A twin study of genetic and environmental determinants of abnormal persistence of psychotic experiences in young adulthood

Internal consistency and temporal stability of the Community Assessment of Psychic Experiences (CAPE): A reliability generalization meta-analysis

Psychotic experiences (PE) are prevalent in general and clinical populations and can increase the risk for mental disorders in young people. The Community Assessment of Psychic Experiences (CAPE) is a widely used measure to assess PE in different populations and settings. However, the current knowledge on their overall reliability is limited. We examined the reliability of the CAPE-42 and later versions, testing the role of age, sex, test scores, and clinical status as moderators. A systematic search was conducted on the Scopus, Web of Science, PubMed, EBSCOhost, ProQuest, and GoogleScholar databases. Internal consistency and temporal stability indices were examined through reliability generalization meta-analysis (RGMA). Moderators were tested through meta-regression analysis. From a pool of 1,015 records, 90 independent samples were extracted from 71 studies. Four versions showed quantitative evidence for inclusion: CAPE-42, CAPE-20, CAPE-P15, and CAPE-P8. Internal consistency indices were good (α/ω≈.725-0.917). Temporal stability was only analyzed for the CAPE-P15, yielding a moderate but not-significant effect (r=0.672). The evidence for temporal stability is scant due to the limited literature, and definitive conclusions cannot be drawn. Further evidence on other potential moderators such as adverse experiences or psychosocial functioning is required.

Psychotic experiences and negative symptoms from adolescence to emerging adulthood: developmental trajectories and associations with polygenic scores and childhood characteristics

BACKGROUND

Psychotic experiences and negative symptoms (PENS) are common in non-clinical populations. PENS are associated with adverse outcomes, particularly when they persist. Little is known about the trajectories of PENS dimensions in young people, nor about the precursory factors associated with these trajectories.

METHODS

We conducted growth mixture modelling of paranoia, hallucinations, and negative symptoms across ages 16, 17, and 22 in a community sample (N = 12 049-12 652). We then described the emergent trajectory classes through their associations with genome-wide polygenic scores (GPS) for psychiatric and educational phenotypes, and earlier childhood characteristics.

RESULTS

Three trajectory classes emerged for paranoia, two for hallucinations, and two for negative symptoms. Across PENS, GPS for clinical help-seeking, major depressive disorder, and attention deficit hyperactivity disorder were associated with increased odds of being in the most elevated trajectory class (OR 1.07-1.23). Lower education GPS was associated with the most elevated trajectory class for hallucinations and negative symptoms (OR 0.77-0.91). Conversely for paranoia, higher education GPS was associated with the most elevated trajectory class (OR 1.25). Trajectory class associations were not significant for schizophrenia, obsessive-compulsive disorder, bipolar disorder, or anorexia GPS. Emotional/behaviour problems and life events in childhood were associated with increased odds of being in the most elevated trajectory class across PENS.

CONCLUSIONS

Our results suggest latent heterogeneity in the development of paranoia, hallucinations, and negative symptoms in young people that is associated with specific polygenic scores and childhood characteristics.

Incidence and Persistence of Psychotic Experiences in the General Population: Systematic Review and Meta-Analysis

BACKGROUND AND HYPOTHESIS

Psychotic experiences (PEs) are associated with increased risk for mental disorders, in particular persistent PEs. PEs therefore might be useful within intervention research. We sought to systematically determine the incidence and persistence of PEs in the general population.

STUDY DESIGN

A double-blind search of databases (Embase, Pubmed PMC, Psychinfo, Medline, and Web of Science) from inception to January 2023 and data extraction, were conducted. Study quality was assessed using the NIH assessment tool. Random effects models were conducted to calculate pooled incidence rate per person-year and proportion of persistent PEs per year. Age and study design were all examined using subgroup analyses. Demographic, risk factors, and outcomes for incidence and persistence of PEs were reported in a narrative synthesis.

STUDY RESULTS

Using a double-blind screening method for abstract (k = 5763) and full text (k = 250) were screened. In total 91 samples from 71 studies were included, of which 39 were included in a meta-analysis (incidence: k = 17, n = 56 089; persistence: k = 22, n = 81 847). Incidence rate was 0.023 per person-year (95% CI [0.0129;0.0322]). That is, for every 100 people, 2 reported first onset PEs in a year. This was highest in adolescence at 5 per 100(13-17 years). The pooled persistence rate for PEs was 31.0% (95% CI [26.65,35.35]) This was highest in adolescence at 35.8%. Cannabis was particularly associated with incidence of PEs, and persistence of PEs were associated with multiple mental disorders.

CONCLUSIONS

Each year incidence of PEs is 2 of every 100 people, and persists each year in 31% of cases, this risk is highest in adolescents.

Psychotic-like experiences in non-clinical subgroups with and without specific beliefs

BACKGROUND

Assuming a transdiagnostic and extended psychosis phenotype, psychotic-like experiences (PLEs) and psychotic symptoms are on a phenomenological and temporal continuum between clinical and non-clinical populations. Recent research points towards differences in PLE proneness in different subgroups and clinical impact of different PLE subtypes. This study examines the prevalence of PLEs in three groups of individuals with and without specific sets of beliefs aiming to elucidate the question whether proneness to PLEs varies according to traditional versus less traditional supernatural beliefs.

METHODS

The anonymized 16-item version of the Prodromal Questionnaire (PQ-16) was used to assess PLEs in three groups including individuals with religious beliefs (RB), belief in esoterism and paranormal phenomena (EB), and those embedded in scientific evidence approach and scepticism towards para-scientific theories (non-believers, NB). Male and female participants between 18 and 90 years were eligible for participation.

RESULTS

The sample comprised 159 individuals including 41 RB individuals, 43 EB individuals, and 75 NB individuals. The mean PQ-16 score of the EB individuals (6.86 ± 4.13) was significantly higher compared to NB individuals (3.43 ± 2.99) and to RB individuals (3.38 ± 3.23) with almost twice the score (both p-values < 0.001). There was no significant difference between the PQ-16 scores of the NB group and the RB group (p = 0.935). No significant impact of age (p = 0.330) and gender (p = 0.061) was found on the PQ16-Score. Group affiliation to esoterism was associated with a higher PQ-16 score compared to group affiliation to religious beliefs (p < 0.001) and group affiliation to scepticism (p = 0.011), while the latter two did not differ significantly (p = 0.735). No significant difference was found between the three groups in the degree of distress related to the affirmatively answered PQ-16 items (p = 0.74).

CONCLUSION

Under the assumption of a transdiagnostic psychosis phenotype, our findings provide more insight which subgroups within non-clinical samples have a higher likelihood of reporting PLEs.

Genetic and Geographical Associations With Six Dimensions of Psychotic Experiences in Adolesence

BACKGROUND AND HYPOTHESIS

Large-scale epidemiological and genetic research have shown that psychotic experiences in the community are risk factors for adverse physical and psychiatric outcomes. We investigated the associations of six types of specific psychotic experiences and negative symptoms assessed in mid-adolescence with well-established environmental and genetic risk factors for psychosis.

STUDY DESIGN

Fourteen polygenic risk scores (PRS) and nine geographical environmental variables from 3590 participants of the Twins Early Development Study (mean age 16) were associated with paranoia, hallucinations, cognitive disorganization, grandiosity, anhedonia, and negative symptoms scales. The predictors were modeled using LASSO regularization separately (Genetic and Environmental models) and jointly (GE model).

STUDY RESULTS

In joint GE models, we found significant genetic associations of negative symptoms with educational attainment PRS (β = -.07; 95% CI = -0.12 to -0.04); cognitive disorganization with neuroticism PRS (β = .05; 95% CI = 0.03-0.08); paranoia with MDD (β = .07; 95% CI = 0.04-0.1), BMI (β = .05; 95% CI = 0.02-0.08), and neuroticism PRS (β = .05; 95% CI = 0.02-0.08). From the environmental measures only family SES (β = -.07, 95% CI = -0.10 to -0.03) and regional education levels (β = -.06; 95% CI = -0.09 to -0.02) were associated with negative symptoms.

CONCLUSIONS

Our findings advance understanding of how genetic propensity for psychiatric, cognitive, and anthropometric traits, as well as environmental factors, together play a role in creating vulnerability for specific psychotic experiences and negative symptoms in mid-adolescence.

Subclinical psychotic symptoms in Indian adults: Application of the Community Assessment of Psychic Experiences (CAPE)

BACKGROUND

The study investigated the psychometric properties of the Community, Assessment of Psychic Experiences (CAPE-42), a self-report instrument in Indians.

METHOD

CAPE-42 was translated in Hindi and tested on 312 Indian adults recruited online and through paper-pencil assessment. Confirmatory factor analysis (CFA) was employed to establish the factor structure of the positive, negative and depressive dimensions of CAPE-42: the bifactor model was tested to evaluate whether items converge into a major single factor defining psychotic-proneness in individuals. Latent class analysis (LCA) was conducted to identify subgroups with a different endorsement of subclinical psychotic symptoms.

, RESULTS

CAPE-Hindi showed good reliability (Cronbach's alpha>0.80). CFA confirmed, a good fit for the bifactor model, factor loading was acceptable for all items in the general factor (Omega-h =0.83) and explained the primary variance of the subscales. Residual variance was explained by the positive, negative and depressive factors (Omega H =0.33, 0.04 and 0.12, respectively). LCA identified three classes traceable, to the three dimensions; a low endorsement group (n = 155; 50 %); a less consistent, group with endorsement on positive and depressive items (n = 117; 38 %), and a high, endorsement group (n = 40;13 %).

CONCLUSION

Hindi CAPE-42 showed good reliability and factorial validity.

Childhood trauma and schizotypy in non-clinical samples: A systematic review and meta-analysis

The association of early life adversities and psychosis symptoms is well documented in clinical populations; however, whether this relationship also extends into subclinical psychosis remains unclear. In particular, are early life adversities associated with increased levels of schizotypal personality traits in non-clinical samples? We conducted a systematic review and meta-analysis of associations between early life adversities and psychometrically defined schizotypal traits in non-clinical samples. The review followed PRISMA guidelines. The search using PubMed, Web of Science and EBSCO databases identified 1,609 articles in total. Twenty-five studies (N = 15,253 participants) met eligibility criteria for the review. An assessment of study quality showed that fewer than half of all studies were rated as methodologically robust. Meta-analyses showed that all forms of childhood abuse (emotional, physical and sexual) and neglect (emotional and physical) were significantly associated with psychometric schizotypy. The association of schizotypy traits with childhood emotional abuse (r = .33: 95%CI .30 to .37) was significantly larger than for all other form of abuse or neglect. Meta-regression analyses showed that the physical abuse-schizotypy relationship was stronger in samples with more women participants; and the sexual abuse-schizotypy relationship was stronger in younger samples. The current review identifies a dose-response relationship between all forms of abuse/neglect and schizotypy scores in non-clinical samples; however, a stronger association emerged for emotional abuse. More research is required to address the relationship of trauma types and specific symptom types. Future research should also address the under-representation of men.

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.

The Unique Contribution of Past Bullying Experiences to the Presence of Psychosis-Like Experiences in University Students

OBJECTIVES

Both bullying and psychosis-like experiences (PLEs) have gained much attention in recent years, but their interactions are not fully unraveled. The aim of the current study was to validate the Chinese version of Bullying Scale for Adults (C-BSA), and to investigate whether past bullying experiences independently predict the presence of PLEs in university students.

METHODS

The validity and reliability of the C-BSA were determined in two independent samples. A battery of psychological inventories was also administered to assess the presence of PLEs, maltreatment history in the family, and current depression and anxiety, including the 15-item positive subscale of the community assessment of psychic experiences (CAPE-p15), the Chinese version of the Childhood Trauma Questionnaire (CTQ), Self-Rating Depression Scale (SDS), and Self-Rating Anxiety Scale (SAS).

RESULTS

In the construction sample (N = 629), a Cronbach's α of 0.921 indicated a good internal consistency of C-BSA. The exploratory factor analysis (EFA) yielded a four-factor model and a three-factor model, and both were verified by using the confirmatory factorial analysis (CFA) in the validation sample (N = 629). The total scores of C-BSA were significantly correlated with that of CTQ, CAPE-p15, SDS, and SAS. Multivariate logistic regression revealed that bullying was associated with 2.0 or 3.7 times of risk for the presence of PLEs (numbers of bullying types < = 3 or > 3, respectively) after controlling for CTQ, SDS, and SAS scores.

CONCLUSIONS

C-BSA has shown good psychometric properties in college students. The contribution of past bullying experiences to the present PLEs seems to be independent of other childhood trauma, current depression, and anxiety.

Do environmental risk factors for the development of psychosis distribute differently across dimensionally assessed psychotic experiences?

Psychotic experiences (PE) are associated with poorer functioning, higher distress and the onset of serious mental illness. Environmental exposures (e.g. childhood abuse) are associated with the development of PE. However, which specific exposures convey risk for each type or dimension of PE has rarely been explored. The Oxford Wellbeing Life and Sleep (OWLS) survey includes 22 environmental risk factors for psychosis and was designed to examine how environmental risks are associated with specific dimensions of PE. Multivariate logistic regression models were fit using these risk factors to predict six dimensions of PE (perceptual abnormalities, persecutory ideation, bizarre ideas, cognitive disorganisation, delusional mood and negative symptoms). Models were built using only 70% of the data, and then fit to the remaining data to assess their generalisability and quality. 1789 (27.2% men; mean age = 27.6; SD = 10.9) survey responses were analysed. The risk factors predictive of the most PE were anxiety, social withdrawal during childhood and trauma. Cannabis and depression predicted three dimensions with both predicting bizarre ideas and persecutory ideation. Psychological abuse and sleep quality each predicted two dimensions (persecutory ideation and delusional mood). Risk factors predicting one PE dimension were age (predicting cognitive disorganisation), physical abuse (bizarre ideas), bullying and gender (persecutory ideation); and circadian phase (delusional mood). These results lend support for a continuum of psychosis, suggesting environmental risks for psychotic disorders also increase the risk of assorted dimensions of PE. Furthermore, it advocates the use of dimensional approaches when examining environmental exposures for PE given that environmental risks distribute differently across dimensions.

The Impact of Childhood Trauma on Developing Bipolar Disorder: Current Understanding and Ensuring Continued Progress

Childhood trauma (CT) has been repeatedly linked to earlier onset and greater severity of bipolar disorder (BD) in adulthood. However, such knowledge is mostly based on retrospective and cross-sectional studies in adults with BD. The first objective of this selective review is to characterize the short-term effects of CT in the development of BD by focusing on studies in young people. The second objective is to describe the longer-term consequences of CT by considering studies with adult participants. This review first outlines the most prominent hypotheses linking CT exposure and the onset of BD. Then, it summarizes the psychological and biological risk factors implicated in the development of BD, followed by a discussion of original studies that investigated the role of CT in young people with early-onset BD, youths at increased risk of developing BD, or young people with BD with a focus on subclinical and clinical outcome measures. The review considers additional biological and psychological factors associated with a negative impact of CT on the long-term course of BD in later adulthood. Finally, we discuss how the integration of information of CT can improve ongoing early identification of BD and mitigate severe clinical expression in later adulthood.

The Brief 10-Item Community Assessment of Psychic Experiences-Positive Scale (Brief CAPE-P10): Initial psychometric properties, gender measurement invariance and mean differences among Nigerian adolescents

AIM

The aim of this study was to evaluate the Community Assessment of Psychic Experiences-Positive Scale (CAPE-P) for its psychometric properties in terms of its reliability and validity, in addition to its factor structure and gender measurement invariance among Nigerian adolescents (n = 1336, M_age = 15.15).

METHODS

The sample consisted of 606 (45.4%) males, who completed the 20-items CAPE-P in addition to the Positive and Negative Suicide Ideation Inventory (PANSI), the Hospital Anxiety and Depression Scale (HADS) and the Rosenberg Self-Esteem Scale (RSES). We compared 11 a priori models of the CAPE-P with the aim of identifying the one with the best fit indices applying Confirmatory Factor Analysis (CFA). Gender measurement invariance was examined with nested multiple-group confirmatory factor analysis (MGCFA).

RESULTS

All the 11 a priori models had poor fit indices. An examination of the scale's 20 items revealed that 10 items had poor correlation with the overall scale. The remaining 10 items which we labelled as the Brief CAPE-P10 were subjected to CFA which yielded a 3-factor model (Bizarre Experiences-5 items, Delusional Ideation-3 items and Perceptual Anomalies-2 items) with satisfactory fit indices (CFI = 0.961, SRMR = 0.0376, RMSEA = 0.062/90% CI = 0.052-0.069). The validity and reliability of the Brief CAPE-P10 and its subscales were modestly satisfactory. MGCFA affirmed the configural, metric and scalar gender invariance of the 3-factor Brief CAPE-P10.

CONCLUSIONS

The Brief CAPE-P10 is a promising instrument for the evaluation of PLEs among Nigerian adolescents.

Genetic overlap between psychotic experiences in the community across age and with psychiatric disorders

This study explores the degree to which genetic influences on psychotic experiences are stable across adolescence and adulthood, and their overlap with psychiatric disorders. Genome-wide association results were obtained for adolescent psychotic experiences and negative symptom traits (N = 6297-10,098), schizotypy (N = 3967-4057) and positive psychotic experiences in adulthood (N = 116,787-117,794), schizophrenia (N = 150,064), bipolar disorder (N = 41,653), and depression (N = 173,005). Linkage disequilibrium score regression was used to estimate genetic correlations. Implicated genes from functional and gene-based analyses were compared. Mendelian randomization was performed on trait pairs with significant genetic correlations. Results indicated that subclinical auditory and visual hallucinations and delusions of persecution during adulthood were significantly genetically correlated with schizophrenia (rg = 0.27-0.67) and major depression (rg = 0.41-96) after correction for multiple testing. Auditory and visual subclinical hallucinations were highly genetically correlated (rg = 0.95). Cross-age genetic correlations for psychotic experiences were not significant. Gene mapping and association analyses revealed 14 possible genes associated with psychotic experiences that overlapped across age for psychotic experiences or between psychotic experiences and psychiatric disorders. Mendelian randomization indicated bidirectional associations between auditory and visual hallucinations in adults but did not support causal relationships between psychotic experiences and psychiatric disorders. These findings indicate that psychotic experiences in adulthood may be more linked genetically to schizophrenia and major depression than psychotic experiences in adolescence. Our study implicated specific genes that are associated with psychotic experiences across development, as well as genes shared between psychotic experiences and psychiatric disorders.

Validation of the Portuguese version of the Community Assessment of Psychic Experiences and characterization of psychotic experiences in a Brazilian sample

Objective:

We investigated: i) the reliability and validity of a Brazilian version of the Community Assessment of Psychic Experiences (CAPE), developed to detect and characterize psychotic experiences in the general population; and ii) the association between psychotic experiences, childhood adversity, and cannabis use in a population-based sample.

Methods:

We performed factorial analyses and generalized linear models with CAPE scores as the dependent variable in a sample composed of 217 first-episode psychosis patients, 104 unaffected biological siblings, and 319 non-psychotic population-based participants.

Results:

After removing seven items from its positive dimension and two items from its negative dimension, a 33-item Brazilian version of the CAPE showed acceptable adjustment indices (confirmatory fit index = 0.895; goodness of fit index = 0.822; parsimony goodness of fit index = 0.761; root mean square error of approximation [RMSEA] = 0.055, p [RMSEA ≤ 0.05] = 0.04) and internal consistency in all its dimensions (> 0.70). Childhood adversity was associated with higher scores in all three dimensions, as well as with total score. Lifetime cannabis use was associated with higher scores only in the positive dimension.

Conclusion:

The proposed Brazilian version of the CAPE corroborates the tridimensional approach for assessing psychosis-proneness, and the frequency and severity of psychotic manifestations are distributed as a spectrum in the general population.

Rural birth/upbringing and childhood adversities are associated with psychotic experiences in university students in China

BACKGROUND

Urbanicity has been reported to associate with an increased risk of psychotic experiences (PEs) in developed countries but less is known about the situation in developing countries. The present study aimed to investigate the effects of birth/upbringing place and other environmental factors on PEs in Chinese university students.

METHODS

A computer-assisted cross-sectional survey was conducted on 4620 second-year undergraduates, using a stratified cluster sampling. Birth places and residential mobility before 16 years old were recorded. PEs were measured using the subscales of psychoticism and paranoid ideation in the Symptom Checklist-90-R (SCL-90-R). Six questions extracted from the childhood section of the World Mental Health Composite International Diagnostic Interview (WMH-CIDI) were used to assess childhood trauma.

RESULTS

Generalized ordered logit model of multiple regression analysis revealed that participants with rural birth/upbringing (e.g. rural upbringing, on graded factor score of psychoticism and paranoid ideation [GFSPPI], 0 versus 1 & 2, odds ratio [OR] 1.409, 95% CI 1.219-1.628, p < 0.00001; 0 & 1 versus 2, OR 1.584, 95% CI 1.179-2.128, p < 0.00001) and those who reported childhood trauma (e.g. on GFSPPI, 0 versus 1 & 2, OR 1.737, 95% CI 1.498-2.014, p < 0.00001; 0 & 1 versus 2, OR 1.618, 95% CI 1.224-2.140, p < 0.00001) were apt to present more severe PEs. While upbringing places and childhood trauma affected both the presence and the severity of PEs, gender affected the presence or absence of PEs only (e.g. females, on GFSPPI, 0 versus 1 & 2, OR 1.887, 95% CI 1.631-2.183, p < 0.00001; 0 & 1 versus 2, OR 0.927, 95% CI 0.702-1.223, p = 0.593). Besides, the number of risk factors was associated with the severity of PEs in the cumulative odds logistic regression analysis (e.g. 3 risk factors versus 0 risk factor, on GFSPPI, OR 4.126, 95% CI 3.075-5.537, p < 0.00001).

CONCLUSIONS

Female, rural birth/upbringing and childhood trauma are risk factors of PEs in university students in China. The discrepancy in the findings between developed countries and China has important implications for urbanicity as a risk factor for PEs.

Genetic and environmental influences on the stability of psychotic experiences and negative symptoms in adolescence

BACKGROUND

Psychotic experiences (PEs) such as paranoia and hallucinations, and negative symptoms (NS) such as anhedonia and flat affect are common in adolescence. Psychotic experiences and negative symptoms (PENS) increase risk for later psychiatric outcomes, particularly when they persist. The extent to which genetic and environmental influences contribute to the stability of PENS in mid-to-late adolescence is unknown.

METHODS

Using the Specific Psychotic Experiences Questionnaire (SPEQ) twice across ~9 months in adolescence, N = 1,448 twin pairs [M = 16.32 (0.68)] reported experiences of paranoia, hallucinations, cognitive disorganization, grandiosity and anhedonia, and their parents reported on a range of NS. Individuals were split into low-scoring, decreasing, increasing and persistent groups for each subscale. Frequencies and mean differences in distress, depression traits and emotional problems were investigated across groups. Longitudinal structural equation modelling was used to estimate the aetiological components underlying the stability of PENS.

RESULTS

Phenotypic stability was moderate for all PENS (r = .59-.69). Persistent PENS across 9 months were associated with greater levels of distress (V = 0.15-0.46, for PEs only), depression traits (d = 0.47-1.67, except grandiosity) and emotional problems (d = 0.47-1.47, except grandiosity and anhedonia) at baseline compared to groups with transitory or low levels of PENS. At both ages PENS were heritable and influenced by shared and nonshared environment. Genetic influences contributed 38%-62% and shared environment contributed 13%-33% to the stability of PENS. Nonshared environment contributed 34%-41% (12% for parent-rated NS). There was strong overlap of genetic and shared environmental influences across time, and lower overlap for nonshared environment. Imperfect stability of PENS was at least partly due to nonshared environmental influences.

CONCLUSIONS

When adolescent PENS persist over time, they are often characterized by more distress, and higher levels of other psychopathology. Both genetic and environmental effects influence stability of PENS.

Is There Any Association Between Childhood Traumatic Experiences, Dissociation and Psychotic Symptoms in Schziophrenic Patients?

OBJECTIVE

The aim of this study was to investigate the rates childhood traumatic experiences (CTEs) of schizophrenia patients and to examine relationship between childhood traumatic experiences, dissociation and psychotic symptoms.

METHODS

One hundred schizophrenia patients who had 5 or 5 points below in Clinical Global Impression-Severity (CGI-S) and who were not in active psychotic episode and 50 healthy siblings who grew up in the same environment with the patients were included to the study. Structured Clinical Interview for DSM IV, Scale for the Assessment of Positive Symptoms, Scale for the Assessment of Negative Symptoms, Dissociative Experiences Scale (DES), CGI-S, Global Assessment of Functioning Scale and Childhood Trauma Questionnaire (CTQ-28) applied to the patients.

RESULTS

Childhood abuse subscales and DES scores were statistically higher in the patient group (p<0.001). We determined moderately significant positive correlation between CTQ-28 and DES. We determined moderately significant positive correlation between CTQ total scores and persecutory delusions, delusions of reference, ability to feel intimacy and closeness; relationship with friends and peers. Also, there was a significant positive correlation between persecutory delusions and CTQ-total, DES-total and all subscales of CTQ-28.

CONCLUSION

Clinicians should inquire about CTEs to develop comprehensive formulations and treatment plans among schizophrenia.

Evidence that the association of childhood trauma with psychosis and related psychopathology is not explained by gene-environment correlation: A monozygotic twin differences approach

BACKGROUND

Converging evidence supports childhood trauma as possible causal risk for psychosis and related psychopathology. However, studies have shown that baseline psychotic symptoms may actually increase risk for subsequent victimization, suggesting that exposure to CT is not random but may result from pre-existing vulnerability. Therefore, studies testing whether the association between CT and psychopathology persists when accounting for gene-environment correlation are much needed.

METHODS

A monozygotic (MZ) twin differences approach was used to examine whether differences in CT exposure among MZ twin pairs would be associated with MZ differences in symptoms. As MZ twins are genetically identical, within-pair correlations between CT exposure and psychopathology rule out the possibility that the association is solely attributable to gene-environment correlation. 266 monozygotic twins (133 pairs) from a larger general population study were available for analysis.

RESULTS

CT was associated with symptoms of psychosis (B = 0.62; SE = 0.08, p < .001) and overall psychopathology (B = 43.13; SE = 6.27; p < .001). There were measurable differences within pairs in CT exposure and symptoms, allowing for meaningful within-pair differences. Within-pair differences in CT exposure were associated with within-pair differences in symptoms of psychosis (B = 0.35; SE = 0.16; p = .024), as well as with overall psychopathology (B = 29.22; SE = 12.24; p = .018), anxiety (B = 0.65; SE = 0.21; p = .002) and depression (B = 0.37; SE = 0.18; p = .043).

CONCLUSION

While it is not unlikely that pre-existing vulnerability may increase the risk for traumatic exposures, such gene-environment correlation does not explain away the association between CT and psychopathology. The present findings thus suggest that at least part of the association between CT and psychopathology may be causal.

A systematic review of genome-wide research on psychotic experiences and negative symptom traits: new revelations and implications for psychiatry

We present a systematic review of genome-wide research on psychotic experience and negative symptom (PENS) traits in the community. We integrate these new findings, most of which have emerged over the last four years, with more established behaviour genetic and epidemiological research. The review includes the first genome-wide association studies of PENS, including a recent meta-analysis, and the first SNP heritability estimates. Sample sizes of <10 000 participants mean that no genome-wide significant variants have yet been replicated. Importantly, however, in the most recent and well-powered studies, polygenic risk score prediction and linkage disequilibrium (LD) score regression analyses show that all types of PENS share genetic influences with diagnosed schizophrenia and that negative symptom traits also share genetic influences with major depression. These genetic findings corroborate other evidence in supporting a link between PENS in the community and psychiatric conditions. Beyond the systematic review, we highlight recent work on gene-environment correlation, which appears to be a relevant process for psychotic experiences. Genes that influence risk factors such as tobacco use and stressful life events are likely to be harbouring 'hits' that also influence PENS. We argue for the acceptance of PENS within the mainstream, as heritable traits in the same vein as other sub-clinical psychopathology and personality styles such as neuroticism. While acknowledging some mixed findings, new evidence shows genetic overlap between PENS and psychiatric conditions. In sum, normal variations in adolescent and adult thinking styles, such as feeling paranoid, are heritable and show genetic associations with schizophrenia and major depression.

Genome-wide analysis of adolescent psychotic-like experiences shows genetic overlap with psychiatric disorders

This study aimed to test for overlap in genetic influences between psychotic-like experience traits shown by adolescents in the community, and clinically-recognized psychiatric disorders in adulthood, specifically schizophrenia, bipolar disorder, and major depression. The full spectra of psychotic-like experience domains, both in terms of their severity and type (positive, cognitive, and negative), were assessed using self- and parent-ratings in three European community samples aged 15-19 years (Final N incl. siblings = 6,297-10,098). A mega-genome-wide association study (mega-GWAS) for each psychotic-like experience domain was performed. Single nucleotide polymorphism (SNP)-heritability of each psychotic-like experience domain was estimated using genomic-relatedness-based restricted maximum-likelihood (GREML) and linkage disequilibrium- (LD-) score regression. Genetic overlap between specific psychotic-like experience domains and schizophrenia, bipolar disorder, and major depression was assessed using polygenic risk score (PRS) and LD-score regression. GREML returned SNP-heritability estimates of 3-9% for psychotic-like experience trait domains, with higher estimates for less skewed traits (Anhedonia, Cognitive Disorganization) than for more skewed traits (Paranoia and Hallucinations, Parent-rated Negative Symptoms). Mega-GWAS analysis identified one genome-wide significant association for Anhedonia within IDO2 but which did not replicate in an independent sample. PRS analysis revealed that the schizophrenia PRS significantly predicted all adolescent psychotic-like experience trait domains (Paranoia and Hallucinations only in non-zero scorers). The major depression PRS significantly predicted Anhedonia and Parent-rated Negative Symptoms in adolescence. Psychotic-like experiences during adolescence in the community show additive genetic effects and partly share genetic influences with clinically-recognized psychiatric disorders, specifically schizophrenia and major depression.

A twin study exploring the association between childhood emotional and behaviour problems and specific psychotic experiences in a community sample of adolescents

BACKGROUND

Childhood emotional and behaviour problems are antecedents for later psychopathology. This study investigated genetic and environmental influences shaping the longitudinal association between childhood emotional and behaviour problems and specific PEs.

METHOD

In a community-based twin sample, parents reported on emotional and behaviour problems when twins were ages 7 and 12 years. At age 16 years, specific PEs were measured using self-reports and parent reports. Structural equation model-fitting was conducted.

RESULTS

Childhood emotional and behaviour problems were significantly associated with paranoia, cognitive disorganisation and parent-rated negative symptoms in adolescence (mean r = .15-.38), and to a lesser extent with hallucinations, grandiosity and anhedonia (mean r = .04-.12). Genetic influences on childhood emotional and behaviour problems explained significant proportions of variance in adolescent paranoia (4%), cognitive disorganisation (8%) and parent-rated negative symptoms (3%). Unique environmental influences on childhood emotional and behaviour problems explained ≤1% of variance in PEs. Common environmental influences were only relevant for the relationship between childhood emotional and behaviour problems and parent-rated negative symptoms (explaining 28% of variance) and are partly due to correlated rater effects.

CONCLUSIONS

Childhood emotional and behaviour problems are significantly, if weakly, associated with adolescent PEs. These associations are driven in part by common genetic influences underlying both emotional and behaviour problems and PEs. However, psychotic experiences in adolescence are largely influenced by genetic and environmental factors that are independent of general childhood emotional and behaviour problems, suggesting they are not merely an extension of childhood emotional and behaviour problems.

Childhood victimization and inflammation in young adulthood: A genetically sensitive cohort study

OBJECTIVE

Childhood victimization is an important risk factor for later immune-related disorders. Previous evidence has demonstrated that childhood victimization is associated with elevated levels of inflammation biomarkers measured decades after exposure. However, it is unclear whether this association is (1) already detectable in young people, (2) different in males and females, and (3) confounded by genetic liability to inflammation. Here we sought to address these questions.

METHOD

Participants were 2232 children followed from birth to age 18years as part of the Environmental Risk (E-Risk) Longitudinal Twin Study. Childhood victimization was measured prospectively from birth to age 12years. Inflammation was measured through C-reactive protein (CRP) levels in dried blood spots at age 18years. Latent genetic liability for high inflammation levels was assessed through a twin-based method.

RESULTS

Greater exposure to childhood victimization was associated with higher CRP levels at age 18 (serum-equivalent means were 0.65 in non-victimized Study members, 0.74 in those exposed to one victimization type, and 0.81 in those exposed to poly-victimization; p=0.018). However, this association was driven by a significant association in females (serum-equivalent means were 0.75 in non-victimized females, 0.87 in those exposed to one type of victimization, and 1.19 in those exposed to poly-victimization; p=0.010), while no significant association was observed in males (p=0.19). Victimized females showed elevated CRP levels independent of latent genetic influence, as well as childhood socioeconomic status, and waist-hip ratio and body temperature at the time of CRP assessment.

CONCLUSION

Childhood victimization is associated with elevated CRP levels in young women, independent of latent genetic influences and other key risk factors. These results strengthen causal inference about the effects of childhood victimization on inflammation levels in females by accounting for potential genetic confounding.

Is sensitivity to daily stress predictive of onset or persistence of psychopathology?

PURPOSE

The aim of the current study was to replicate findings in adults indicating that higher sensitivity to stressful events is predictive of both onset and persistence of psychopathological symptoms in a sample of adolescents and young adults. In addition, we tested the hypothesis that sensitivity to mild stressors in particular is predictive of the developmental course of psychopathology.

METHODS

We analyzed experience sampling and questionnaire data collected at baseline and one-year follow-up of 445 adolescent and young adult twins and non-twin siblings (age range: 15-34). Linear multilevel regression was used for the replication analyses. To test if affective sensitivity to mild stressors in particular was associated with follow-up symptoms, we used a categorical approach adding variables on affective sensitivity to mild, moderate and severe daily stressors to the model.

RESULTS

Linear analyses showed that emotional stress reactivity was not associated with onset (β=.02; P=.56) or persistence (β=-.01; P=.78) of symptoms. There was a significant effect of baseline symptom score (β=.53; P<.001) and average negative affect (NA: β=.19; P<.001) on follow-up symptoms. Using the categorical approach, we found that affective sensitivity to mild (β=.25; P<.001), but not moderate (β=-.03; P=.65) or severe (β=-.06; P=.42), stressors was associated with symptom persistence one year later.

DISCUSSION

We were unable to replicate previous findings relating stress sensitivity linearly to symptom onset or persistence in a younger sample. Whereas sensitivity to more severe stressors may reflect adaptive coping, high sensitivity to the mildest of daily stressors may indicate an increased risk for psychopathology.

The association between childhood adversities and subsequent first onset of psychotic experiences: a cross-national analysis of 23 998 respondents from 17 countries

BACKGROUND

Although there is robust evidence linking childhood adversities (CAs) and an increased risk for psychotic experiences (PEs), little is known about whether these associations vary across the life-course and whether mental disorders that emerge prior to PEs explain these associations.

METHOD

We assessed CAs, PEs and DSM-IV mental disorders in 23 998 adults in the WHO World Mental Health Surveys. Discrete-time survival analysis was used to investigate the associations between CAs and PEs, and the influence of mental disorders on these associations using multivariate logistic models.

RESULTS

Exposure to CAs was common, and those who experienced any CAs had increased odds of later PEs [odds ratio (OR) 2.3, 95% confidence interval (CI) 1.9-2.6]. CAs reflecting maladaptive family functioning (MFF), including abuse, neglect, and parent maladjustment, exhibited the strongest associations with PE onset in all life-course stages. Sexual abuse exhibited a strong association with PE onset during childhood (OR 8.5, 95% CI 3.6-20.2), whereas Other CA types were associated with PE onset in adolescence. Associations of other CAs with PEs disappeared in adolescence after adjustment for prior-onset mental disorders. The population attributable risk proportion (PARP) for PEs associated with all CAs was 31% (24% for MFF).

CONCLUSIONS

Exposure to CAs is associated with PE onset throughout the life-course, although sexual abuse is most strongly associated with childhood-onset PEs. The presence of mental disorders prior to the onset of PEs does not fully explain these associations. The large PARPs suggest that preventing CAs could lead to a meaningful reduction in PEs in the population.

Psychotic-like experiences, trauma and related risk factors among "left-behind" children in China

BACKGROUND

Large scale migration of workers due to wage differences across regions of China has separated millions of children, called "left-behind children" from their parents. Psychotic-like experiences (PLEs) are thought to be associated with childhood deprivation and may predict later psychotic disorders but have not been studied in this potentially vulnerable population.

METHODS

Data were collected from representative samples of students in thirteen middle schools in the Xiangxi region and Changsha city of Hunan province (N=6623), of whom 1360 (21.3%) were "left-behind" children. Children were surveyed with the positive frequency subscales of the Community Assessment of Psychic Experiences and the Trauma History Questionnaire child version.

RESULTS

More "left-behind" children reported experiencing PLEs than others. They also scored higher on the overall frequency of PLEs, severity of childhood trauma, and the subjectively perceived psychological impact of trauma both at the time of the events and at present. Compared with "left-behind" children raised by a parent or by grandparents, those raised by others reported suffering more severe impact both at the time of the events and at present. Among "left-behind" children trauma history was the most important correlate of PLEs followed by Han ethnicity, older age, and not having a stable family income.

CONCLUSION

"Left-behind" children are at higher risk for PLEs and suffer more traumatic events than other Chinese children. Interventions that reduce trauma risk and improve relationships with caregivers may be helpful, especially for older "left-behind" children.

Toward a unified theory of childhood trauma and psychosis: A comprehensive review of epidemiological, clinical, neuropsychological and biological findings

There is a growing body of research focused on the relationship between childhood trauma and the risk of developing psychosis. Numerous studies, including many large-scale population-based studies, controlling for possible mediating variables, provide persuasive evidence of a dose-response association and are indicative of a causal relationship. Existing evidence supports the specificity model, showing differential associations between particular adversities and clinical symptoms, with cumulative adversity causing less favorable clinical and functional outcomes in psychotic patients. To date, several psychological and biological models have been proposed to search for underlying developmental trajectories leading to the onset of psychosis, influencing psychopathological manifestation and negative functional outcomes due to a history of childhood trauma. In this article, we provide a unified review on the relationship between childhood trauma and psychosis by integrating results of epidemiological, clinical, neuropsychological and biological studies. The question whether psychosis with a positive history of childhood trauma should be considered as a new psychotic phenotype, requiring specific therapeutic interventions, warrants further investigation.

Developmental course of subclinical positive and negative psychotic symptoms and their associations with genetic risk status and impairment

The proneness-persistence-impairment (PPI) model states that psychotic experiences are more likely to lead to impairment if their expression becomes persistent. Higher genetic risk for psychosis is known to affect proneness and persistence of subclinical positive symptoms. Less is known about potential effects of genetic risk on the course of subclinical negative symptoms, impairment, and their subsequent associations. The current study examined these issues in a large sample (n=1131), consisting of individuals with higher genetic risk (siblings of patients with psychotic disorders, n=703) and lower genetic risk (controls without a family member with lifetime psychosis, n=428). Psychotic experiences were assessed with the CAPE questionnaire, at two time points three years apart. Participants were allocated to one of four groups representing developmental course: stable low, decreasing, increasing or persisting subclinical positive/negative symptoms. Lifetime clinical psychosis was an exclusion criterion at baseline. Higher genetic risk status was found to be associated with a persisting course of both subclinical positive and negative symptoms, symptom-related distress and functional impairment. There is no evidence for an effect of genetic risk status on the association between developmental course and impairment. The results of the current study underline the importance of assessing psychotic experiences in the context of genetic risk, multidimensional and over time. Additionally, the current findings both underscore and contribute to the PPI model: psychotic experiences are more likely to lead to impairment if their expression becomes persistent, both in individuals with higher and lower genetic risk for psychosis.

Psychosis as a transdiagnostic and extended phenotype in the general population

A large body of research indicates that weak expressions of positive psychotic symptoms ("psychotic experiences") can be measured in the general population, and likely represent the behavioural manifestation of distributed multifactorial (genetic and non-genetic) risk for psychosis. Psychotic experiences are a transdiagnostic phenomenon: the majority of individuals with these experiences have a diagnosis of non-psychotic disorder, particularly common mental disorder, in which psychotic experiences predict greater illness severity and poorer treatment response. Some of the people with common mental disorder and psychotic experiences will present to mental health services meeting criteria for "clinical high risk". Treatment of the transdiagnostic dimension of psychosis in individuals with common mental disorder who meet "clinical high risk" criteria thus may improve outcome (which cannot be interpreted as prevention of "schizophrenia"). Subthreshold psychotic experiences are transitory in about 80% of individuals, while around 20% go on to develop persistent psychotic experiences and 7% a psychotic disorder, with an annual transition rate of 0.5-1%. Persistence is associated, on the one hand, with environmental exposures, particularly childhood trauma, and, on the other, with network-type dynamic interactions between psychotic experiences themselves (e.g., interactions between hallucinatory experiences and delusional ideation) and between symptom dimensions (e.g., interactions between affective symptoms and psychotic experiences, or interactions between subthreshold negative symptoms and psychotic experiences). The study of psychotic experiences is helping to elucidate the mechanisms by which environmental and genetic influences shape the transdiagnostic expression of psychosis proneness, that is mostly transitory but may first become persistent over time and eventually give rise to transition to a psychotic disorder.

Disturbed Experience of Self: Psychometric Analysis of the Self-Experience Lifetime Frequency Scale (SELF)

BACKGROUND

Schizophrenia is characterized by positive and negative symptoms, but recently anomalous self-experiences, e.g. exaggerated self-consciousness (hyperreflectivity), receive more attention as an important symptom domain in schizophrenia patients. The semi-structured interview, the Examination of Anomalous Self-Experience (EASE) [Psychopathology 2005;38:236-258], examines experiences of a disturbed sense of self in a sophisticated but time-consuming manner. Therefore, we proposed the Self-Experience Lifetime Frequency scale (SELF), an instrument intended to screen for self-disturbance phenomena. Here we compared scores of patients, their siblings and healthy controls on the SELF. Methods and Sampling: The SELF is composed of a validated screener for symptoms of depersonalization complemented by questions covering several other domains of self-disturbance. A total of 426 patients with a psychotic disorder, 526 of their unaffected siblings, and 297 healthy controls completed the SELF. Patients' scores on the 12 items of the SELF were subjected to an explorative principal axis factor analysis (PAF); composite scores on factor components were compared between the three participant groups.

RESULTS

The PAF revealed two components, explaining 43.9 and 9.5% of variance, respectively. The first component represents a disturbance of self-awareness; the second component reflects (milder forms of) diminished self-affection or depersonalization. The two components of the SELF revealed good internal consistency (component 1, α = 0.88; component 2, α = 0.79; x03C1; = 0.85). Patients showed significantly higher scores on both factor components in comparison with both siblings and controls. No significant differences were found between siblings and controls.

CONCLUSIONS

The findings of the current study suggest that the SELF comprises two components of self-disturbance. Patients reported more (severe) symptoms of self-disturbance on both components, suggesting that it is feasible to screen for self-disturbance phenomena in patients with psychotic disorders with the SELF. Screening for symptoms of self-disturbance is important since these symptoms are associated with suffering and, moreover, these phenomena may mark the transition from intact to aberrant reality testing.

Psychotic-like experiences and associated socio-demographic factors among adolescents in China

OBJECTIVE

Adolescents with persistent psychotic-like experiences (PLEs) may be at high risk for later development of psychoses. Exploring early age risk factors for PLEs may provide useful information for prevention of mental disorders and improvement of mental health.

METHOD

A total of 5427 adolescents (aged between 10 and 16) participated in a cross-sectional survey, with social and demographic information collected. The Positive Subscale of Community Assessment of Psychic Experiences (CAPE) was used to measure PLEs, and the CAPE Depressive and Negative Subscales were used to examine depressive and negative experiences. The Trauma History Questionnaire (child version) was used to assess experiences of previous traumatic events.

RESULTS

In our study, 95.7% of the adolescents reported more than one episode of PLEs, while 17.2% reported "nearly always" having PLEs. High positive correlations were shown both between frequency scores among experiences of three dimensions (PLEs, depressive and negative experiences), and between frequency and distress scores. Factors associated with a higher risk for more frequent and distressing PLEs include: urban setting, family history of psychiatric illnesses, and higher impact from previous traumatic events at present.

CONCLUSIONS

Episodes of PLEs are common in Chinese adolescents, however only a small proportion have persistent PLEs, with worsening distress as the frequency increased. PLEs shared similar environmental and genetic risk factors not only with the clinical phenotypes, which is consistent with the continuity model of PLEs, but also with depressive and negative experiences, which may imply etiologic relation between different dimensions of psychosis at the subclinical level.

Mild psychotic experiences among ethnic minority and majority adolescents and the role of ethnic density

PURPOSE

Despite evidence of the increased risk of psychotic disorders among ethnic minority adults, little is known about the effect of ethnic minority status to mild psychotic experiences among adolescents. This study investigated mild psychotic experiences in ethnic minority and majority adolescents in a Dutch representative general population sample, and tested the ethnic density effect in the classroom.

METHODS

The CAPE was used to assess mild psychotic experiences among Dutch (n = 3,606) and non-Western ethnic minority pupils (n = 769).

RESULTS

Ethnic minority adolescents showed higher levels of grandiosity and delusions than their ethnic majority peers, whereas no differences were found for hallucinations, paranormal beliefs and paranoia between both groups of adolescents. The ethnic density effect was partly confirmed for the ethnic majority: a decrease of ethnic majority pupils in class increased their feelings of paranoia.

CONCLUSIONS

Because only some dimensions of mild psychotic experiences were affected by ethnic minority status or the interaction between ethnic minority status and ethnic class composition, our findings emphasize that mild psychotic experiences are multifactorial in origin, with different underlying processes.

The impact of childhood adversity on the persistence of psychotic symptoms: a systematic review and meta-analysis

BACKGROUND

Evidence suggests that childhood adversity is associated with the development of psychotic experiences (PE), psychotic symptoms and disorders. However, less is known regarding the impact of early adversity on the persistence of PE and clinically relevant psychosis. Thus we conducted a systematic review of the association between childhood adversity and the course of PE and symptoms over time.

METHOD

A systematic search of Medline, EMBASE and PsychINFO databases was undertaken to identify articles published between January 1956 and November 2014. We included studies conducted on general population samples, individuals at ultra-high risk (UHR) of psychosis, and patients with full-blown psychotic disorders. A meta-analysis was performed on a subgroup.

RESULTS

A total of 20 studies were included. Of these, 17 reported positive associations between exposure to overall or specific subtypes of childhood adversity and persistence of PE or clinically relevant psychotic symptoms. A meta-analysis of nine studies yielded a weighted odds ratio of 1.76 [95% confidence interval (CI) 1.19-2.32, p < 0.001] for general population studies and 1.55 (95% CI 0.32-2.77, p = 0.007) for studies conducted using clinical populations.

CONCLUSIONS

The available evidence is limited but tentatively suggests that reported exposure to adverse events in childhood is associated with persistence of PE and clinically relevant psychotic symptoms. This partially strengthens the case for addressing the consequences of early adversity in individuals presenting with psychotic phenomena to improve long-term outcomes. However, the heterogeneity of studies was high which urges caution in interpreting the results and highlights the need for more methodologically robust studies.

Stress sensitivity mediates the relationship between traumatic life events and attenuated positive psychotic symptoms differentially by gender in a college population sample

The purpose of this study was to investigate whether stress sensitivity mediates the relationship between traumatic life events and total attenuated positive psychotic symptoms, as well as the relationship between traumatic life events and endorsement of 8 or more attenuated positive psychotic symptoms as distressing (a threshold that has been associated with higher risk for psychosis in clinical groups). Participants (n = 671, aged 17-35, 29% male) were college students who were administered the Prodromal Questionnaire, the Perceived Stress Scale and the Life Events Checklist. Bootstrapping results indicated that stress sensitivity significantly mediated the relationships between traumatic life events and the number of attenuated positive psychotic symptoms endorsed and between traumatic life events and those who endorsed 8 or more distressing attenuated positive psychotic symptoms. Stratified gender analyses indicated the findings were specific to females. Results suggest that stress sensitivity may represent a specific vulnerability factor for risk of attenuated psychotic symptoms in those previously exposed to traumatic life events and that this liability appears stronger in females.

Prevalence of psychotic-like experiences in young adults with social anxiety disorder and correlation with affective dysregulation

Social anxiety disorder (SAD) is associated with psychotic-like experiences (PLEs) and is a frequent diagnosis in the prodromal phases of psychosis. We investigated whether psychopathological factors could discriminate which subjects with SAD are more likely to develop PLEs. A sample of 128 young adults with SAD was split into two subsamples according to the presence of clinically relevant PLEs. Correlations between PLEs and other psychopathological markers were explored. The SAD with PLEs group showed higher level of anxiety, depression, and intolerance of uncertainty (IU) compared with the SAD without PLEs group. A limitation of this study is that the cross-sectional design precluded the analysis of causality. In our sample, the presence of PLEs is related to higher levels of depression, anxiety, and IU. The current findings are consistent with hypotheses suggesting that cognitive disturbances, together with social anxiety, may result in PLEs.

From epidemiology to daily life: linking daily life stress reactivity to persistence of psychotic experiences in a longitudinal general population study

Subclinical psychotic experiences at the level of the general population are common, forming an extended psychosis phenotype with clinical psychosis. Persistence of subclinical experiences is associated with transition to later mental disorder. Increased daily life stress reactivity is considered an endophenotype for psychotic disorders. We examined, in a longitudinal framework, whether baseline momentary assessment markers of stress reactivity would predict persistence of subclinical psychotic experiences over time. In a general population sample of female twins (N = 566), the Experience Sampling Method (ESM; repetitive random sampling of momentary emotions, psychotic experiences and context) was used to assess (emotional and psychotic) daily life stress reactivity. Persistence of subclinical psychotic experiences was based on the Community Assessment of Psychic Experiences (CAPE), assessed three times over 14 months post-baseline. It was investigated whether baseline daily life emotional and psychotic stress reactivity predicted persistence of psychotic experiences over time. Higher levels of emotional stress reactivity (a decrease in positive and an increase in negative affect in response to stress), and increased psychotic reactivity to daily stress was found in individuals with persistent psychotic experiences over time compared to individuals with transient psychotic experiences. The results suggest that markers of daily life stress reactivity may predict “macro-level” persistence of normally transient expression of psychotic liability over time. Linking daily life markers of altered reactivity in terms of emotions and psychotic experiences to longitudinal persistence of psychotic experiences, associated with increased risk of transition to overt mental disorder, may contribute to earlier and more accurate diagnosis of risk.

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

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

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

[Trauma and psychosis--part 2. On the association of early childhood maltreatment and risk of psychosis in general population]

Any association of early childhood maltreatment and later risk of psychosis may be favourably investigated by epidemiological studies in the general population. Primary outcome variable in these studies is the prevalence of subclinical psychotic symptoms (hallucinations, delusions) in early trauma-exposed groups compared to control groups without any significant trauma in childhood. A systematic literature search underlines a significant association of early childhood trauma and later non-clinical psychotic symptoms in representative samples of the general population both during childhood, adolescence and adulthood. Important questions deal with the issues, which psychological, psychosocial and neurobiological mechanisms may mediate the risk of early trauma in respect of later psychotic symptoms on the one side, and which factors may determine the transition from non-clinical psychotic symptoms to major psychotic disorders cared for within mental health services. Both theoretical models and first data derived from empirical studies will be presented.

Early trauma and familial risk in the development of the extended psychosis phenotype in adolescence

OBJECTIVE

Both genetic and environmental factors are thought to play a role in the development of psychotic outcomes; however, their respective contributions over time, including possible developmental interactions, remain largely unknown.

METHOD

The contribution of parental general and psychotic psychopathology as proxies of genetic risk to the development of subthreshold psychosis and its hypothesized interaction with childhood trauma were studied in a general population sample of 2230 adolescents, followed from age 10-16 years. Outcome measures were: i) level of psychotic experiences at age 16 years and ii) persistence of such experiences over the total follow-up period.

RESULTS

General parental psychopathology was associated with CAPE score (OR = 1.08; P < 0.043 for highest quintile) and suggestively predicted psychosis persistence (OR, 1.16; P < 0.072). Psychotic parental psychopathology was suggestively associated with CAPE score (OR, 2.25; P < 0.063 for highest quintile), predicted membership of the Persistent group (OR, 3.72; P < 0.039) and suggestively predicted membership of the Decreasing group (OR 2.04; P < 0.051). Childhood trauma was associated with CAPE score and with all developmental trajectories of subclinical psychosis. No evidence was found for an interaction between trauma and parental psychopathology.

CONCLUSION

The development and persistence of subthreshold psychotic symptoms may be conditional on non-interacting proxy genetic and environmental influences.

Childhood adversity and psychosis: Examining whether the association is due to genetic confounding using a monozygotic twin differences approach

Purpose

To test whether the association between childhood adversity and positive and negative psychotic experiences is due to genetic confounding.

Method

Childhood adversity and psychotic experiences were assessed in an ongoing sample of 226 twins from the general population. A monozygotic (MZ) twin differences approach was used to assess possible genetic confounding.

Results

In the whole sample, childhood adversity was significantly associated with positive (β = 45; SE = 0.16; P = 0.008) and negative psychotic experiences (β = 0.77; SE = 0.18; P < 0.01). Within-pair MZ twin differences in exposure to childhood adversity were significantly associated with differences in positive (β = 71; SE = 0.29; P = 0.016) and negative psychotic experiences (β = 98; SE = 0.38; P = 0.014) in a subsample of 85 MZ twin pairs.

Conclusions

Individuals exposed to childhood adversity are more likely to report psychotic experiences. Furthermore, our findings indicate that this association is not due to genetic confounding.