal dopamine processing in psychotic disorder, the role of the prefrontal cortex remains under-researched. This study aimed at investigating stress-induced in vivo dopamine release in ventromedial prefrontal cortex (vmPFC) of individuals at familial risk for psychosis.

METHOD

Fourteen healthy first-degree relatives of patients with a diagnosis of psychotic disorder and 10 control subjects underwent a single dynamic positron emission tomography (PET) scanning session after intravenous administration of 183.2 (SD = 7.6) MBq [(18)F]fallypride. Psychosocial stress was initiated at 100 min postinjection using a computerized mental arithmetic task with social evaluative threat components. PET data were analyzed using the linearized simplified reference region model. Regression analyses were performed to compare the spatial extent of task-related ligand displacement between control subjects and relatives and to find how it related to self-rated experiences of psychosocial stress and psychosis.

RESULTS

First-degree relatives displayed hyporeactive dopamine signaling in the vmPFC in response to stress. Increased levels of subjectively rated stress were associated with increased intensity of psychotic experiences. This effect was particularly pronounced in first-degree relatives.

CONCLUSION

Although previous studies have hypothesized a role for prefrontal dopamine dysfunction in psychosis, this study, to our knowledge, is the first in vivo human imaging study showing attenuated (ie, hyporeactive) dopamine stress neuromodulation in vmPFC of individuals at familial risk for psychosis.

An Overview of the Association between Schizotypy and Dopamine

Schizotypy refers to a constellation of personality traits that are believed to mirror the subclinical expression of schizophrenia in the general population. Evidence from pharmacological studies indicates that dopamine (DA) is involved in the etiology of schizophrenia. Based on the assumption of a continuum between schizophrenia and schizotypy, researchers have begun investigating the association between DA and schizotypy using a wide range of methods. In this article, we review published studies on this association from the following areas of work: (1) experimental investigations of the interactive effects of dopaminergic challenges and schizotypy on cognition, motor control, and behavior (2), dopaminergically supported cognitive functions (3), studies of associations between schizotypy and polymorphisms in genes involved in dopaminergic neurotransmission, and (4) molecular imaging studies of the association between schizotypy and markers of the DA system. Together, data from these lines of evidence suggest that DA is important to the expression and experience of schizotypy and associated behavioral biases. An important observation is that the experimental designs, methods, and manipulations used in this research are highly heterogeneous. Future studies are required to replicate individual observations, to enlighten the link between DA and different schizotypy dimensions (positive, negative, cognitive disorganization), and to guide the search for solid DA-sensitive behavioral markers. Such studies are important in order to clarify inconsistencies between studies. More work is also needed to identify differences between dopaminergic alterations in schizotypy compared to the dysfunctions observed in schizophrenia.

Altered transfer of momentary mental states (ATOMS) as the basic unit of psychosis liability in interaction with environment and emotions

Psychotic disorders are thought to represent altered neural function. However, research has failed to map diagnostic categories to alterations in neural networks. It is proposed that the basic unit of psychotic psychopathology is the moment-to-moment expression of subtle anomalous experiences of subclinical psychosis, and particularly its tendency to persist from moment-to-moment in daily life, under the influence of familial, environmental, emotional and cognitive factors.

In a general population twin sample (n = 579) and in a study of patients with psychotic disorder (n = 57), their non-psychotic siblings (n = 59) and unrelated controls (n = 75), the experience sampling paradigm (ESM; repetitive, random sampling of momentary mental states and context) was applied. We analysed, in a within-person prospective design, (i) transfer of momentary anomalous experience at time point (t–1) to time point (t) in daily life, and (ii) moderating effects of negative affect, positive affect, daily stressors, IQ and childhood trauma. Additionally, (iii) familial associations between persistence of momentary anomalous experience and psychotic symptomatology were investigated. Higher level of schizotypy in the twins (but not higher level of psychotic symptoms in patients) predicted more persistence of momentary anomalous experience in daily life, both within subjects and across relatives. Persistence of momentary anomalous experience was highest in patients, intermediate in their siblings and lowest in controls. In both studies, persistence of momentary anomalous experience was moderated by higher levels of negative affect, daily stressors and childhood trauma (only in twins), and by lower levels of positive affect. The study of alterations in the moment-to-moment transfer of subtle anomalous experience of psychosis, resulting in their persistence, helps to explain why psychotic and emotional dysregulation tend to cluster in a single phenotype such as schizophrenia, and how familial and environmental risks increase the risk of expression of psychosis from, first, subtle momentary anomalous experience to, second, observable clinical symptoms.

Stress abnormalities in individuals at risk for psychosis: a review of studies in subjects with familial risk or with "at risk" mental state

Increased sensitivity to stress is known to play an important role in the transition to first episode psychosis (FEP). Hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis, and, in general, an increased sensitivity to stress, have been hypothesised to be components of the vulnerability to psychosis, but whether these abnormalities are already present before the onset of psychosis has not yet been systematically reviewed. Here we have reviewed all studies examining psychological and biological markers of the stress response in the relatives of psychotic patients and in individuals at Ultra High Risk (UHR) for psychosis. In relatives, there is evidence of increased sensitivity to stress, as shown by increased emotional reactivity to daily life stress, increased adrenocorticotropic hormone (ACTH) in response to stress, increased pituitary volume and reduced hippocampal volume. However, evidence of increased cortisol levels is less consistent. On the other hand, subjects who experience attenuated psychotic symptoms show increased cortisol levels as well as increased pituitary and reduced hippocampal volumes. Moreover, this HPA axis hyperactivity seems to be even greater among those individuals who subsequently develop frank psychosis. In summary, an enhanced HPA axis response to stress appears to be part of the biological vulnerability to psychosis which is present prior to the onset of psychosis. A further increase in cortisol levels during the transition to FEP suggests the presence of an additive factor, possibly environmental, at this stage of the illness. Possible causes and consequences of HPA axis impairment in risk for psychosis are discussed.

Etiopathogenic perspectives on chronic psycho traumatic and chronic psychotic symptoms: the hypothesis of a hyperdopaminergic endophenotype of PTSD

Post traumatic stress disorder (PTSD) is a complex and heterogeneous disorder, which specific symptoms are re-experiencing, increased arousal and avoidance of stimuli associated with the trauma. PTSD has much comorbidity like depression, substance abuse, somatic complaints, repeated dissociative phenomena and transitory or chronic psychotic reactions. PTSD can manifest itself in different clinical forms: some patients present higher symptoms in one domain as compared to another, probably because of abnormalities in different neurobiological systems. Hyposerotonergic and hypernoradrenergic PTSD endophenotypes have been previously identified and the purpose of this paper is to focus on the hypothesis of a hyperdopaminergic endophenotype. The current review discusses several entities: PTSD with psychotic features with or without depression, the comorbide use of psychoactive substances that increase psychotic symptoms and traumatic brain injuries as agents of psycho traumatic and psychotic features. For all of these nosographic entities, the dopaminergic neuromodulation may play a central role. The hypothesis of a hyperdopaminergic endophenotype of PTSD opens up new research and therapeutic perspectives. Although antipsychotics are frequently used for people with PTSD further studies are needed to develop a consensus on the guidelines for treating the psychotic forms of PTSD.

Women and psychosis

BACKGROUND

There are subtle differences in the presentation of psychosis that depend on the biological sex of the person exhibiting the symptoms. Because much of the early research in the field was conducted on male animals and on men, several issues of importance to women have been relatively neglected until recently. Current research into psychotic illness is beginning to analyze results for men and women separately and greater emphasis on qualitative methods has allowed the experiences of women patients to be documented.

METHODS

The last decade of research into the many facets of psychosis in women were reviewed for this paper by introducing the relevant search terms into PubMed, PsycINFO and SOCINDEX.

RESULTS

Subtle differences are reported in several areas, with important ramifications for treatment.

CONCLUSIONS

It is important for service providers to devise treatment programs that address the different needs of the two sexes. Effective treatment of women with psychosis is especially important in that these women are often mothers, whose well being impacts on the health of the next generation.

Emotional and symptomatic reactivity to stress in individuals at ultra-high risk of developing psychosis

BACKGROUND

The stress-vulnerability model of psychosis continues to be influential. The aim of this study was to compare emotional and symptomatic responses to stress in individuals at ultra-high risk (UHR) of developing psychosis, in age- and gender-matched healthy controls, and in patients with non-affective psychosis.

METHOD

A total of 27 UHR, 27 psychotic and 27 healthy individuals completed the experience sampling method, an ambulant diary technique, where they were required to fill in self-assessment questions about their emotions, symptoms and perceived stress at semi-random times of the day for 6 days. Quesionnaire and interview assessments were also completed.

RESULTS

Multilevel regression analyses showed that individuals at UHR of developing psychosis reported greater negative emotions in response to stress than the healthy individuals. Against the initial hypotheses, the UHR individuals also experienced greater emotional reactivity to stress when compared with the patient group. No significant differences were observed between the patients and the non-clinical sample. Stress measures significantly predicted the intensity of psychotic symptoms in UHR individuals and patients, but the extent of this did not significantly differ between the groups.

CONCLUSIONS

Individuals at UHR of developing psychosis may be particularly sensitive to everyday stressors. This effect may diminish after transition to psychosis is made and in periods of stability. Subtle increases in psychotic phenomena occur in response to stressful events across the continuum of psychosis.

Increased stress-induced dopamine release in psychosis

BACKGROUND

A pathologic response to common life stressors, in which a hyperresponsive dopaminergic system is thought to play a key role, is a potential etiologic factor in the triggering and relapse of psychosis. However, there is no direct evidence that brain dopaminergic response to stress is exaggerated in psychosis.

METHODS

Using the ability of endogenous dopamine (DA) to compete with [(11)C]-(+)-PHNO binding, as measured with positron emission tomography, we examined stress-induced DA release in response to a validated psychosocial stress task. We studied 12 clinical high-risk (CHR), 10 antipsychotic-naive subjects with schizophrenia (SCZ), and 12 matched healthy volunteers (HV). Stress-induced DA release was estimated as the percent change in binding potential between conditions (stress and control scan) in the striatal subdivisions: limbic striatum (LST), associative striatum (AST), and sensorimotor striatum (SMST).

RESULTS

We found a significant difference between groups in the AST (F = 8.13, df = 2,31, p = .001), and at the SMST (F = 3,64, df = 2,31, p = .03) but not in the LST (F = .43, df = 2,31, p = .40) with CHR and SCZ having larger [(11)C]-(+)-PHNO displacement in response to the stress. Bonferroni-corrected comparisons confirmed that HV displacement (-2.86%) in the AST was significantly different in CHR (6.97%) and SCZ (11.44%) (with no significant difference between CHR and SCZ).

CONCLUSIONS

This study reveals a sensitized dopaminergic response to stress in a psychiatric condition and may have important theoretical and clinical implications regarding efforts to abort or delay relapse and/or conversion to psychosis.

Neuropsychological research in delusional disorder: a comprehensive review

In recent decades, there has been a growing interest in the field of delusions, and different aspects of delusional disorder (DD) have been investigated. However, DD is still one of the most underresearched psychiatric disorders. In this paper, we review the literature on DD and most of the theoretical approaches proposed to explain the development and maintenance of delusions. DD research is infrequent, and delusions in this disorder have been scarcely investigated. We aim to establish the state of the art of delusions research to date and point to the shortage of neuropsychological studies in patients with DD. We also justify the need for future research into the neuropsychological correlates of DD as measured in patients with this disorder given that most previous research has mainly focused on other psychotic conditions.

Daily cortisol, stress reactivity and psychotic experiences in individuals at above average genetic risk for psychosis

BACKGROUND

Hypothalamic-pituitary-adrenocortical (HPA) axis abnormalities have been found in patients with a psychotic disorder and first-degree relatives of patients with a psychotic disorder react with subtle increases in non-clinical psychotic experiences and negative emotions in the face of everyday stress. The current study investigated whether HPA axis functioning is altered in individuals at above average genetic risk for psychotic disorder, examining diurnal cortisol profiles, cortisol reactivity to daily stressors and the association between HPA axis activity and subclinical psychotic experiences.

METHOD

Participants included siblings of patients with a psychotic disorder (n=60) and a healthy comparison group (n=63). The Experience Sampling Method (a structured diary technique) was employed to assess stress, psychotic experiences, negative affect and salivary cortisol repeatedly in the flow of daily life.

RESULTS

Multi-level analyses revealed higher diurnal cortisol levels and heightened cortisol reactivity to negative daily events in siblings compared with controls. Diurnal cortisol slope did not differ between the two groups, but momentary increases in psychotic experiences and negative affect were associated with increased cortisol in the sibling group.

CONCLUSIONS

Findings support altered HPA axis activity in individuals at above average genetic risk for psychotic disorder, as evidenced by higher diurnal cortisol levels and increased cortisol reactivity to daily stress. Results also suggest a dynamic association between cortisol secretion and the intensity of psychotic-like experiences and negative emotions in daily life, although the direction of this association remains to be elucidated.

Affective dysregulation and reality distortion: a 10-year prospective study of their association and clinical relevance

Evidence from clinical patient populations indicates that affective dysregulation is strongly associated with reality distortion, suggesting that a process of misassignment of emotional salience may underlie this connection. To examine this in more detail without clinical confounds, affective regulation-reality distortion relationships, and their clinical relevance, were examined in a German prospective cohort community study. A cohort of 2524 adolescents and young adults aged 14-24 years at baseline was examined by experienced psychologists. Presence of psychotic experiences and (hypo)manic and depressive symptoms was assessed at 2 time points (3.5 and up to 10 years after baseline) using the Munich-Composite International Diagnostic Interview. Associations were tested between level of affective dysregulation on the one hand and incidence of psychotic experiences, persistence of these experiences, and psychotic Impairment on the other. Most psychotic experiences occurred in a context of affective dysregulation, and bidirectional dose-response was apparent with greater level of both affective dysregulation and psychotic experiences. Persistence of psychotic experiences was progressively more likely with greater level of (hypo)manic symptoms (odds ratio [OR] trend=1.51, P<.001) and depressive symptoms (OR trend=1.15, P=.012). Similarly, psychotic experiences of clinical relevance were progressively more likely to occur with greater level of affective dysregulation (depressive symptoms: OR trend=1.28, P=.002; (hypo)manic symptoms: OR trend=1.37, P=.036). Correlated genetic liabilities underlying affective and nonaffective psychotic syndromes may be expressed as correlated dimensions in the general population. Also, affective dysregulation may contribute causally to the persistence and clinical relevance of reality distortion, possibly by facilitating a mechanism of aberrant salience attribution.

Childhood trauma and increased stress sensitivity in psychosis

OBJECTIVE

The notion that traumatic experiences in childhood may predict later psychotic outcomes would be strengthened if a plausible mechanism could be demonstrated. Because increased stress sensitivity is part of the behavioural expression of psychosis liability, the possible mediating role of childhood trauma was investigated.

METHOD

Fifty patients with psychosis were studied with the experience sampling method to assess stress reactivity in daily life, defined as emotional and psychotic reactivity to stress. Traumatic experiences in childhood were assessed with the Childhood Trauma Questionnaire.

RESULTS

A significant interaction was found between stress and CT on both negative affect (event stress: β = 0.04, P < 0.04; activity stress: β = 0.12, P < 0.001) and psychotic intensity (event stress: β = 0.06, P < 0.001; activity stress: β = 0.11, P < 0.001), showing that a history of CT is associated with increased sensitivity to stress.

CONCLUSION

A history of childhood trauma in patients with psychosis is associated with increased stress reactivity later in life, suggestive for an underlying process of behavioural sensitization.

Psychosis reactivity to cannabis use in daily life: an experience sampling study

BACKGROUND

Little is known about the experiential dynamics of the interaction between cannabis and vulnerability to psychosis.

AIMS

To examine the effects of cannabis on psychotic symptoms and mood in patients with psychosis and healthy controls.

METHOD

Patients with a psychotic disorder (n = 42) and healthy controls (n = 38) were followed in their daily lives using a structured time-sampling technique.

RESULTS

Daily life cannabis use predicted subsequent increases in positive affect and in patients, but not in controls, decreases in negative affect. In patients, but not in controls, cannabis use predicted increased levels of hallucinatory experiences. Mood-enhancing properties of cannabis were acute, whereas psychosis-inducing effects were sub-acute. There was no direct evidence for self-medication effects in daily life.

CONCLUSIONS

Patients with psychosis are more sensitive to both the psychosis-inducing and mood-enhancing effects of cannabis. The temporal dissociation between acute rewarding effects and sub-acute toxic influences may be instrumental in explaining the vicious circle of deleterious use in these patients.