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

Simulation-Based Performance Evaluation of Missing Data Handling in Network Analysis

Network analysis has gained popularity as an approach to investigate psychological constructs. However, there are currently no guidelines for applied researchers when encountering missing values. In this simulation study, we compared the performance of a two-step EM algorithm with separated steps for missing handling and regularization, a combined direct EM algorithm, and pairwise deletion. We investigated conditions with varying network sizes, numbers of observations, missing data mechanisms, and percentages of missing values. These approaches are evaluated with regard to recovering population networks in terms of loss in the precision matrix, edge set identification and network statistics. The simulation showed adequate performance only in conditions with large samples (n ≥ 500 ) or small networks (p = 10). Comparing the missing data approaches, the direct EM appears to be more sensitive and superior in nearly all chosen conditions. The two-step EM yields better results when the ratio of n/p is very large - being less sensitive but more specific. Pairwise deletion failed to converge across numerous conditions and yielded inferior results overall. Overall, direct EM is recommended in most cases, as it is able to mitigate the impact of missing data quite well, while modifications to two-step EM could improve its performance.

Response to psychotic experiences: Impact of personality traits on perceived levels of distress

BACKGROUND

This study examined the influence of personality traits on (subclinical) positive symptom distress in patients with a psychotic disorder, their unaffected siblings and healthy controls.

METHODS

Data were obtained from the Genetic Risk and Outcome of Psychosis study (GROUP), a Dutch longitudinal multicenter cohort study. Data from 140 patients, 216 unaffected siblings and 102 healthy controls was available for baseline levels of Five Factor Model personality traits and frequency and distress due to psychotic experiences three years later, assessed with the Community Assessment of Psychic Experience questionnaire. Main effects of all five personality traits on symptom distress were investigated as well as moderating effects of Neuroticism, Extraversion and Openness on positive symptom frequency and positive symptom distress. Age, gender, symptom frequency and IQ were controlled for.

RESULTS

In both patients and siblings, the observed main effects of Neuroticism and Openness on (subclinical) positive symptom distress three years later either lost significance or had a very small effect size when controlling for covariates, mainly due to the correction for the effect of positive symptoms on personality traits at baseline. In both groups, levels of Openness at baseline moderated the association between positive symptom frequency and positive symptom distress three years later, in the direction that higher levels of Openness were associated with weaker associations between positive symptom frequency and - distress, even when covariates were controlled for.

DISCUSSION

The level of Openness to Experiences influences the perceived distress from (subclinical) positive symptoms in both patients and siblings.

Sexual abuse and psychotic phenomena: a directed acyclic graph analysis of affective symptoms using English national psychiatric survey data

BACKGROUND

Sexual abuse and bullying are associated with poor mental health in adulthood. We previously established a clear relationship between bullying and symptoms of psychosis. Similarly, we would expect sexual abuse to be linked to the emergence of psychotic symptoms, through effects on negative affect.

METHOD

We analysed English data from the Adult Psychiatric Morbidity Surveys, carried out in 2007 (N = 5954) and 2014 (N = 5946), based on representative national samples living in private households. We used probabilistic graphical models represented by directed acyclic graphs (DAGs). We obtained measures of persecutory ideation and auditory hallucinosis from the Psychosis Screening Questionnaire, and identified affective symptoms using the Clinical Interview Schedule. We included cannabis consumption and sex as they may determine the relationship between symptoms. We constrained incoming edges to sexual abuse and bullying to respect temporality.

RESULTS

In the DAG analyses, contrary to our expectations, paranoia appeared early in the cascade of relationships, close to the abuse variables, and generally lying upstream of affective symptoms. Paranoia was consistently directly antecedent to hallucinations, but also indirectly so, via non-psychotic symptoms. Hallucinosis was also the endpoint of pathways involving non-psychotic symptoms.

CONCLUSIONS

Via worry, sexual abuse and bullying appear to drive a range of affective symptoms, and in some people, these may encourage the emergence of hallucinations. The link between adverse experiences and paranoia is much more direct. These findings have implications for managing distressing outcomes. In particular, worry may be a salient target for intervention in psychosis.

Hasty decision making and belief inflexibility in the more delusion prone? A modified disambiguating-scenarios paradigm assessing cognitive biases implicated in delusions

INTRODUCTION

Contemporary models of psychosis imply that cognitive biases such as the jumping to conclusions (JTC), the bias against disconfirmatory evidence (BADE), and the liberal acceptance (LA) bias play a role in the pathogenesis of delusions. Most of the studies investigating the role of cognitive biases, however, have been conducted with socially neutral or abstract stimuli and have assessed patients with established psychoses. For the present study, we aimed to concurrently investigate multiple biases (i.e., the JTC, BADE, and LA biases) in a community sample with a new paradigm using more socially engaging stimuli.

METHODS

A large sample of participants (N = 874) recruited via Amazon Mechanical Turk was subdivided into two groups based on the frequency of their psychotic-like experiences (PLEs) according to the positive subscale score of the Community Assessment of Psychic Experiences (CAPE) and matched based on major demographics variables, resulting in two equally sized groups called High-PLE (at least 2 SD above the mean) and Low-PLE (maximum 0.5 above the mean; n = 46 for each group). Using a modified version of the written-scenarios BADE task, which emphasized social interactions between agents embedded in the scenario, participants rated the plausibility of response options in the face of new information.

RESULTS

In line with previous findings, the High-PLE group demonstrated the JTC, BADE, and LA biases. That is, the members of this group made more decisions after the initial piece of information, were less likely to revise their beliefs in light of new information, and provided higher plausibility ratings for implausible response options compared to the Low-PLE group.

CONCLUSIONS

Results corroborate prior findings suggesting that the JTC, BADE, and LA biases may be contributing factors in delusional ideation and that metacognitive biases extend to social situations.

Disentangling heterogeneity of psychosis expression in the general population: sex-specific moderation effects of environmental risk factors on symptom networks

BACKGROUND

Psychosis expression in the general population may reflect a behavioral manifestation of the risk for psychotic disorder. It can be conceptualized as an interconnected system of psychotic and affective experiences; a so-called 'symptom network'. Differences in demographics, as well as exposure to adversities and risk factors, may produce substantial heterogeneity in symptom networks, highlighting potential etiological divergence in psychosis risk.

METHODS

To explore this idea in a data-driven way, we employed a novel recursive partitioning approach in the 2007 English National Survey of Psychiatric Morbidity (N = 7242). We sought to identify 'network phenotypes' by explaining heterogeneity in symptom networks through potential moderators, including age, sex, ethnicity, deprivation, childhood abuse, separation from parents, bullying, domestic violence, cannabis use, and alcohol.

RESULTS

Sex was the primary source of heterogeneity in symptom networks. Additional heterogeneity was explained by interpersonal trauma (childhood abuse and domestic violence) in women and domestic violence, cannabis use, ethnicity in men. Among women, especially those exposed to early interpersonal trauma, an affective loading within psychosis may have distinct relevance. Men, particularly those from minority ethnic groups, demonstrated a strong network connection between hallucinatory experiences and persecutory ideation.

CONCLUSION

Symptom networks of psychosis expression in the general population are highly heterogeneous. The structure of symptom networks seems to reflect distinct sex-related adversities, etiologies, and mechanisms of symptom-expression. Disentangling the complex interplay of sex, minority ethnic group status, and other risk factors may help optimize early intervention and prevention strategies in psychosis.

Dynamic networks of psychotic symptoms in adults living in precarious housing or homelessness

BACKGROUND

People living in precarious housing or homelessness have higher than expected rates of psychotic disorders, persistent psychotic symptoms, and premature mortality. Psychotic symptoms can be modeled as a complex dynamic system, allowing assessment of roles for risk factors in symptom development, persistence, and contribution to premature mortality.

METHOD

The severity of delusions, conceptual disorganization, hallucinations, suspiciousness, and unusual thought content was rated monthly over 5 years in a community sample of precariously housed/homeless adults (n = 375) in Vancouver, Canada. Multilevel vector auto-regression analysis was used to construct temporal, contemporaneous, and between-person symptom networks. Network measures were compared between participants with (n = 219) or without (n = 156) history of psychotic disorder using bootstrap and permutation analyses. Relationships between network connectivity and risk factors including homelessness, trauma, and substance dependence were estimated by multiple linear regression. The contribution of network measures to premature mortality was estimated by Cox proportional hazard models.

RESULTS

Delusions and unusual thought content were central symptoms in the multilevel network. Each psychotic symptom was positively reinforcing over time, an effect most pronounced in participants with a history of psychotic disorder. Global connectivity was similar between those with and without such a history. Greater connectivity between symptoms was associated with methamphetamine dependence and past trauma exposure. Auto-regressive connectivity was associated with premature mortality in participants under age 55.

CONCLUSIONS

Past and current experiences contribute to the severity and dynamic relationships between psychotic symptoms. Interrupting the self-perpetuating severity of psychotic symptoms in a vulnerable group of people could contribute to reducing premature mortality.

Longitudinal symptom network structure in first-episode psychosis: a possible marker for remission

BACKGROUND

Network approach has been applied to a wide variety of psychiatric disorders. The aim of the present study was to identify network structures of remitters and non-remitters in patients with first-episode psychosis (FEP) at baseline and the 6-month follow-up.

METHODS

Participants (n = 252) from the Korean Early Psychosis Study (KEPS) were enrolled. They were classified as remitters or non-remitters using Andreasen's criteria. We estimated network structure with 10 symptoms (three symptoms from the Positive and Negative Syndrome Scale, one depressive symptom, and six symptoms related to schema and rumination) as nodes using a Gaussian graphical model. Global and local network metrics were compared within and between the networks over time.

RESULTS

Global network metrics did not differ between the remitters and non-remitters at baseline or 6 months. However, the network structure and nodal strengths associated with positive-self and positive-others scores changed significantly in the remitters over time. Unique central symptoms for remitters and non-remitters were cognitive brooding and negative-self, respectively. The correlation stability coefficients for nodal strength were within the acceptable range.

CONCLUSION

Our findings indicate that network structure and some nodal strengths were more flexible in remitters. Negative-self could be an important target for therapeutic intervention.

Comparing psychotic experiences in low-and-middle-income-countries and high-income-countries with a focus on measurement invariance

BACKGROUND

The prevalence of psychotic experiences (PEs) is higher in low-and-middle-income-countries (LAMIC) than in high-income countries (HIC). Here, we examine whether this effect is explicable by measurement bias.

METHODS

A community sample from 13 countries (N = 7141) was used to examine the measurement invariance (MI) of a frequently used self-report measure of PEs, the Community Assessment of Psychic Experiences (CAPE), in LAMIC (n = 2472) and HIC (n = 4669). The CAPE measures positive (e.g. hallucinations), negative (e.g. avolition) and depressive symptoms. MI analyses were conducted with multiple-group confirmatory factor analyses.

RESULTS

MI analyses showed similarities in the structure and understanding of the CAPE factors between LAMIC and HIC. Partial scalar invariance was found, allowing for latent score comparisons. Residual invariance was not found, indicating that sum score comparisons are biased. A comparison of latent scores before and after MI adjustment showed both overestimation (e.g. avolition, d = 0.03 into d = -0.42) and underestimation (e.g. magical thinking, d = -0.03 into d = 0.33) of PE in LAMIC relative to HIC. After adjusting the CAPE for MI, participants from LAMIC reported significantly higher levels on most CAPE factors but a significantly lower level of avolition.

CONCLUSION

Previous studies using sum scores to compare differences across countries are likely to be biased. The direction of the bias involves both over- and underestimation of PEs in LAMIC compared to HIC. Nevertheless, the study confirms the basic finding that PEs are more frequent in LAMIC than in HIC.

Impact of conspiracist ideation and psychotic-like experiences in patients with schizophrenia during the COVID-19 crisis

Conspiratorial belief is a type of argument that accepts implausible explanations in situations of great uncertainty or mystery. Claiming that the coronavirus is an artificial fabrication of laboratories is an example of conspiracist belief. The aim of this research was to analyze the impact of conspiracist ideation and psychotic-like experiences in patients with schizophrenia, patients with other mental disorders, and participants with no psychiatric history with a 132-day follow-up during the COVID-19 crisis. Analysis of variance (ANOVA) was applied and Bayesian inferences were carried out. The results conclude that conspiracist ideation and psychotic-like experiences increased significantly after 132 days of social-health restrictions in the general population. However, psychotic-like experiences did not increase in patients with schizophrenia. Conspiracist ideation has a quantitative degradation similar to the continuum model of psychosis; it is present both in patients with schizophrenia and in those participants with no clinical history. The psychopathological value of conspiracist ideation within the spectrum of psychosis is discussed.

Insight-related beliefs and controllability appraisals contribute little to hallucinated voices: a transdiagnostic network analysis study

Hallucinated voices cause high levels of distress and disability. Current theories suggest that insight-related beliefs, about internal or external origin, perceived source location, and appraisals of controllability are important in mediating the impact of these experiences but previous findings have been mixed. We report two open code and open data network analytic studies of items in the Psychotic Symptoms Ratings Scale for auditory verbal hallucinations (PSYRATS-AH) in a large sample of patients with hallucinated voices to examine the network structure of items at (1) first assessment, and (2) differences over two consecutive assessments during a wait-list period. Networks were generated using least absolute shrinkage and selection operator (LASSO) and extended Bayesian information criterion (EBIC) with node predictability. In Study 1 (N = 386), we report that insight-related items made a negligible contribution to hallucinated voices and the controllability appraisal made at most a modest contribution. Items relating to distress and negative content were the most central and most predicted by the wider network. In Study 2 (N = 204), we tested the longitudinal stability of the structure of hallucinated voices over a period of several months, finding a small change in total hallucination score and global strength but no clear evidence for an alteration in the structural relationship. The insight-related and controllability items remained as least influential over time. Insight-related beliefs and controllability appraisals may contribute less than previously thought to distressing hallucinated voices although we do not discount that other appraisals may remain important.

Network analysis of trauma in patients with early-stage psychosis

Childhood trauma (ChT) is a risk factor for psychosis. Negative lifestyle factors such as rumination, negative schemas, and poor diet and exercise are common in psychosis. The present study aimed to perform a network analysis of interactions between ChT and negative lifestyle in patients and controls. We used data of patients with early-stage psychosis (n = 500) and healthy controls (n = 202). Networks were constructed using 12 nodes from five scales: the Brief Core Schema Scale (BCSS), Brooding Scale (BS), Dietary Habits Questionnaire, Physical Activity Rating, and Early Trauma Inventory Self Report-Short Form (ETI). Graph metrics were calculated. The nodes with the highest predictability and expected influence in both patients and controls were cognitive and emotional components of the BS and emotional abuse of the ETI. The emotional abuse was a mediator in the shortest pathway connecting the ETI and negative lifestyle for both groups. The negative others and negative self of the BCSS mediated emotional abuse to other BCSS or BS for patients and controls, respectively. Our findings suggest that rumination and emotional abuse were central symptoms in both groups and that negative others and negative self played important mediating roles for patients and controls, respectively.

Trial Registration: ClinicalTrials.gov identifier: CUH201411002.

Network structure of psychotic-like experiences in adolescents: Links with risk and protective factors

AIM

The main goal was to analyse the network structure of psychotic-like experiences (PLEs) in a large sample of adolescents. In addition, the network structure between PLEs and putative risk (mental health difficulties, suicidal behaviour, depression symptoms) and protective factors (prosocial behaviour, subjective well-being, self-esteem) for psychosis was analysed.

METHODS

The sample compromised a total of 1790 adolescents (M=15.7 years; SD=1.26), 816 men (45.6%), selected by stratified random cluster sampling. Various tools were used to measure PLEs, general psychopathology, suicide ideation and behaviour, depression symptoms, prosocial behaviour, subjective well-being, and self-esteem. The Gaussian graphical model for continuous variables and Ising model for binary variables were used for network estimation.

RESULTS

The PLEs estimated network was strongly interconnected. Unusual perceptual experiences were among the most central nodes. The average predictability of this network was 16.41%. The PLEs and risk and protective factors estimated network showed a high degree of interconnectedness between PLEs and psychopathology domains. PLEs, behavioural problems, and emotional symptoms were among the most central nodes. The mean predictability of this network was 43.46%. The results of the stability and accuracy analysis indicated that networks were accurately estimated.

CONCLUSIONS

At population level, extended psychosis phenotype can be conceptualized as a network of interacting cognitive, emotional, and behavioural features. The network model allows us to understand psychosis risk, at the same time opening new lines of study in the mental health arena.

The network structure of schizotypy in the general population

Schizotypal personality traits show similarity with schizophrenia at various levels of analysis. It is generally agreed that schizotypal personality is multidimensional; however, it is still debated whether impulsive nonconformity should be incorporated into theories and measurement of schizotypy. In addition, relatively little is known about the network structure of the four-dimensional model of schizotypal personality. To estimate the network structure of schizotypy, we used data from participants recruited from the community (N = 11,807) who completed the short version of the Oxford-Liverpool Inventory of Feelings and Experiences, a widespread self-report instrument that assesses the positive, negative, disorganised and impulsive domains of schizotypy. We performed community detection, then examined differences between communities in terms of centralities and compared the strength of edges within and between communities. We found communities that almost perfectly corresponded to the a priori-defined subscales (93% overlap, normalised mutual information = 0.74). Items in the disorganisation community had higher closeness centrality relative to items in the other communities (Cliff's Δs ranged from 0.55 to 0.83) and weights of edges within the disorganisation community were stronger as compared to the negative schizotypy and impulsive nonconformity communities (Cliff's Δs = 0.33). Our findings imply that the inclusion of impulsive nonconformity items does not dilute the classical three-factor structure of positive, negative and disorganised schizotypy. The high closeness centrality of disorganisation concurs with theories positing that cognitive slippage and associative loosening are core features of the schizophrenic phenotype.

The Role of Emotional Regulation in Anxiety and Depression Symptom Interplay and Expression among Adolescent Females

Depression and anxiety are highly comorbid constructs. However little is known about the mechanisms that underpin this comorbidity/connectivity or the divergence between constructs that seems to occur in adolescence. The current study targeted emotion regulation (ER) as a potential plausible mechanism for explaining how anxiety and depression symptoms in adolescence might begin to connect, perpetuate, and ultimately diverge from one another. Using data from a cross-sectional school-based study, of adolescent females (age 11–18 years; N = 615; majority were white (97.7%)), we modelled variation in ER using latent profile analysis. Then, using network analysis (NA), we generated separate depression-anxiety symptom networks for adolescents at varying levels of ER. Three latent classes of ER were identified (low ER 15%, intermediate ER 34%, high ER 51%). The results of the network comparison test found no significant differences in global strength between the ‘low ER’ and the ‘intermediate ER’ ability network. This study is among the first to attempt to model change in depression-anxiety symptom connectivity in adolescence in relation to a common contextual/risk factor. The current study therefore offers a unique contribution to the examination of the role of transdiagnostic factors in the study of adolescent depression and anxiety from a network perspective, and provides a promising framework for the study of ER among anxiety and depression symptomatology in adolescence.

Network Structure of Callous-Unemotional Traits and Conduct Disorder Symptoms Among At-Risk Youth: Multi-Informant Reports and Gender Differences

Network analytic techniques examine how items used to measure underlying constructs are related to one another and identify core characteristics. While many studies have examined the covariance of callous-unemotional (CU) traits or features and conduct disorder (CD) symptoms, the inter-item relations of these constructs and the core characteristics of the CU construct are unclear. The present study aimed to examine the network connectivity of, and between, CU features and CD symptoms. We also examined both parent-reports and youth self-reports and gender differences. CU features and CD symptoms were rated by parents (n = 814; 74% mothers; age 23-73, M age = 43.86, SD = 8.13) and their child (n = 608; 57% female; age 7-19, M age = 13.98, SD = 2.36). Network plots depicted greater connectivity (i.e., density and weights) for CU features relative to CD symptoms across both informants. However, youth-reported CU features and CD symptoms were less densely connected than parent-reports. Items commonly comprising the callousness subscale were more central and linked the two constructs together, relative to uncaring items, across informant and gender. Gender related effects indicated lower centrality for male versus female youth, and this finding was particularly evident in youth-reports. Our findings highlight relations between CU features and CD symptoms, and point to the importance of callousness items in conceptualizations of CU features among high-risk youth from both the perspective of the parent and child. We also inform understanding of gender differences in CU features for which the literature is currently limited.

Network study of responses to unusualness and psychological stress during the COVID-19 outbreak in Korea

The dramatic changes in people's daily lives caused by the 2019 coronavirus (COVID-19) pandemic have had a huge impact on their emotions and behaviors. This study aimed to examine psychosocial responses to COVID-19 using network analysis. A total of 1,500 urban residents of South Korea, selected from an online public panel, were surveyed using self-rating questionnaires addressing daily life changes, fear of infection, and distress related to COVID-19. Participants also completed a 10-item Perceived Stress Scale survey. We constructed regularized partial correlation networks, estimated global and local network metrics, tested network accuracy and stability, and compared the estimated networks between men and women. The network of the psychosocial responses consisted of 24 nodes that were classified into five groups: 'fear of infection', 'difficulty with outside activities', 'economic loss', 'altered eating and sleeping', and 'adaptive stress'. The node centralities indicated that 'distress in obtaining daily necessities' and 'concern about harming others' were the most important issues in people's responses to COVID-19. These nodes were connected by a negative edge, reflecting individual- and community-level issues, respectively. The overall level of perceived stress was linked to the network by the connection node 'anger toward others or society', which was associated with economic problems in men, but with distress from changes in daily activities in women. The results suggest that two contrasting feelings-personal insecurity regarding basic needs and a collectivistic orientation-play roles in the response to unusual experiences and distress due to COVID-19. This study also showed that public anger could arise from the psychological stress under the conditions imposed by COVID-19.

Network Structures of Social Functioning Domains in Schizophrenia and Bipolar Disorder: A Preliminary Study

OBJECTIVE

: This study used network analyses to examine network structures reflecting interactions between specific domains of social functioning in schizophrenia (SZ) and bipolar disorder (BD).

METHODS

We used the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) to assess six domains of social functioning ('cognition', 'mobility', 'self-care', 'getting along', 'life activities', and 'participation') in 143 patients with SZ, 81 patients with BD, and 106 healthy subjects. We constructed regularized partial correlation networks, estimated network centrality and edge strength, tested network stability, and compared SZ and BD network structures.

RESULTS

Patients with SZ showed a significantly higher level of functional disability than patients with BD. In the networks we constructed, 'cognition' was the most central domain of social functioning in both SZ and BD. The 'cognition' domain was primarily associated with the 'getting along' domain in the SZ network and the 'life activities' domain in the BD network. We found no significant group-level differences in network structures for SZ vs. BD.

CONCLUSION

Our results suggest that cognition may play a pivotal role in social functioning in both SZ and BD. In addition, domains of social functioning in SZ and BD have similar network structures despite the higher level of disability in SZ compared to BD.

Toward a Complex Network of Risks for Psychosis: Combining Trauma, Cognitive Biases, Depression, and Psychotic-like Experiences on a Large Sample of Young Adults

Although the linkage between traumatic life events and psychotic-like experiences (PLEs) is well established, the knowledge of potential mechanisms of this relationship is scarce. The aim of the present study was to better understand the structure of connections between traumatic life events and PLEs by considering at the same time the role of cognitive biases and depressive symptoms in the population of young adults (18-35 years of age, M = 26.52, SD = 4.74, n = 6772). Our study was conducted within a framework of network analysis. PLEs were measured with the Prodromal Questionnaire (PQ-16), cognitive biases were measured with nine items from the Davos Assessment of Cognitive Biases Scale-18 (DACOBS-18), depressive symptoms were assessed with the Center for Epidemiologic Studies-Depression Scale (CESD-R) and exposure to traumatic life events was measured with a combination of Childhood Experience of Care and Abuse Questionnaire (CECA.Q) and Traumatic Experience Checklist (TEC). The results present a network of all nodes being interconnected within and between domains, with no isolated factors. Exposures to sexual trauma were the most central node in the network. Pathways were identified from trauma to PLEs via cognitive biases and depressive symptoms. However, the shortest pathway between the most central traumatic life event and PLEs was through other traumatic life events, without cognitive biases or depressive symptoms along the way. Our findings suggest the importance of environmental adversities as well as dysfunctional information processing and depression in the network of psychosis risks.

Terminology and assessment tools of psychosis: A systematic narrative review

AIM

Phenomena within the psychosis continuum that varies in frequency/duration/intensity have been increasingly identified. Different terms describe these phenomena, however there is no standardization within the terminology. This review evaluated the definitions and assessment tools of seven terms - (i) 'psychotic experiences'; (ii) 'psychotic-like experiences'; (iii) 'psychotic-like symptoms'; (iv) 'attenuated psychotic symptoms'; (v) 'prodromal psychotic symptoms'; (vi) 'psychotic symptomatology'; and (vii) 'psychotic symptoms'.

METHODS

EMBASE, MEDLINE, and CINAHL were searched during February-March 2019. Inclusion criteria included 1989-2019, full text, human, and English. Papers with no explicit definition or assessment tool, duplicates, conference abstracts, systematic reviews, meta-analyses, or no access were excluded.

RESULTS

A total of 2238 papers were identified and of these, 627 were included. Definitions and assessment tools varied, but some trends were found. Psychotic experiences and psychotic-like experiences were transient and mild, found in the general population and those at-risk. Psychotic-like symptoms were subthreshold and among at-risk populations and non-psychotic mental disorders. Attenuated psychotic symptoms were subthreshold but associated with distress, risk, and help-seeking. Prodromal psychotic symptoms referred to the prodrome of psychotic disorders. Psychotic symptomatology included delusions and hallucinations within psychotic disorders. Psychotic symptoms was the broadest term, encompassing a range of populations but most commonly involving hallucinations, delusions, thought disorder, and disorganization.

DISCUSSION

A model for conceptualizing the required terms is proposed and future directions needed to advance this field of research are discussed.

The network structure of schizotypal personality traits in a population-based sample

Outcomes for people with schizophrenia-spectrum disorders (SSDs) are generally poor, making it important to understand risk states and illness transition. The network approach, which conceptualizes psychopathology as a network of causally interacting symptoms, may hold promise in this regard. Here, we present a network analysis of schizotypal personality traits (i.e., schizophrenia-like cognitive, perceptual, affective, interpersonal, and behavioral anomalies that may index one's vulnerability for a SSD) using an international sample. We analyzed data from 9505 participants between the ages of 14-70 who completed the Schizotypal Personality Questionnaire-Brief on TestMyBrain.org. In line with other research, we find that the network of schizotypal traits is densely connected, characterized by three communities of items-interpersonal (I), disorganized (D), cognitive-perceptual (CP)-with I and D features exhibiting the greatest centrality (z-scored M strength: I = 0.56, D = 0.29, CP = -0.84; expected influence: I = 0.54, D = 0.33, CP = -0.84) and predictability (M I = 0.37, D = 0.43, CP = 0.23). Importantly, within our sample, we found the estimated network to be replicable (Network Comparison Test: network structure difference: M = 0.304, p = .420; global strength difference: S = 0.904, p = .530), and estimates of node centrality to be stable (correlation-stability coefficient = 0.75). Further, we find network differences between certain groups differing in levels of SSD risk as a function of age (network structure: difference M = 0.562, p < .001; global strength difference: S = 3.483, p = .012) and ethnic minority status (global strength difference: S = 11.488, p = .004). Together, these findings demonstrate the utility of using network approaches to understand SSD risk states as well as the replicability of network findings on schizotypal personality traits and related SSD risk concepts.

Beyond Clinical High-Risk State for Psychosis: The Network Structure of Multidimensional Psychosis Liability in Adolescents

OBJECTIVES

The main goal of the present study was to analyze the network structure of schizotypy dimensions in a representative sample of adolescents from the general population. Moreover, the network structure between schizotypy, mental health difficulties, subjective well-being, bipolar-like experiences, suicide ideation and behavior, psychotic-like experiences, positive and negative affect, prosocial behavior, and IQ was analyzed.

METHOD

The study was conducted in a sample of 1,506 students selected by stratified random cluster sampling. The Oviedo Schizotypy Assessment Questionnaire, the Personal Wellbeing Index-School Children, the Paykel Suicide Scale, the Mood Disorder Questionnaire, the Strengths and Difficulties Questionnaire, the Prodromal Questionnaire-Brief, the Positive and Negative Affect Schedule for Children Shortened Version, and the Matrix Reasoning Test were used.

RESULTS

The estimated schizotypy network was interconnected. The most central nodes in terms of standardized Expected Influence (EI) were 'unusual perceptual experiences' and 'paranoid ideation'. Predictability ranged from 8.7% ('physical anhedonia') to 52.7% ('unusual perceptual experiences'). The average predictability was 36.27%, implying that substantial variability remained unexplained. For the multidimensional psychosis liability network predictability values ranged from 9% (estimated IQ) to 74.90% ('psychotic-like experiences'). The average predictability was 43.46%. The results of the stability and accuracy analysis indicated that all networks were accurately estimated.

CONCLUSIONS

The present paper points to the value of conceptualizing psychosis liability as a dynamic complex system of interacting cognitive, emotional, behavioral, and affective characteristics. In addition, provide new insights into the nature of the relationships between schizotypy, as index of psychosis liability, and the role played by risk and protective factors.

Psychotic Experiences and Related Distress: A Cross-national Comparison and Network Analysis Based on 7141 Participants From 13 Countries

Psychotic experiences (PEs) are common in the general population but do not necessarily reflect a risk status if they occur in relative isolation or are not distressing. Emerging evidence suggests that PEs might be experienced as more benign for individuals from collectivistic low- and middle-income countries (LAMIC) compared with individualistic high-income countries (HIC). The aim of this study was to determine whether: (1) self-reported PEs are less distressing in community samples from LAMIC than from HIC; (2) the network of PEs is significantly less connected in a sample from LAMIC than from HIC. Adults from 8 HIC (n = 4669) and 5 LAMIC (n = 2472) were compared. The lifetime frequency of PEs and related distress were assessed with the Community Assessment of Psychic Experiences. We analyzed the associations of PEs with distress and country type. The interconnection of PEs was visualized by a network analysis and tested for differences in global connection strengths. The average endorsement rates of PEs were significantly higher in LAMIC than in HIC (χ2 = 1772.87, P < .01, Φcramer = 0.50). There was a universal positive correlation between higher frequency of PEs and more distress, but the distress levels controlled for frequency were significantly higher in HIC (R2 = 0.11; b = 0.26; SE = 0.01; T = 17.68; P < .001). Moreover, the network of PEs was significantly less connected in LAMIC (S = 0.40, P < .05). The findings indicate that PEs are of less clinical relevance in LAMIC compared with HIC. The universal use of current high-risk criteria might thus not be adequate without consideration of associated distress and cultural values.

The Network Structure of Schizotypal Personality Traits

Elucidating schizotypal traits is important if we are to understand the various manifestations of psychosis spectrum liability and to reliably identify individuals at high risk for psychosis. The present study examined the network structures of (1) 9 schizotypal personality domains and (2) 74 individual schizotypal items, and (3) explored whether networks differed across gender and culture (North America vs China). The study was conducted in a sample of 27001 participants from 12 countries and 21 sites (M age = 22.12; SD = 6.28; 37.5% males). The Schizotypal Personality Questionnaire (SPQ) was used to assess 74 self-report items aggregated in 9 domains. We used network models to estimate conditional dependence relations among variables. In the domain-level network, schizotypal traits were strongly interconnected. Predictability (explained variance of each node) ranged from 31% (odd/magical beliefs) to 55% (constricted affect), with a mean of 43.7%. In the item-level network, variables showed relations both within and across domains, although within-domain associations were generally stronger. The average predictability of SPQ items was 27.8%. The network structures of men and women were similar (r = .74), node centrality was similar across networks (r = .90), as was connectivity (195.59 and 199.70, respectively). North American and Chinese participants networks showed lower similarity in terms of structure (r = 0.44), node centrality (r = 0.56), and connectivity (180.35 and 153.97, respectively). In sum, the present article points to the value of conceptualizing schizotypal personality as a complex system of interacting cognitive, emotional, and affective characteristics.