Terminology and assessment tools of psychosis: A systematic narrative review

Evaluation of a brief online multi-index assessment for predicting increased psychotic-like experiences in the community: A perceptual, cognitive and affective approach

Research has shown that impairments in perception, reasoning, and social cognition are evident across the psychosis continuum and are implicated in the transition from subclinical symptoms to clinical psychosis. In this pilot feasibility study, a brief computerised assessment of visual perception, reasoning, social cognition and emotion dysregulation was administered to 157 adults in the community alongside self-report measures of psychotic-like experiences. The feasibility, reliability, and the predictive validity of the assessment tool were examined. The assessment procedure was feasible, evidenced through high completion rates. However, reliability estimates were suboptimal for online assessment measures. Self-reported visual perception and state emotion dysregulation predicted psychotic-like experiences explaining 53% of the variance when controlling for age. This study provides preliminary evidence that state difficulties with emotion regulation and self-reported visual perception abnormalities can predict increased psychotic-like experiences in the community. Future adaptations could address technological issues encountered with assessment tasks and ensure measures are psychometrically robust when administered online. Brief online assessments hold potential for research of both cognition and affect along the psychosis continuum although caution must be exercised with the chosen methodology.

Cognitive functioning in people with psychotic experiences: a systematic review and meta-analysis study

Earlier research suggested that psychotic experiences (PEs), the extended-psychosis phenotype, are associated with cognitive impairment. Recent studies, however, revealed more mixed findings, and patterns and magnitude of cognitive deficits in PEs remain uncertain. We aimed to systematically review and quantitatively synthesize estimates of cognitive functioning covering a wide array of domains in individuals with versus without PEs. We systematically searched four databases from inception to 6 July 2023. We generated pooled effect size (Hedges'g) using random-effects models. Subgroup analyses and meta-regression examining the moderating effect of sex, age at PE assessment, study design, cognitive task, and PE assessment instrument on cognitive functioning were performed when applicable. The study was registered with PROSPERO (CRD42023442528). Twenty-seven and six studies were included for meta-analysis of cognitive functioning comparing individuals with versus without PEs (n = 82,561; 10,251 individuals with PEs) and individuals with high-level versus low-level PEs (n = 8062; 813 individuals with high-level PEs), respectively. Individuals with PEs exhibited worse cognitive performance in general cognition (Hedges'g = -0.10 [95%CI = -0.18 to -0.02]), verbal fluency (Hedges'g = -0.05 [95%CI = -0.10 to -0.00]), visual memory (Hedges'g = -0.21 [95%CI = -0.38 to -0.03]), and working memory (Hedges'g = -0.16 [95%CI = -0.28 to -0.04]). Meta-regression revealed that general cognition associated with PEs was related to younger age (z = 3.37, p = 0.001), male sex (z = -2.59, p = 0.010), and cognitive assessment before PE assessment (z = -2.15, p = 0.031), whereas working memory in individuals with PEs was associated with concurrent cognitive and PE assessment (z = 6.19, p < 0.001). We failed to find moderating effect of the choice of PE assessment instrument or cognitive task on cognitive functioning in PEs. Additional analysis showed no significant difference in the performance of any cognitive domains between individuals with high-level versus low-level PEs. Limitations included studies primarily derived from Western countries, no social-cognitive domains, and varied PE measurement. In sum, PEs are associated with milder and more circumscribed cognitive impairment relative to psychotic disorders. Future research is required to clarify differential cognitive trajectories between individuals with transient PEs and persistent/recurrent-PEs.

Measuring the concurrent validity of the norwegian versions of the psychotic symptom rating scales (PSYRATS) and the positive scale from the positive and negative syndrome scale (PANSS)

PURPOSE

The Positive and Negative Syndrome Scale (PANSS) is one of the most commonly used assessment tools for measuring psychotic symptoms. The Psychotic Symptom Rating Scales (PSYRATS) is another instrument created specifically to assess delusions and auditory hallucinations. However, research on the concurrent validity of PSYRATS with PANSS is limited. There are also inconsistent findings regarding the association between the PSYRATS scales and the PANSS positive scale. The present study aims to add to the understanding of the concurrent validity of these measures, while also incorporating a broader measure of psychiatric symptoms (the symptom scale from the Global Assessment of Functioning Scale - split version, GAF-S).

MATERIALS AND METHODS

Spearman's Rank Order Correlations (rho) were calculated for scores from the PANSS positive scale, PSYRATS and GAF-S in a sample of 148 participants with psychotic disorders at three time points.

RESULTS

The findings indicate concurrent validity between PSYRATS and PANSS, while the PSYRATS scales were not consistently correlated with GAF-S.

CONCLUSIONS

PSYRATS may be a valid assessment tool for evaluating psychotic symptoms. The utility of PSYRATS in research and clinical practice should be investigated further.

Psychosis detection in dementia: a systematic review of diagnostic test accuracy studies

Introduction

Symptoms of psychosis, characterized by delusions and hallucinations, are commonly experienced by persons living with dementia. A systematic review was completed to identify tools to evaluate symptoms of psychosis compared to a reference standard in persons with dementia. Articles reporting correlation values between psychosis tools were also identified.

Methods

The search concepts psychosis, dementia, and diagnostic accuracy were used to search MEDLINE, PsycINFO, and Embase. Included articles meeting the primary objective described a tool to assess symptoms of psychosis, delusions, or hallucinations in persons with dementia, a reference standard form of diagnostic assessment for psychosis, and diagnostic accuracy outcomes for the psychosis tool. Secondary objective articles reported correlation values between two or more psychosis tools in persons with dementia.

Results

One study met the primary objective and described the sensitivity and specificity of the Neuropsychiatric Inventory (NPI) and Columbia University Scale for Psychopathology in Alzheimer's Disease (CUSPAD) in identifying symptoms of psychosis, hallucinations, and delusions. The sensitivity of the NPI and CUSPAD in identifying symptoms of psychosis was 83 and 90%, respectively. Nine studies meeting the secondary objective described eleven unique tools and examined the degree to which tools used to assess psychotic symptoms in persons with dementia were related.

Discussion

The NPI and CUSPAD were identified in a single study as psychosis tools that have been evaluated against a reference standard of psychosis assessment in persons with dementia. Various tools to assess the burden of psychotic symptoms in persons with dementia exist, but the diagnostic accuracy of existing tools remains understudied. Further research on the comparative utility and diagnostic accuracy is required for all psychosis tools used with persons with dementia.

Using brain structural neuroimaging measures to predict psychosis onset for individuals at clinical high-risk

Machine learning approaches using structural magnetic resonance imaging (sMRI) can be informative for disease classification, although their ability to predict psychosis is largely unknown. We created a model with individuals at CHR who developed psychosis later (CHR-PS+) from healthy controls (HCs) that can differentiate each other. We also evaluated whether we could distinguish CHR-PS+ individuals from those who did not develop psychosis later (CHR-PS-) and those with uncertain follow-up status (CHR-UNK). T1-weighted structural brain MRI scans from 1165 individuals at CHR (CHR-PS+, n = 144; CHR-PS-, n = 793; and CHR-UNK, n = 228), and 1029 HCs, were obtained from 21 sites. We used ComBat to harmonize measures of subcortical volume, cortical thickness and surface area data and corrected for non-linear effects of age and sex using a general additive model. CHR-PS+ (n = 120) and HC (n = 799) data from 20 sites served as a training dataset, which we used to build a classifier. The remaining samples were used external validation datasets to evaluate classifier performance (test, independent confirmatory, and independent group [CHR-PS- and CHR-UNK] datasets). The accuracy of the classifier on the training and independent confirmatory datasets was 85% and 73% respectively. Regional cortical surface area measures-including those from the right superior frontal, right superior temporal, and bilateral insular cortices strongly contributed to classifying CHR-PS+ from HC. CHR-PS- and CHR-UNK individuals were more likely to be classified as HC compared to CHR-PS+ (classification rate to HC: CHR-PS+, 30%; CHR-PS-, 73%; CHR-UNK, 80%). We used multisite sMRI to train a classifier to predict psychosis onset in CHR individuals, and it showed promise predicting CHR-PS+ in an independent sample. The results suggest that when considering adolescent brain development, baseline MRI scans for CHR individuals may be helpful to identify their prognosis. Future prospective studies are required about whether the classifier could be actually helpful in the clinical settings.

Development and preliminary validation of the Postpartum Psychotic Experiences Scale (PPES)

Despite the emerging research interest in postpartum psychotic experiences, there is still a lack of measures for specifically measuring this construct. The contribution of this paper is to design and validate a novel self-report measure, the Postpartum Psychotic Experiences Scale (PPES), to screen for attenuated psychotic symptoms during postpartum. This cross-sectional study was conducted from September 2022 until June 2023, enrolling 438 women 4-6 weeks after delivery. Starting from an initial pool of 22 items, both Exploratory Factor Analysis and Confirmatory Factor Analysis suggested that remaining 15 items loaded on one factor (α = 0.95). The PPES showed good convergent validity with the Prodromal Questionnaire-Brief scale (correlations >0.8) and good concurrent validity with postpartum depression and anxiety scales. A PPSE score of 8.5 (sensitivity=85.2%, specificity=78.6%) was defined as the optimal cutoff point. At this cutoff, 47% of participating women were considered at possible risk for postpartum psychosis. This study provides, for the first time, a specific self-report measure to assess postpartum PEs reliably and validly. We hope that the PPES will facilitate routine screening for PEs after childbirth among women who are predisposed to developing postpartum psychosis.

Understanding psychosis

ABSTRACT

Psychotic behavior is often unpredictable; thus, there can be an increased risk of violence toward others and oneself. This article details the etiology and diagnosis of psychosis and nursing interventions to provide appropriate care.

White matter, cognition and psychotic-like experiences in UK Biobank

BACKGROUND

Psychotic-like experiences (PLEs) are risk factors for the development of psychiatric conditions like schizophrenia, particularly if associated with distress. As PLEs have been related to alterations in both white matter and cognition, we investigated whether cognition (g-factor and processing speed) mediates the relationship between white matter and PLEs.

METHODS

We investigated two independent samples (6170 and 19 891) from the UK Biobank, through path analysis. For both samples, measures of whole-brain fractional anisotropy (gFA) and mean diffusivity (gMD), as indications of white matter microstructure, were derived from probabilistic tractography. For the smaller sample, variables whole-brain white matter network efficiency and microstructure were also derived from structural connectome data.

RESULTS

The mediation of cognition on the relationships between white matter properties and PLEs was non-significant. However, lower gFA was associated with having PLEs in combination with distress in the full available sample (standardized β = -0.053, p = 0.011). Additionally, lower gFA/higher gMD was associated with lower g-factor (standardized β = 0.049, p < 0.001; standardized β = -0.027, p = 0.003), and partially mediated by processing speed with a proportion mediated of 7% (p = < 0.001) for gFA and 11% (p < 0.001) for gMD.

CONCLUSIONS

We show that lower global white matter microstructure is associated with having PLEs in combination with distress, which suggests a direction of future research that could help clarify how and why individuals progress from subclinical to clinical psychotic symptoms. Furthermore, we replicated that processing speed mediates the relationship between white matter microstructure and g-factor.

The association between clinical symptoms and later subjective quality of life in individuals with ultra-high risk for psychosis and recent-onset psychotic disorder: A longitudinal investigation

AIM

Subjective quality of life is a clinically relevant outcome that is strongly associated with the severity of clinical symptoms in individuals with ultra-high risk for psychosis and patients with recent-onset psychotic disorder. Our objective was to examine whether longitudinal changes in clinical symptoms are associated with quality of life in ultra-high risk individuals and patients with recent-onset psychotic disorder.

METHODS

Individuals with ultra-high risk and patients with recent-onset psychosis disorder were recruited in the same clinical settings at baseline and were followed up with more than 6 months and less than 5 years later. We assessed five factors of clinical symptoms using the positive and negative syndrome scale, and quality of life using the World Health Organization quality of life questionnaire-short form. We used multiple regression to examine the relationships between clinical symptoms and quality of life while controlling for diagnosis, follow-up period, age, and sex.

RESULTS

Data were collected from 22 individuals with ultra-high risk and 27 patients with recent-onset psychosis disorder. The multiple regression analysis results indicated that the more severe anxiety/depression was at baseline, the poorer the quality of life at follow-up. Further, improvement of anxiety/depression and disorganized thoughts were associated with improvement in quality of life. The difference in diagnosis did not affect the association between clinical symptoms and quality of life.

CONCLUSION

These findings suggest that the improvement of anxiety/depression and disorganized thoughts is important in the early stages of psychosis before it becomes severe, affecting the quality of life.

Co-occurring psychotic and eating disorders in England: findings from the 2014 Adult Psychiatric Morbidity Survey

BACKGROUND

Psychotic disorders and eating disorders are complex mental illnesses associated with increased mortality and functional impairment. This study aimed to investigate the co-occurrence and relationships between eating disorders and psychotic disorders and assess the mediation effect of mood instability.

METHODS

This study used data from the Adult Psychiatric Morbidity Survey (APMS) 2014, a general population-based survey in England. Participants (total N = 7546, female N = 4488, male N = 3058, mean age = 52.3 years) were categorised based on psychotic disorder status into the groups of probable psychosis, diagnosed psychosis, and healthy controls without psychosis. The dependent variable of this study was the presence or absence of an eating disorder, with mood instability as the mediator. Logistic regression and mediation analyses were conducted to assess the relationships between these variables.

RESULTS

Both probable and diagnosed psychoses were significantly related to the presence of an eating disorder, and mood instability was found to be a mediating variable with moderate effect.

CONCLUSION

The present study demonstrates a significant relationship between eating disorders and psychotic disorders in the English general population, indicating higher levels of co-occurrence between these two groups of disorders than when compared with healthy controls. The findings also suggest the relationship between eating and psychotic disorders is mediated, to an extent, by the presence of mood instability traits. Future research could extend the present study's findings through assessing whether specific eating disorders are more significantly related to psychotic disorders than others.

Psychotic-like experiences from adolescence to adulthood: A longitudinal study

Psychotic-like experiences (PLEs), such as delusions and hallucinations, are regarded to occur along a spectrum and to be present also in non-help-seeking individuals from the general population. However, it remains unclear whether the occurrence of PLEs is a unique risk factor for future PLEs or a symptom of general psychopathology. In this study, we investigated whether PLEs during adolescence predict future PLEs in adulthood. A community-based cohort of 1146 young adolescents (mean age, 14.38 years) were assessed and then reassessed 6 years later (mean age, 20.15 years). Participants reported PLEs experienced in the past year, as well as symptoms of depression, anxiety, attention-deficit/hyperactivity disorder, and conduct problems. We adjusted the analysis for other forms of psychopathology and sex differences. Participants who reported PLEs in adulthood had higher ratings for all preceding and co-occurring symptoms of psychopathology. In the adjusted logistic regression model, having PLEs and, to a smaller degree, anxiety during adolescence predicted PLEs in early adulthood. The association between baseline and future PLEs did not differ between males and females, although females were more likely to report PLEs during adolescence. Participants with persistent PLEs reported more hallucinations during adolescence than those with transient symptoms. Our findings suggest that the early occurrence of PLEs is an important and independent predictor of future PLEs and should be monitored to identify individuals with a high risk of future psychopathology and to enable early interventions.

Genetic and psychosocial stressors have independent effects on the level of subclinical psychosis: findings from the multinational EU-GEI study

AIMS

Gene x environment (G×E) interactions, i.e. genetic modulation of the sensitivity to environmental factors and/or environmental control of the gene expression, have not been reliably established regarding aetiology of psychotic disorders. Moreover, recent studies have shown associations between the polygenic risk scores for schizophrenia (PRS-SZ) and some risk factors of psychotic disorders, challenging the traditional gene v. environment dichotomy. In the present article, we studied the role of GxE interaction between psychosocial stressors (childhood trauma, stressful life-events, self-reported discrimination experiences and low social capital) and the PRS-SZ on subclinical psychosis in a population-based sample.

METHODS

Data were drawn from the EUropean network of national schizophrenia networks studying Gene-Environment Interactions (EU-GEI) study, in which subjects without psychotic disorders were included in six countries. The sample was restricted to European descendant subjects (n = 706). Subclinical dimensions of psychosis (positive, negative, and depressive) were measured by the Community Assessment of Psychic Experiences (CAPE) scale. Associations between the PRS-SZ and the psychosocial stressors were tested. For each dimension, the interactions between genes and environment were assessed using linear models and comparing explained variances of 'Genetic' models (solely fitted with PRS-SZ), 'Environmental' models (solely fitted with each environmental stressor), 'Independent' models (with PRS-SZ and each environmental factor), and 'Interaction' models (Independent models plus an interaction term between the PRS-SZ and each environmental factor). Likelihood ration tests (LRT) compared the fit of the different models.

RESULTS

There were no genes-environment associations. PRS-SZ was associated with positive dimensions (β = 0.092, R² = 7.50%), and most psychosocial stressors were associated with all three subclinical psychotic dimensions (except social capital and positive dimension). Concerning the positive dimension, Independent models fitted better than Environmental and Genetic models. No significant GxE interaction was observed for any dimension.

CONCLUSIONS

This study in subjects without psychotic disorders suggests that (i) the aetiological continuum hypothesis could concern particularly the positive dimension of subclinical psychosis, (ii) genetic and environmental factors have independent effects on the level of this positive dimension, (iii) and that interactions between genetic and individual environmental factors could not be identified in this sample.

Psychotic symptoms in bipolar disorder and their impact on the illness: A systematic review

BACKGROUND

Lifetime psychotic symptoms are present in over half of the patients with bipolar disorder (BD) and can have an adverse effect on its course, outcome, and treatment. However, despite a considerable amount of research, the impact of psychotic symptoms on BD remains unclear, and there are very few systematic reviews on the subject.

AIM

To examine the extent of psychotic symptoms in BD and their impact on several aspects of the illness.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed. An electronic literature search of six English-language databases and a manual search was undertaken to identify published articles on psychotic symptoms in BD from January 1940 to December 2021. Combinations of the relevant Medical Subject Headings terms were used to search for these studies. Articles were selected after a screening phase, followed by a review of the full texts of the articles. Assessment of the methodological quality of the studies and the risk of bias was conducted using standard tools.

RESULTS

This systematic review included 339 studies of patients with BD. Lifetime psychosis was found in more than a half to two-thirds of the patients, while current psychosis was found in a little less than half of them. Delusions were more common than hallucinations in all phases of BD. About a third of the patients reported first-rank symptoms or mood-incongruent psychotic symptoms, particularly during manic episodes. Psychotic symptoms were more frequent in bipolar type I compared to bipolar type II disorder and in mania or mixed episodes compared to bipolar depression. Although psychotic symptoms were not more severe in BD, the severity of the illness in psychotic BD was consistently greater. Psychosis was usually associated with poor insight and a higher frequency of agitation, anxiety, and hostility but not with psychiatric comorbidity. Psychosis was consistently linked with increased rates and the duration of hospitalizations, switching among patients with depression, and poorer outcomes with mood-incongruent symptoms. In contrast, psychosis was less likely to be accompanied by a rapid-cycling course, longer illness duration, and heightened suicidal risk. There was no significant impact of psychosis on the other parameters of course and outcome.

CONCLUSION

Though psychotic symptoms are very common in BD, they are not always associated with an adverse impact on BD and its course and outcome.

Toward recovery in schizophrenia: Current concepts, findings, and future research directions

Schizophrenia was initially defined as "dementia praecox" by E. Kraepelin, which implies progressive deterioration. However, recent studies have revealed that early effective intervention may lead to social and functional recovery in schizophrenia. In this review, we provide an overview of current concepts in schizophrenia and pathophysiological hypotheses. In addition, we present recent findings from clinical and basic research on schizophrenia. Recent neuroimaging and neurophysiological studies have consistently revealed specific biological differences in the structure and function of the brain in those with schizophrenia. From a basic research perspective, to determine the essential pathophysiology underlying schizophrenia, it is crucial that findings from all lines of inquiry-induced pluripotent stem cell (iPSC)-derived neural cells from patients, murine models expressing genetic mutations identified in patients, and patient clinical data-be integrated to contextualize the analysis results. However, the findings remain insufficient to serve as a diagnostic tool or a biomarker for predicting schizophrenia-related outcomes. Collaborations to conduct clinical research based on the patients' and their families' values are just beginning, and further development is expected.

Current psychotic-like experiences among adolescents in China: Identifying risk and protective factors

OBJECTIVE

This study aim to explore the prevalence of current PLEs over past month and relevant influential factors among adolescents.

METHODS

A total of 67,538 students completed one online survey between April 21st and May 12th, 2021. Current PLEs were assessed using the 8-item Positive Subscale of the Community Assessment of Psychic Experiences (CAPE-P8). Participants were defined as having frequent PLEs if they selected "often" or "nearly always" on one or more items of CAPE-P8. Family function, school climate and a series of socio-demographic were also evaluated.

RESULTS

In this sample, 49.3% adolescents reported having at least one PLE over the past month, while 15.4% experienced high frequent PLEs. Alcohol intake was positively associated with high frequent PLEs (OR = 2.61, 95% CI = 2.37-2.88). Adolescents with chronic physical illness (OR = 1.94, 95% CI = 1.73-2.18) or family history of psychiatric illness (OR = 2.61, 95% CI = 2.22-2.77) were more likely to suffer from high frequent PLEs. Dysfunction family function (OR _moderate = 1.98, 95% CI = 1.98-2.09; OR _severe = 6.98, 95% CI = 6.48-7.53) or poor school climate (OR = 3.14, 95% CI = 2.93-3.37) was associated with elevated high frequent PLEs.

CONCLUSIONS

Several factors of socio-demographics, unhealthy lifestyle, family and school environments are found to be related to frequent PLEs. These factors should also be taken into consideration for effective psychosocial intervention in adolescents.

Factors associated with late-life psychosis in primary care older adults without a diagnosis of dementia

PURPOSE

The epidemiology of late-life psychosis (LLP) remains unclear comparatively to early-onset psychosis. The study aims to estimate the prevalence and incidence of LLP over a 3-year period and examine the correlates of LLP in community-living older adults aged ≥ 65 years recruited in primary care.

METHODS

Study sample included N = 1481 primary care older adults participating in the Étude sur la Santé des Aînés (ESA)-Services study. Diagnoses were obtained from health administrative and self-reported data in the 3 years prior and following baseline interview. The prevalence and incidence of LLP (number of cases) were identified in the 3-year period following interview. Participants with dementia or psychosis related to dementia were excluded. Logistic regressions were used to ascertain the correlates of LLP as function of various individual and health system factors.

RESULTS

The 3-year prevalence and incidence of LLP was 4.7% (95% CI = 3.64-5.81) and 2.8% (95% CI = 1.99-3.68), respectively. Factors associated with both prevalent and incident LLP included functional status, number of physical diseases, hospitalizations, continuity of care and physical activity. Older age and the presence of suicidal ideation were associated with incident LLP, while higher education, a depressive disorder and a history of sexual assault were associated with persistent cases.

CONCLUSIONS

Results highlight the importance of LLP in primary care older adult patients without dementia. Health system factors were consistent determinants of prevalent and incident LLP, suggesting the need for better continuity of care in at-risk primary care older adults.

Distressing psychotic-like experiences, cognitive functioning and early developmental markers in clinically referred young people aged 8-18 years

PURPOSE

Neurocognitive difficulties and early childhood speech/motor delays are well documented amongst older adolescents and young adults considered at risk for psychosis-spectrum diagnoses. We aimed to test associations between unusual or psychotic-like experiences (PLEs), co-occurring distress/emotional symptoms, current cognitive functioning and developmental delays/difficulties in young people (aged 8-18 years) referred to Child and Adolescent Mental Health Services in South London, UK.

METHODS

Study 1 examined receptive language, verbal learning and caregiver-reported speech and motor delays/difficulties in a sample of 101 clinically-referred children aged 8-14 years, comparing those reporting no PLEs (n = 19), PLEs without distress (n = 16), and PLEs with distress (n = 66). Study 2 tested associations of severity of distressing PLEs with vocabulary, perceptual reasoning, word reading and developmental delays/difficulties in a second sample of 122 adolescents aged 12-18 years with distressing PLEs.

RESULTS

In Study 1, children with distressing PLEs had lower receptive language and delayed recall and higher rates of developmental delays/difficulties than the no-PLE and non-distressing PLE groups (F values: 2.3-2.8; p values: < 0.005). Receptive language (β = 0.24, p = 0.03) and delayed recall (β = - 0.17, p = 0.02) predicted PLE distress severity. In Study 2, the cognitive-developmental variables did not significantly predict PLE distress severity (β values = 0.01-0.22, p values: > 0.05).

CONCLUSION

Findings may be consistent with a cognitive-developmental model relating distressing PLEs in youth with difficulties in cognitive functioning. This highlights the potential utility of adjunctive cognitive strategies which target mechanisms associated with PLE distress. These could be included in cognitive-behavioural interventions offered prior to the development of an at-risk mental state in mental health, educational or public health settings.

What drives beliefs in COVID-19 conspiracy theories? The role of psychotic-like experiences and confinement-related factors

RATIONALE

The COVID-19 pandemic is a worldwide threat to public health and the global economy. The climate of fear and uncertainty associated with the pandemic has fostered the emergence of a wide range of COVID-19 conspiracy theories that have the potential to shape public opinion and hinder the effective dissemination of valid information. Beliefs in conspiracy theories have been associated with maladaptive personality traits such as schizotypy and paranoia, as well as other non-psychotic psychological characteristics (e.g., social isolation, stress).

METHODS

An online survey was conducted to examine the associations between beliefs in COVID-19 conspiracy theories and psychotic-like experiences in a Portuguese community sample (N = 438), while also addressing the role of sociodemographic variables, psychological outcomes (e.g., stress, affective states), confinement-related factors (e.g., confinement conditions/behaviors), and pandemic-related factors (e.g., health concerns, financial issues).

RESULTS

Findings suggest that psychotic-like experiences are associated with beliefs in COVID-19 conspiracy theories, particularly perceptual abnormalities and persecutory ideation. Moreover, increased health-related concerns and reduced education levels also seem to be liability factors for these conspiracy beliefs.

CONCLUSION

These results add important insights into how the adherence to illogical and erroneous disease-related arguments can be related to psychotic-like experiences. COVID-19 conspiracy theories are yet another major challenge that governments and policymakers must contemplate when defining strategic directions to manage the current and future pandemics.

Early persistence of psychotic-like experiences in a community sample of adolescents

AIMS

Psychotic-like experiences (PLEs) are common in adolescents. Their persistence may confer increased susceptibility to psychotic disorder. The early evolution of transient to persistent PLEs is not well known. This study aimed to investigate the early persistence of PLEs (over 6-12 months) in a community sample of adolescents and examine baseline and longitudinal associations of early persistent PLEs.

METHODS

Five hundred and ninety Year 10 students were administered the community assessment of psychic experiences (CAPE) to measure PLEs at baseline and at follow up 6-12 months later. Persistent PLEs were defined as those present at or above the 90th centile at both time points. Independent variables of depression, psychological distress and functioning were all measured at both baseline and follow up. Self-esteem, personality and suicidality were assessed at follow up.

RESULTS

The study found 5.1% of participants had early persistent PLEs. Persistence was associated positively with depression and distress at both time points, neuroticism and openness at baseline and suicidality at follow up. Persistence was negatively associated with functioning at both time points, agreeableness at baseline and self-esteem at follow-up. Only depression remained significantly associated at both time points when accounting for other variables. Thus, depressive symptoms may account for changes in other domains and be a predictor of early PLEs persistence.

CONCLUSIONS

These results reinforce the importance of monitoring and assessing PLEs in young people especially when associated with depression. Further research is required to investigate PLE persistence over longer periods with increased measurement intervals.

Nonclinical psychotic-like experiences and schizotypy dimensions: Associations with hippocampal subfield and amygdala volumes

Schizotypy and psychotic-like experiences (PLE) form part of the wider psychosis continuum and may have brain structural correlates in nonclinical cohorts. This study aimed to compare the effects of differential schizotypy dimensions, PLE, and their interaction on hippocampal subfields and amygdala volumes in the absence of clinical psychopathology. In a cohort of 367 psychiatrically healthy individuals, we assessed schizotypal traits using the Oxford-Liverpool Inventory of Life Experiences (O-LIFE) and PLE using the short form of the Prodromal Questionnaire (PQ-16). Based on high-resolution structural MRI scans, we used automated segmentation to estimate volumes of limbic structures. Sex and total intracranial volume (Step 1), PLE and schizotypy dimensions (Step 2), and their interaction terms (Step 3) were entered as regressors for bilateral amygdala and hippocampal subfield volumes in hierarchical multiple linear regression models. Positive schizotypy, but not PLE, was negatively associated with left amygdala and subiculum volumes. O-LIFE Impulsive Nonconformity, as well as the two-way interaction between positive schizotypy and PLE, were associated with larger left subiculum volumes. None of the estimators for right hemispheric hippocampal subfield volumes survived correction for multiple comparisons. Our findings support differential associations of hippocampus subfield volumes with trait dimensions rather than PLE, and support overlap and interactions between psychometric positive schizotypy and PLE. In a healthy cohort without current psychosis risk syndromes, the positive association between PLE and hippocampal subfield volume occurred at a high expression of positive schizotypy. Further studies combining stable, transient, and genetic parameters are required.

Recent Advances and Future Directions in Brain MR Imaging Studies in Schizophrenia: Toward Elucidating Brain Pathology and Developing Clinical Tools

Schizophrenia is a common severe psychiatric disorder that affects approximately 1% of general population through the life course. Historically, in Kraepelin's time, schizophrenia was a disease unit conceptualized as dementia praecox; however, since then, the disease concept has changed. Recent MRI studies had shown that the neuropathology of the brain in this disorder was characterized by mild progression before and after the onset of the disease, and that the brain alterations were relatively smaller than assumed. Although genetic factors contribute to the brain alterations in schizophrenia, which are thought to be trait differences, other changes include factors that are common in psychiatric diseases. Furthermore, it has been shown that the brain differences specific to schizophrenia were relatively small compared to other changes, such as those caused by brain development, aging, and gender. In addition, compared to the disease and participant factors, machine and imaging protocol differences could affect MRI signals, which should be addressed in multi-site studies. Recent advances in MRI modalities, such as multi-shell diffusion-weighted imaging, magnetic resonance spectroscopy, and multimodal brain imaging analysis, may be candidates to sharpen the characterization of schizophrenia-specific factors and provide new insights. The Brain/MINDS Beyond Human Brain MRI (BMB-HBM) project has been launched considering the differences and noises irrespective of the disease pathologies and includes the future perspectives of MRI studies for various psychiatric and neurological disorders. The sites use restricted MRI machines and harmonized multi-modal protocols, standardized image preprocessing, and traveling subject harmonization. Data sharing to the public will be planned in FY 2024. In the future, we believe that combining a high-quality human MRI dataset with genetic data, randomized controlled trials, and MRI for non-human primates and animal models will enable us to understand schizophrenia, elucidate its neural bases and therapeutic targets, and provide tools for clinical application at bedside.

Validation of the Korean Version of the Psychosis Screener to Identify Patients With Psychosis

OBJECTIVE

This study aimed to validate the Korean version of a short screening tool for psychosis as the first stage in finding undiagnosed psychosis in the community.

METHODS

The sample contained 126 consecutive psychiatric outpatients in National Medical Center, Seoul, Korea, between July 20 and July 22, 2020. The Psychosis Screener (PS) comprises 7 items covering psychotic symptoms. The presence of each psychotic symptom was determined by a trained mental health professional and coded "yes" or "no." Two psychiatrists reviewed the medical records independently and extracted the ICD-10-based diagnoses. Any differences between the two clinicians were resolved by consensus, and the agreed diagnosis was used as a gold standard in the study.

RESULTS

Among 126 psychiatric outpatients who were enrolled in a consecutive manner during the study period, the proportion of psychosis was 15.1%. The PS showed 78.9% sensitivity and 72.0% specificity when the optimal cut-off was 2, indicating that a score of 2 or more on the screener identified a likely case of psychosis. The area under the curve for the PS was 0.78 (95% CI: 0.67-0.87).

CONCLUSION

The Korean version of the PS has an ability to discriminate between those who meet the diagnostic criteria for psychosis and those who do not in a high-prevalence group.

Reduced cortical thickness of the paracentral lobule in at-risk mental state individuals with poor 1-year functional outcomes

Although widespread cortical thinning centered on the fronto-temporal regions in schizophrenia has been reported, the findings in at-risk mental state (ARMS) patients have been inconsistent. In addition, it remains unclear whether abnormalities of cortical thickness (CT) in ARMS individuals, if present, are related to their functional decline irrespective of future psychosis onset. In this multicenter study in Japan, T1-weighted magnetic resonance imaging was performed at baseline in 107 individuals with ARMS, who were subdivided into resilient (77, good functional outcome) and non-resilient (13, poor functional outcome) groups based on the change in Global Assessment of Functioning scores during 1-year follow-up, and 104 age- and sex-matched healthy controls recruited at four scanning sites. We measured the CT of the entire cortex and performed group comparisons using FreeSurfer software. The relationship between the CT and cognitive functioning was examined in an ARMS subsample (n = 70). ARMS individuals as a whole relative to healthy controls exhibited a significantly reduced CT, predominantly in the fronto-temporal regions, which was partly associated with cognitive impairments, and an increased CT in the left parietal and right occipital regions. Compared with resilient ARMS individuals, non-resilient ARMS individuals exhibited a significantly reduced CT of the right paracentral lobule. These findings suggest that ARMS individuals partly share CT abnormalities with patients with overt schizophrenia, potentially representing general vulnerability to psychopathology, and also support the role of cortical thinning in the paracentral lobule as a predictive biomarker for short-term functional decline in the ARMS population.

Delusions beyond beliefs: a critical overview of diagnostic, aetiological, and therapeutic schizophrenia research from a clinical-phenomenological perspective

Delusions are commonly conceived as false beliefs that are held with certainty and which cannot be corrected. This conception of delusion has been influential throughout the history of psychiatry and continues to inform how delusions are approached in clinical practice and in contemporary schizophrenia research. It is reflected in the full psychosis continuum model, guides psychological and neurocognitive accounts of the formation and maintenance of delusions, and it substantially determines how delusions are approached in cognitive-behavioural treatment. In this Review, we draw on a clinical-phenomenological framework to offer an alternative account of delusion that incorporates the experiential dimension of delusion, emphasising how specific alterations to self-consciousness and reality experience underlie delusions that are considered characteristic of schizophrenia. Against that backdrop, we critically reconsider the current research areas, highlighting empirical and conceptual issues in contemporary delusion research, which appear to largely derive from an insufficient consideration of the experiential dimension of delusions. Finally, we suggest how the alternative phenomenological approach towards delusion could offer new ways to advance current research and clinical practice.

Longitudinal Structural MRI Findings in Individuals at Genetic and Clinical High Risk for Psychosis: A Systematic Review

Background: Several cross-sectional studies report brain structure differences between healthy volunteers and subjects at genetic or clinical high risk of developing schizophrenia. However, longitudinal studies are important to determine whether altered trajectories of brain development precede psychosis onset. Methods: We conducted a systematic review to determine if brain trajectories differ between (i) those with psychotic experiences (PE), genetic (GHR) or clinical high risk (CHR), compared to healthy volunteers, and (ii) those who transition to psychosis compared to those who do not. Results: Thirty-eight studies measured gray matter and 18 studies measured white matter in 2,473 high risk subjects and 990 healthy volunteers. GHR, CHR, and PE subjects show an accelerated decline in gray matter primarily in temporal, and also frontal, cingulate and parietal cortex. In those who remain symptomatic or transition to psychosis, gray matter loss is more pronounced in these brain regions. White matter volume and fractional anisotropy, which typically increase until early adulthood, did not change or reduced in high risk subjects in the cingulum, thalamic radiation, cerebellum, retrolenticular part of internal capsule, and hippocampal-thalamic tracts. In those who transitioned, white matter volume and fractional anisotropy reduced over time in the inferior and superior fronto-occipital fasciculus, corpus callosum, anterior limb of the internal capsule, superior corona radiate, and calcarine cortex. Conclusion: High risk subjects show deficits in white matter maturation and an accelerated decline in gray matter. Gray matter loss is more pronounced in those who transition to psychosis, but may normalize by early adulthood in remitters.