Validation of the Prodromal Questionnaire-Brief in a representative sample of adolescents: Internal structure, norms, reliability, and links with psychopathology

Bodily experiences of trauma and psychosis risk

Bodily self-disturbances including anomalous embodiment of emotions are observed in psychosis-spectrum conditions. Psychosis is also associated with trauma exposure but the relationship between altered bodily experiences and trauma has not been extensively investigated in individuals at risk for psychosis (HR). We implemented a mapping task to localize felt sensations associated with trauma. Results show that trauma experiences were always localized in the body. HR reported increased rates of traumatic experiences than low-risk group (LR). HR reported sensations associated with trauma across widespread body areas. Further research is needed to elucidate how trauma might lead to psychotic-like experiences via bodily self-disturbances.

The diagnostic accuracy of screening for psychosis spectrum disorders in behavioral health clinics integrated into primary care

Screening for psychosis spectrum disorders in primary care could improve early identification and reduce the duration of untreated psychosis. However, the accuracy of psychosis screening in this setting is unknown. To address this, we conducted a diagnostic accuracy study of screening for psychosis spectrum disorders in eight behavioral health services integrated into primary care clinics. Patients attending an integrated behavioral health appointment at their primary care clinic completed the Prodromal Questionnaire - Brief (PQ-B) immediately prior to their intake assessment. This was compared to a diagnostic phone interview based on the Structured Interview for Psychosis Risk Syndromes (SIPS). In total, 145 participants completed all study procedures, of which 100 screened positive and 45 negative at a provisional PQ-B threshold of ≥20. The PQ-B was moderately accurate at differentiating psychosis spectrum from no psychosis spectrum disorders; a PQ-B distress score of ≥27 had a sensitivity and specificity of 71.2 % and 57.0 % respectively. In total, 66 individuals (45.5 %) met criteria for a psychosis spectrum disorder and 24 (16.7 %) were diagnosed with full psychosis, indicating a high prevalence of psychosis in the sample. Overall, screening for psychosis spectrum disorders in an IBH primary care setting identified a relatively high number of individuals and may identify people that would otherwise be missed. The PQ-B performed slightly less well than in population-based screening in community mental health settings. However, the findings suggest this may represent an effective way to streamline the pathway between specialty early psychosis programs and primary care clinics for those in need.

Intensity of Psychoactive Substance Use Affects the Occurrence of Prodromal Symptoms of Psychosis

BACKGROUND

Psychosis is defined as a series of symptoms that impair the mind and lead to a kind of loss of reference to reality. Development of psychosis is usually preceded by the appearance of prodromal symptoms. Numerous attempts have been made to find out how psychoactive substances can influence the onset and development of psychotic disorders, but to date there are no studies that show a link between the onset of prodromal symptoms and the use of psychoactive substances.

METHODS

A survey consisting of epidemiological and demographic questions, the Drug Use Disorders Identification Test (DUDIT), and the Prodromal Questionnaire Brief Version (PQ-B) was conducted on social media among users of illegal psychoactive substances, covering 703 study participants.

RESULTS

A total of 39.8% of the respondents had been treated by a psychiatrist, and the most popular drugs used by respondents in their lifetime were tetrahydrocannabinol-containing products, MDMA, amphetamines, and LSD. A significant correlation was found between the DUDIT and the PQ-B values.

CONCLUSIONS

Intensity of psychoactive substance use correlated positively with the risk of appearance and intensity of prodromal symptoms of psychosis. Early exposure to psychoactive substances increased the risk of heavy substance use in adulthood and led to more frequent prodromal states.

Measurement invariance across age, gender, ethnicity, and psychopathology of the Psychotic-Like Experiences Questionnaire for Children in a community sample

OBJECTIVES

The current study aimed to assess the measurement invariance of the 9-item self-report Psychotic-Like Experiences Questionnaire for Children (PLEQ-C) across various demographic (age, gender, ethnicity) and psychopathology profiles in a community sample of children.

METHODS

Children aged 9-11 years (n = 613; M age = 10.4 years [SD = 0.8]; 50.9% female) completed questionnaire screening at school, with primary caregivers returning questionnaires by mail from home. Configural, metric, scalar, and residual invariance of the PLEQ-C scores were investigated across groups differentiated by age (9; 10; 11 years), gender (female; male), ethnicity (white; black; other), and by child-reported and caregiver-reported psychopathology (abnormal rating; not abnormal).

RESULTS

The PLEQ-C scores demonstrated good unidimensional model fit. Full configural, metric, scalar, and residual invariance were demonstrated across gender, ethnicity, and psychopathology (both child- and caregiver-reported). Across age groups, the PLEQ-C scores showed full configural and metric invariance, but only partial scalar and residual invariance (with a single item measuring differently among 11-year-olds).

CONCLUSIONS

In this community sample, the PLEQ-C was robust to age, gender, ethnicity, and psychopathology profiles, providing evidence of its capacity to identify children in the general population who might benefit from further assessment to determine the clinical significance of their psychotic experiences.

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.

Comparing two measures of schizotypy and their relationship with psychological distress in British university students

AIMS

Schizotypy reflects the vulnerability to schizophrenia in the general population. Different questionnaires have been developed to measure aspects of schizotypy. Higher schizotypy scores have also been linked with depression, anxiety, and stress sensitivity. Here we examine the associations of schizotypy with symptoms of depression and anxiety in a sample of university students, using two different measures (N = 271).

METHODS

A series of confirmatory factor analyses was used to examine two distinct and frequently employed measures of schizotypy: the Community Assessment of Psychic Experiences (CAPE), and the Schizotypy Personality Questionnaire (SPQ). We assessed their relationship with each other and their predictive validity for anxiety, depression, and stress sensitivity.

RESULTS

Our results indicated the brief 7-factor SPQ (SPQ-BR) factor solution for the SPQ and the 15-item and 3 factor solution for the CAPE (i.e., CAPE-P15) as best fitting models. Particularly the CAPE dimension of persecutory ideation was a strong predictor of anxiety, depression, and stress sensitivity, whereas the SPQ dimensions of no close friends and social anxiety predicted psychological distress and stress in our student sample.

CONCLUSIONS

Our findings extend earlier work in general and patient samples and point to the importance of understanding the contribution of particularly positive schizotypy symptoms and different interpersonal aspects to psychological distress.

Longitudinal invariance of psychotic experiences in children and adolescents: What do the data tell us?

BACKGROUND

Psychotic experiences are common in adults, adolescents, and children. While usually self-limited, they can indicate psychosis proneness when persistent. The Community Assessment of Psychic Experiences (CAPE) measures lifetime psychotic experiences in three dimensions. The 20-item subscale addressing positive symptoms (CAPE-positive) is the most widely used. No study investigated its measurement invariance across timepoints during childhood and adolescence. This step is required to conduct reliable comparisons in longitudinal studies with different age groups.

METHODS

We used data from the Brazilian High-Risk Cohort, which enrolled 2511 individuals aged 6-12 years from public schools for the baseline evaluation. A 3-year follow-up assessment evaluated 1880 participants. Subjects were rated with the CAPE-positive and we performed, at each wave, a Multigroup Confirmatory Factor Analysis testing Exploratory and Confirmatory Factor Analysis models identified in a previous systematic review, to assess longitudinal invariance.

RESULTS

A three-factor solution was the best fitting model, comprising Persecutory Ideation, Bizarre Experiences and Perceptual Abnormalities. The longitudinal invariance analysis of the best-fit model was unsatisfactory, achieving only the metric level of invariance.

CONCLUSIONS

Our findings suggest that the CAPE-positive scale has good model fit indices for each evaluated time point individually (children and adolescents), but it is not invariant over time. Identifying which factors affect CAPE latent structure at different time points can improve our understanding of psychosis proneness and how to measure it.

The Influence of Insecure Attachment to Parents on Adolescents' Suicidality

Insecure attachment has been identified as a risk factor for adolescent psychopathology and, consequently, for suicidal behavior. We aimed to highlight the relationship between the attachment styles of adolescents and their suicidal behavior and to investigate the role of each parent in the suicidality pathway of adolescents. The sample consisted of 217 adolescent inpatients who were at the highest risk for suicidal behavior and who were hospitalized in the Unit for Intensive Child and Adolescent Psychiatry. Self-report questionnaires assessing their attachment to their parents, their acquired capability for attempting suicide, their suicidality, and a number of traumatic life events were administered. The results showed a higher level of attachment avoidance rather than attachment anxiety among the most at-risk adolescents. An acquired capability for suicide (ACS) mediated the positive correlation between adolescents' attachment avoidance in relation to the mother or father and their suicidality. The suppressive mediating effect of an ACS on the association between attachment anxiety in relation to the father and suicidality was detected. The odds ratio for attempted suicide was more than two times higher for adolescents who were insecurely attached to their father compared to adolescents who were insecurely attached to their mother. Our results confirmed the importance of attachment, especially paternal attachment, in developing suicidality during adolescence. Preventive and clinical interventions should target these important domains with the aim of decreasing suicidality among adolescents.

Prevalence and risk factors of self-reported psychotic experiences among high school and college students: A systematic review, meta-analysis, and meta-regression

BACKGROUND

Adolescents are at high risk of incident psychopathology. Fleeting psychotic experiences (PEs) that emerge in young people in response to stress may be warning signs that are missed by research that fails to study stressed populations, such as late high school and college/university students. Our aim in this systematic review was to conduct a meta-analysis that estimates prevalence rates of PEs in students, and to assess whether these rates differ by gender, age, culture, and COVID-19 exposure.

METHOD

We searched nine electronic databases, from their inception until January 31, 2022 for relevant studies. We pooled the estimates using the DerSimonian-Laird technique and random-effects meta-analysis. Our main outcome was the prevalence of self-reported PEs in high school and college/university students. We subsequently analyzed our data by age, gender, population, country, culture, evaluation tool, and COVID-19 exposure.

RESULTS

Out of 486 studies retrieved, a total of 59 independent studies met inclusion criteria reporting 210' 024 students from 21 different countries. Nearly one in four students (23.31%; 95% CI 18.41%-29.05%), reported having experienced PEs (heterogeneity [Q = 22,698.23 (62), p = 0.001] τ²  = 1.4418 [1.0415-2.1391], τ = 1.2007 [1.0205-1.4626], I²  = 99.7%, H = 19.13 [18.59-19.69]). The 95% prediction intervals were 04.01%-68.85%. Subgroup analyses showed that the pooled prevalence differed significantly by population, culture, and COVID-19 exposure.

CONCLUSION

This meta-analysis revealed high prevalence rates of self-reported PEs among teen and young adult students, which may have significance for mental health screening in school settings. An important realization is that PEs may have very different mental health meaning in different cultures.

Depressive traits are associated with a reduced effect of choice on intentional binding

A sense of agency (SoA) over wilful actions is thought to be dependent on the level of choice and the nature of the outcome. In a preregistered study, we manipulated choice and valence of outcome to assess the relationship between SoA across the depression and psychosis continuum. Participants (N = 151) completed a Libet Clock task, in which they had either a free or forced choice to press one of two buttons and received either a rewarding or punishing outcome. Participants also completed questionnaires on depressive and psychosis-like traits. Rewarding outcomes increased intentional binding. The evidence favoured no effect of choice on average, but this was influenced by inter-individual differences. Individuals reporting more depressive traits had less of a difference in intentional binding between free and forced choice conditions. We show that implicit SoA is sensitive to outcome valence and the effect of choice differs across the depression continuum.

Item-level endorsement on the Prodromal Questionnaire in a large non-clinical sample

BACKGROUND

Brief questionnaires, such as the Prodromal Questionnaire (PQ) positive scale, have been used to pre-screen individuals who may be at clinical high-risk (CHR) for psychosis. Despite the apparent utility of the PQ, few studies have examined response styles in non-clinical settings, which this study aimed to assess.

METHODS

Response frequencies were examined for PQ positive subscale items in 3584 students (ages 18-35) from a nationally representative, semi-public undergraduate institution. Highly endorsed items were evaluated further in conjunction with established cutoffs and associated symptom ratings from the Structured Interview for Psychosis-risk Syndromes (SIPS) in a smaller subset of participants (n = 162). Positive subscale and distressing item responses were also evaluated by gender, race, and ethnicity using measurement invariance analyses and by comparing the relative proportion of individuals above established cutoffs.

RESULTS

Fifteen symptoms were endorsed by over 20 % of the sample with as high as 71 % of respondents endorsing them. Responses to 12 of these items were not associated with ratings on the SIPS. The PQ functioned similarly across demographic characteristics with strong evidence found for gender and race invariance across items and strong ethnicity invariance and partial invariance for positive subscale items and distressing items, respectively.

CONCLUSIONS

These findings suggest that a commonly used psychosis-risk questionnaire may not be appropriate for non-clinical samples, with the possibility of high false positive rates of those at CHR for psychosis. Future large-scale epidemiological studies should evaluate if psychosis-risk screeners can be improved to identify CHR individuals in community settings.

Neurobehavioral Dimensions of Prader Willi Syndrome: Relationships Between Sleep and Psychosis-Risk Symptoms

Background

Prader Willi Syndrome (PWS) is a genetic disorder caused by the absence of expression of the paternal copies of maternally imprinted gene(s) located at 15q11-q13. While the physical and medical characteristics of PWS, including short stature, hyperphagia and endocrine dysfunction are well-characterized, systematic investigation of the long-recognized psychiatric manifestations has been recent.

Methods

Here, we report on the first remote (web-based) assessment of neurobehavioral traits, including psychosis-risk symptoms (Prodromal Questionnaire-Brief Version; PQ-B) and sleep behaviors (Pittsburgh Sleep Quality Index), in a cohort of 128 participants with PWS, of whom 48% had a paternal deletion, 36% uniparental disomy, 2.4% an imprinting mutation and 13% unknown mutation (mean age 19.3 years ± 8.4; 53.9% female). We aimed to identify the most informative variables that contribute to psychosis-risk symptoms. Multiple domains of cognition (accuracy and speed) were also assessed in a subset of PWS participants (n = 39) using the Penn Computerized Neurocognitive Battery (Penn-CNB).

Results

Individuals with PWS reported a range of psychosis-risk symptoms, with over half reporting cognitive disorganization (63.1%) and about one third reporting unusual beliefs (38.6%) and/or suspiciousness (33.3%). Subjectively-reported sleep quality, nap frequency, sleep duration, sleep disturbance, and daytime dysfunction were significant predictors of psychosis-risk symptom frequency and severity (all p's < 0.029). Sleep disturbance ratings were the strongest predictors of psychosis-risk symptoms. Regarding cognition, individuals with PWS showed the most prominent deficits in accuracy on measures of social cognition involving faces, namely Face Memory, Age Differentiation and Emotion Recognition, and greatest slowing on measures of Attention and Emotion Recognition. However, there were no significant differences in psychosis-risk symptoms or cognitive performance as a function of PWS genetic subtype.

Conclusions

PWS is associated with a high prevalence of distressing psychosis-risk symptoms, which are associated with sleep disturbance. Findings indicate that self/parent-reported neurobehavioral symptoms and cognition can be assessed remotely in individuals with PWS, which has implications for future large-scale investigations of rare neurogenetic disorders.

Cross-Sectional Descriptive Pilot Study on the Risk of Psychotic Disorders among Adolescents

Background: Adolescence is a key stage for the development of different mental disorders, particularly psychotic disorders. This stage of life is accompanied by new habits or behaviours that can make a person more vulnerable to developing a psychotic disorder or, on the contrary, play a protective role. Objective: To study the vulnerability to developing a psychotic disorder in adolescents and to analyse the main risk factors. Materials and methods: This is an observational, descriptive and cross-sectional study. The data collection was conducted using the Prodromal Questionnaire Brief Version (PQ-B) test and a self-developed questionnaire based on the vulnerability–stress model. Results: Of the total sample (n = 44), 65.9% were male and 100% lived in a rural environment. In general, among risk factors (stress, alcohol and cannabis consumption, history, bullying, traumatic event and sedentary lifestyle), alcohol consumption and the presence of stress were found to have high values. Furthermore, a risk of psychosis was found in 38.6% of the studied population. Of this percentage of adolescents at risk, 64.7% consumed alcohol (p = 0.99) and 82.4% suffered from stress (p = 0.7161). The protective factor (physical activity) was found in more than half (59% p = 0.16). Conclusions: There is a high risk of psychosis among the young adolescents assessed in this study, where the explanatory factors identified with higher values were alcohol consumption and the presence of stress.

Assessing self-reported clinical high risk symptoms: The psychometric properties of the polish version of the prodromal questionnaire-brief and a proposal for an alternative approach to scoring

BACKGROUND

Psychotic-like experiences (PLEs) might occur in the general population as low-risk individual differences or prodromal features, requiring quick detection and early intervention. The aims of this study were to conduct a mini-systematic review of the prognostic abilities of the Prodromal Questionnaire-Brief (PQ-B), describe the PLEs distribution for the first time in a Polish population, assess PQ-B reliability and propose an innovative scoring approach based on cluster analysis.

METHODS

Five hundred and twenty eight (334 female) adult volunteers underwent screening with the PQ-B, 49% also underwent the early psychosis screening test PRIME, to verify the tests' psychometric properties, to compare the prognostic accuracy of the PQ-B to the more restrictive PRIME, and to the detected types of possible diagnosis in the general population.

RESULTS

Almost 70% of respondents met the prognostic criteria of the PQ-B while only 30.6% met the PRIME criteria. Both tests proved reliable (α > .835) and valid (rho >.710; P < .001). A cluster analysis identified three different sub-groups detected with the PQ-B: healthy individuals without PLE; healthy with low-distressing PLEs; and possibly prodromal subjects reporting less frequent but more distressing PLEs and no worries about their own mental state. Also in systematic reviews, authors of different adaptations have observed that the PQ-B has too low specificity and postulated the need for higher cut-offs.

CONCLUSION

Study provides evidence of good reliability and sensitivity of the PQ-B in assessing PLEs among the general population, but emphasizes that straightforward quantitative scoring criteria are still unclear. A more qualitative approach might be useful for differentiating true prodromal subjects from clinically low-risk individual differences.

Psychotic-like experiences among 9,564 Kenyan adolescents and young adults

OBJECTIVE

To investigate the prevalence and characteristics of psychotic-like experiences (PLE) in a large cohort of Kenyan adolescents and young adults.

METHOD

The Washington Early Recognition Center Affectivity and Psychosis (WERCAP) Screen was used to the study the 12-month prevalence of PLE's among 9,564 Kenyan youths (aged 15-25 yrs), and the rates of psychosis high-risk (HR) and medium-risk (MR) cases, based on cut-off scores. Relationships with clinical, demographic and economic profiles were investigated.

RESULTS

Across all participants, 72% reported having had at least one PLE over the last year. 4.6% and 30.6% were HR and MR based on symptom scores. There were similar PLE rates in females and males. PLE severity correlated with mood (r=0.67), stress (r=0.46), and autistic traits (r=0.18). PLE severity was also related to poverty, lower education attainment, and underemployment. Compared to controls, HR and MR youths were more likely to report lifetime substance use and to have more significant use.

CONCLUSION

Psychosis screening can provide valuable information about individuals and may help identify those who may require clinical assessment and intervention to improve outcomes. This is particularly relevant in many parts of Africa where the resources are limited for treating more advanced illness.

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.

Screening of the college students at clinical high risk for psychosis in China: a multicenter epidemiological study

BACKGROUND

To investigate a 3-stage screening procedure and explore the clinical features of subjects at Clinical High Risk (CHR) for psychosis in a representative sample of Chinese college students.

METHODS

An epidemiological survey of the prevalence of the CHR syndrome in Chinese college students that was selected by stratified random sampling from Shanghai, Nanjing and Nanchang cities was done following a 3-stage procedure. Participants were initially screened with the Prodromal Questionnaire-brief version (PQ-B), and whose distress score of PQ-B exceeded 24 would be invited to a telephone assessment using the subscale for positive symptoms of the Scale of Prodromal Symptoms (SOPS)/Structured Interview for Prodromal Syndromes (SIPS). Lastly, participants who scored 3 or higher in any item of the subscale would be administered with the SIPS interview conducted by trained researchers to confirm the diagnosis of CHR syndrome.

RESULTS

Twenty-three thousand sixty-three college students completed the survey during September 2017 to October 2018. Seventy-two students were diagnosed as CHR subjects, and the detection rate in the total sample was 0.3%. The peak age range for the first diagnosis of CHR was 17 to 20 years. Thirteen and forty-six were set as the cutoff points of PQ-B total score and distress score to balance the greatest sensitivity and specificity. Binary logistic regression revealed that 8 items in PQ-B showed significant distinction for detecting CHR subjects.

CONCLUSIONS

The 3-stage screening method can be utilized in the detection of CHR subjects for psychosis in the general population, during which delusional ideas, perceptual abnormalities and suspiciousness deserve great attention.

Markers of Psychosis Risk in the General Population

The categorical approach to defining schizophrenia spectrum disorders requires meeting established criteria. To advance early identification and intervention in young people, the field has progressed to studying help-seeking individuals who are at clinical high risk based on subthreshold psychosis spectrum symptoms, and criteria have been articulated for qualifying individuals as at risk. A broader dimensional examination of psychosis has been applied to population-based studies on non-help seekers. This review highlights the ascertainment and assessment approaches to such population-based studies. Most studies are cross-sectional and rely on questionnaires with limited overlap of tools. However, several consistent findings emerge on symptoms, neurocognitive deficits, and neuroimaging parameters and other biomarkers associated with emergence and persistence of psychotic features. The findings are consistent with the literature on abnormalities associated with schizophrenia, including the presence of neurocognitive deficits; abnormalities in brain structure, function, and connectivity that are related to distress; impairment; and functional outcome. These findings support the validity of studying psychosis experiences during development in a way that can chart the emergence of psychosis in the context of general psychopathology. Such studies are necessary for establishing developmental trajectories that characterize this emergence and for identifying risk and resilience biomarkers moderating or modulating the full range of schizophrenia-related manifestations. More community-based studies are needed, with better standardization and harmonization of measures and incorporating longitudinal follow-up, to establish mechanistic links between cellular-molecular aberrations and specific manifestations of psychosis as envisioned by the precision medicine agenda.

An item response theory analysis of the Prodromal Questionnaire-Brief Child Version: Developing a screening form that informs understanding of self-reported psychotic-like experiences in childhood

The Prodromal Questionnaire-Brief Child Version (PQ-BC) has been developed as a tool for identifying psychotic-like experiences (PLEs) in school-age children. The current study examined the psychometric properties of the PQ-BC, examined how well the PQ-BC estimates the latent construct of PLEs (θ̂), and began the process of developing a screening form informed by item response theory (IRT). Utilizing the baseline (N = 11,129) sample from the Adolescent Brain Cognitive Development study, we examined which PQ-BC items provide the most information and best discriminate individuals experiencing PLEs. Using hierarchical linear models (HLMs), we found that θ̂ scores were significantly associated with several previously identified predictors of psychosis spectrum symptoms (i.e., history of psychosis, internalizing symptoms, cognitive impairments, developmental milestone delays, and resting-state functional connectivity impairments) at baseline and Year 1 (n = 5,532). Using item-level information and discrimination parameters of the PQ-BC from the baseline sample, we created a 7-item screening form. HLMs generally found significant associations between screening form scores for both baseline and Year 1 with the aforementioned predictors. The analyses provide evidence for the validity of a screening form derived from the PQ-BC using IRT-derived parameters. This screening form could prove useful when the full measure is not feasible. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

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.

Measurement Invariance of Psychotic-Like Symptoms as Measured With the Prodromal Questionnaire, Brief Version (PQ-B) in Adolescent and Adult Population Samples

Valid measurement of group differences in self-reported psychotic-like experiences (PLEs) requires knowing any group-specific measurement properties of the instruments. We investigated the measurement invariance of the 21-item Prodromal Questionnaire-Brief (PQ-B) questionnaire across gender, ethnic minority/majority status, and presence of depressive symptoms in two different US non-clinical undergraduate samples (N = 1,099). For each item, endorsement of the experience and the associated distress were combined for analysis. A unidimensional model of the PQ-B fit the data well. Across genders, the PQ-B showed configural and metric, but not full scalar invariance; there were statistically significant differences in eight thresholds of six items, most being higher endorsement thresholds for self-identified females. Partial scalar invariance was also found for ethnic status, with five thresholds of three items being higher for the minority participants. For depressive symptomatology, defined as the top quintile by the Beck Depression Inventory-II, partial scalar invariance required dropping one item, after which there were statistically significant differences only in two response thresholds. Overall, a wide range of PLE questionnaire items were found to be robust to gender and ethnicity effects, strengthening confidence in found group differences in PLEs. Although full scalar invariance could not be ascertained for any of the group comparisons, the few found scalar differences across groups were small, with minimal impact on group PLE estimates. However, since PLEs are easily conceptually entangled with depression symptoms, similar items should be considered for exclusion if separable constructs are the target of investigation.

Validation of the Prodromal Questionnaire-Brief in a representative sample of adolescents: Internal structure, norms, reliability, and links with psychopathology

OBJECTIVES

The main purpose of the present study was twofold: to validate the Prodromal Questionnaire-Brief (PQ-B) in a community-derived sample of adolescents and to examine the links between psychotic-like experiences and emotional and behavioral problems, prosocial behavior, suicidal ideation, and bipolar-like experiences.

METHOD

One thousand five hundred eighty-eight students selected by random sampling participated in a cross-sectional survey. The PQ-B, Paykel Suicide Scale, Strengths and Difficulties Questionnaire, Mood Disorder Questionnaire, Penn Matrix Reasoning Test, Family Affluence Scale-II, and Oviedo Infrequency Scale were used.

RESULTS

The unidimensional factorial structure of the PQ-B items showed adequate goodness of fit index. This model also showed configural and strong invariance across gender. The internal consistency of the PQ-B total frequency score was 0.92. A high degree of overlap was found between psychotic-like experiences and emotional and behavioral problems, suicidal ideation, and bipolar-like experiences.

CONCLUSION

The PQ-B is a brief, easy, and reliable tool for screening psychotic-like experiences in adolescents from the general population. The assessment of risk for psychosis and its relationship with other psychopathological risk factors in a close-in strategy or two-stage process model may help us to enhance the early identification for youths at heightened risk for serious mental disorders.