The association between neighborhood-level social fragmentation and distressing psychotic-like experiences in early adolescence: the moderating role of close friends.

BACKGROUND: Early exposure to neighborhood social fragmentation has been shown to be associated with schizophrenia. The impact of social fragmentation and friendships on distressing psychotic-like experiences (PLE) remains unknown. We investigate the relationships between neighborhood social fragmentation, number of friends, and distressing PLE among early adolescents. METHODS: Data were collected from the Adolescent Brain Cognitive Development Study. Generalized linear mixed models tested associations between social fragmentation and distressing PLE, as well as the moderating role of the number of total and close friends. RESULTS: Participants included 11 133 adolescents aged 9 to 10, with 52.3% being males. Greater neighborhood social fragmentation was associated with higher levels of distressing PLE (adjusted ß = 0.05; 95% CI: 0.01-0.09). The number of close but not total friends significantly interacted with social fragmentation to predict distressing PLE (adjusted ß = -0.02; 95% CI: -0.04 to <-0.01). Among those with fewer close friends, the association between neighborhood social fragmentation and distressing PLE was significant (adjusted ß = 0.07; 95% CI: 0.03-0.11). However, among those with more close friends, the association was non-significant (adjusted ß = 0.03; 95% CI: -0.01 to 0.07). CONCLUSIONS: Greater neighborhood social fragmentation is associated with higher levels of distressing PLE, particularly among those with fewer close friends. Further research is needed to disentangle aspects of the interaction between neighborhood characteristics and the quality of social interactions that may contribute to psychosis, which would have implications for developing effective interventions at the individual and community levels.

Social influences on the relationship between dissociation and psychotic-like experiences.

BACKGROUND: Shame is experienced as a threat to social self, and so activates threat-protective responses. There is evidence that shame has trauma-like characteristics, suggesting it can be understood within the same conceptual framework as trauma and dissociation. Evidence for causal links among trauma, dissociation, and psychosis thus warrant the investigation of how shame may influence causal mechanisms for psychosis symptoms. METHODS: This study tested the interaction between dissociation and shame, specifically external shame (feeling shamed by others), in predicting psychotic-like experiences (PLEs) six months later in a general population sample (N = 314). It also tested if social safeness moderates these effects. A longitudinal, online questionnaire design tested a moderation model (dissociation-shame) and a moderated moderation model (adding social safeness), using multiple regressions with bootstrap procedures. RESULTS: Although there was no direct effect of dissociation on PLEs six months later, there was a significant interaction effect with shame, controlling for PLEs at baseline. There were complex patterns in the directions of effects: For high-shame-scorers, higher dissociation predicted higher PLE scores, but for low-shame-scorers, higher dissociation predicted lower PLE scores. Social safeness was found to significantly moderate these interaction effects, which were unexpectedly more pronounced in the context of higher social safeness. CONCLUSIONS: The results demonstrate evidence for an interaction between dissociation and shame on its impact on PLEs, which manifests particularly for those experiencing higher social safeness. This suggests a potential role of social mechanisms in both the etiology and treatment of psychosis, which warrants further testing in clinical populations.

DNA methylation at birth and lateral ventricular volume in childhood: a neuroimaging epigenetics study.

BACKGROUND: Lateral ventricular volume (LVV) enlargement has been repeatedly linked to schizophrenia; yet, what biological factors shape LVV during early development remain unclear. DNA methylation (DNAm), an essential process for neurodevelopment that is altered in schizophrenia, is a key molecular system of interest. METHODS: In this study, we conducted the first epigenome-wide association study of neonatal DNAm in cord blood with LVV in childhood (measured using T1-weighted brain scans at 10 years), based on data from a large population-based birth cohort, the Generation R Study (N = 840). Employing both probe-level and methylation profile score (MPS) approaches, we further examined whether epigenetic modifications identified at birth in cord blood are: (a) also observed cross-sectionally in childhood using peripheral blood DNAm at age of 10 years (Generation R, N = 370) and (b) prospectively associated with LVV measured in young adulthood in an all-male sample from the Avon Longitudinal Study of Parents and Children (ALSPAC, N = 114). RESULTS: At birth, DNAm levels at four CpGs (annotated to potassium channel tetramerization domain containing 3, KCTD3; SHH signaling and ciliogenesis regulator, SDCCAG8; glutaredoxin, GLRX) prospectively associated with childhood LVV after genome-wide correction; these genes have been implicated in brain development and psychiatric traits including schizophrenia. An MPS capturing a broader epigenetic profile of LVV - but not individual top hits - showed significant cross-sectional associations with LVV in childhood in Generation R and prospectively associated with LVV in early adulthood within ALSPAC. CONCLUSIONS: This study finds suggestive evidence that DNAm at birth prospectively associates with LVV at different life stages, albeit with small effect sizes. The prediction of MPS on LVV in a childhood sample and an independent male adult sample further underscores the stability and reproducibility of DNAm as a potential marker for LVV. Future studies with larger samples and comparable time points across development are needed to further elucidate how DNAm associates with this clinically relevant brain structure and risk for neuropsychiatric disorders, and what factors explain the identified DNAm profile of LVV at birth.

Age-related differences in the impact of resilience on mental health outcomes during the COVID-19 pandemic in Hong Kong.

OBJECTIVE: This study investigated changes in mental health in Hong Kong over two years and examined the role of resilience and age in mitigating the negative effects of public health emergencies, particularly the COVID-19 pandemic. METHODS: Complete data of interest from two telephone surveys conducted in 2020 (n = 1182) and 2021 (n = 1108) were analysed. Participants self-reported depressive and anxiety symptoms using the Patient Health Questionnaire 4-item version (PHQ), psychotic-like experiences (PLEs) using three items from the Prodromal Questionnaire Brief (PQB), and resilience using the Connor-Davidson Resilience Scale 2-item version (CD-RISC-2). RESULTS: We observed an increase in the percentage of participants with high depressive and anxiety symptoms and PLEs from 1.6% to 6.5% between 2020 and 2021. The likelihood of having high depressive and anxiety symptoms or PLEs depended on resilience and age, with no significant between-year differences. Resilience and age interaction effects were significant when comparing the high PHQ-high PQB group to the low PHQ-low PQB group only in 2021 but not in 2020. CONCLUSIONS: This study provides valuable insights into the impact of the COVID-19 pandemic on mental health in Hong Kong, emphasising the age-dependent nature of resilience in mitigating negative effects. Future research should explore the mechanisms by which resilience promotes mental health and well-being and identify ways to enhance resilience among older individuals during public health crises.

Resilience buffers the association between psychotic-like experiences and suicide risk: a prospective study from a non-clinical sample.

BACKGROUND: Several studies have reported that psychotic-like experiences are associated with low levels of resilience and increased suicide risk. However, it remains unknown as to whether resilience mediates or moderates the association between psychotic-like experiences and suicide risk. Therefore, in this study, we aimed to explore the moderating and mediating effect of resilience in the association between psychotic-like experiences and suicide risk. METHODS: A total of 1100 non-clinical, young adults (aged 18 - 35 years) with a negative history of psychiatric treatment were enrolled. Participants were recruited by the snowball sampling methodology through advertisements posted in the online platform. They were followed-up for about 7 months. Variables of interest were recorded using self-reports. Psychopathological assessment was conducted using the Prodromal Questionnaire-16, the Patient Health Questionnaire-9, the Generalized Anxiety Disorder-7, the Traumatic Experience Checklist, the Childhood Experience of Care and Abuse Questionnaire, the Cannabis Problems Questionnaire, the Connor-Davidson Resilience Scale-10, and the Mini-International Neuropsychiatric Interview. The STROBE statement guidelines were followed. RESULTS: The moderation analysis revealed that higher levels of psychotic-like experiences and related distress at baseline were associated with significantly higher suicide risk at the follow-up after adjustment for baseline sociodemographic characteristics, depressive and anxiety symptoms, a history of childhood trauma, and problematic cannabis use. The interaction between follow-up resilience and distress related to baseline psychotic-like experiences was significantly and negatively associated with suicide risk at the follow-up. Specifically, the correlation between the level of distress related to psychotic-like experiences and suicide risk was significant and positive only in participants with lower levels of resilience. This interaction did not reach statistical significance for the baseline level of psychotic-like experiences. No significant mediating effect of the follow-up resilience level in the association between baseline psychotic-like experiences and the follow-up suicide risk was found. CONCLUSIONS: Findings from the present study indicate that resilience might protect against suicide risk in people with psychotic-like experiences. These findings could be applied in the formulation of early intervention strategies aimed at mitigating the risk of suicide. Future studies need to explore the effects of interventions targeting resilience for individuals with psychotic-like experiences.

Moderating and mediating effects of resilience between childhood trauma and psychotic-like experiences among college students.

BACKGROUND: Extensive literature revealed that childhood trauma serves as a significant risk factor for developing psychotic-like experiences (PLEs) among the general population. Resilience has been regarded as a protective factor against PLEs. However, it remains unclear what role resilience plays in the relationship between childhood trauma and PLEs. METHODS: A total of 4302 college students completed the web-based survey in January 2021. Participants completed self-report measures of sample characteristics variables, childhood trauma, and PLEs. Moderation and mediation analyses were adopted to examine the associations linking childhood trauma, resilience, and PLEs. RESULTS: PLEs were positively associated with childhood trauma while negatively associated with resilience. Resilience played a partially mediating role in the relationship between childhood trauma and PLEs. Additionally, resilience moderated the association of childhood trauma with PLEs. CONCLUSIONS: These findings indicated that resilience plays a crucial role in mediating the relationship between childhood trauma and PLEs, suggesting the potential clinical implication of enhancing resilience for the prevention and intervention of PLEs among college students.

The impact of spectral basis set composition on estimated levels of cingulate glutamate and its associations with different personality traits.

BACKGROUND: 1H-MRS is increasingly used in basic and clinical research to explain brain function and alterations respectively. In psychosis research it is now one of the main tools to investigate imbalances in the glutamatergic system. Interestingly, however, the findings are extremely variable even within patients of similar disease states. One reason may be the variability in analysis strategies, despite suggestions for standardization. Therefore, our study aimed to investigate the extent to which the basis set configuration- which metabolites are included in the basis set used for analysis- would affect the spectral fit and estimated glutamate (Glu) concentrations in the anterior cingulate cortex (ACC), and whether any changes in levels of glutamate would be associated with psychotic-like experiences and autistic traits. METHODS: To ensure comparability, we utilized five different exemplar basis sets, used in research, and two different analysis tools, r-based spant applying the ABfit method and Osprey using the LCModel. RESULTS: Our findings revealed that the types of metabolites included in the basis set significantly affected the glutamate concentration. We observed that three basis sets led to more consistent results across different concentration types (i.e., absolute Glu in mol/kg, Glx (glutamate + glutamine), Glu/tCr), spectral fit and quality measurements. Interestingly, all three basis sets included phosphocreatine. Importantly, our findings also revealed that glutamate levels were differently associated with both schizotypal and autistic traits depending on basis set configuration and analysis tool, with the same three basis sets showing more consistent results. CONCLUSIONS: Our study highlights that scientific results may be significantly altered depending on the choices of metabolites included in the basis set, and with that emphasizes the importance of carefully selecting the configuration of the basis set to ensure accurate and consistent results, when using MR spectroscopy. Overall, our study points out the need for standardized analysis pipelines and reporting.

Pixels and perception: Mapping the association between digital media and psychotic-like experiences in adolescents.

INTRODUCTION: Psychotic-like experiences (PLEs) during adolescence can lead to psychotic disorders. Digital media usage has been suggested to link to PLEs, but research is limited on how different types of screen exposure may differentially relate to PLEs over time. This study aimed to examine longitudinal associations between screen usage patterns and PLEs in adolescents. METHODS: Participants comprised 11,876 adolescents assessed annually from ages 9-12 years as part of the Adolescent Brain Cognitive Development study (ABCD). Screen usage (TV, video games, online video, social media, texting, video chat) and PLEs were assessed via self-report. Longitudinal network analysis models were estimated to examine connections between screen usage types and PLEs across three time points. RESULTS: Two clusters were formed, including digital media for socializing (e.g., social media/texting/video chat) and digital media for entertainment (e.g., online video/video games/TV). Texting and online video(s) had the highest centrality at each time point, suggesting importance in the network. PLE symptoms of hallucinations and concentration difficulties exhibited higher centrality than other symptoms. Online video and TV were influential bridges between screen usage and PLEs. Network structure significantly differed between ages 9-10 and 10-12 years, but global strength was unchanged over time. DISCUSSION: Results highlight the importance of understanding the associations between specific screen usage types and PLE symptoms. Texting and online video usage appear most influential in the development of adolescent PLEs over time. Findings can inform targeted interventions to promote healthy screen habits and reduce PLEs in at-risk youth.

Associations between digital media use and psychotic experiences in young adults of Quebec, Canada: a longitudinal study.

PURPOSE: Digital media use has been associated with psychotic experiences in youth from the community, but the direction of association remains unclear. We aimed to examine between- and within-person associations of digital media use and psychotic experiences in youth. METHODS: The sample included 425 participants aged 18-25 years (82.5% female) from the community, followed between May 2021 and January 2022 over 3 time points-of which 263 participants (61.9%) completed at least 2. Digital media use was self-reported as time spent daily on TV and streaming platforms, social media, and video games over the past 3 months. Psychotic experiences in the past 3 months were measured with the 15-item Community Assessment of Psychic Experiences. Associations between digital media use and psychotic experiences were estimated using a random-intercept cross-lagged panel model. RESULTS: On average, individuals who reported greater digital media use also reported higher levels of psychotic experiences (r = 0.34, 95% CI 0.15, 0.53). However, a person's variation in digital media use, relative to their personal average, was not significantly associated with subsequent variations in their levels of psychotic experiences, or vice-versa. Results were similar across TV/streaming, social media and video game use, and after adjusting for age, sex, education, sleep, physical activity, and cannabis use. CONCLUSION: Individuals with a tendency for higher levels of digital media use also had a tendency for higher levels of psychotic experiences. Understanding this association may help personalize mental health interventions for people with psychotic experiences, which may be offered digitally to promote their accessibility.

Lifetime prevalence of psychotic-like experiences and associated factors in Chile.

INTRODUCTION: Psychotic-like experiences (PLEs), which include hallucinations and delusional experiences, are usually present in healthy populations, and their persistence, quality, and severity are associated with the development of psychiatric diseases, including schizophrenia and other poor psychosocial outcomes. Urbanicity, depression, and other psychosocial stressors have been associated with PLEs. However, evidence of PLEs in Latin American (LATAM) countries is still scarce, and there are no studies about PLEs in Chile. The main aim of this study is to describe the prevalence of PLEs in a nationally representative sample according to other social determinants of health. METHODS: The last results of the Chilean National Health Survey (ENS 2016-2017) were analyzed. PLEs were obtained from the Composite International Diagnostic Interview (CIDI) 3.0 and included in this survey. Other psychosocial variables (age, sex, educational level, financial stress, depressive symptoms, and urbanicity) were also included for further analysis. Exclusion criteria were (1) > = 65 and < 18 years old, and (2) previous diagnosis or treatment for schizophrenia or bipolar disorder. Descriptive statistics were used to describe data, and Poisson regression models were performed to weight variables and find psychosocial correlations with PLEs. RESULTS: 2095 subjects were considered for this study (women 62.9% and mean age = 42.5, SD = 13.5). The lifetime prevalence of the PLEs (> = 1 PLE) in Chile was 12.9%. Visual hallucinations were the most common PLE (9.6%), and ideas of reference were the least common (0.4%). The Poisson regression model showed a higher prevalence of PLEs in the Gran Concepción conurbation (OR = 2.56) and Gran Valparaíso conurbation (OR = 1.69) compared with non-big cities. On the other hand, the 18-24 year group had higher PLEs prevalence compared to other age groups. No correlations were found with educational status, financial stress, or depressive symptoms. CONCLUSIONS: A relatively high prevalence of PLEs was found in the Chilean general population, particularly in youth living in large urban areas (Gran Valparaíso and Gran Concepción), which is compatible with previous research. Considering that there were no correlations between low educational level and financial or depressive symptoms, it is necessary to have more studies that correlate other urban relevant variables, such as natural disasters, drug consumption, and domestic or neighborhood violence.

Loneliness and psychotic-like experiences in middle-aged and older adults: the mediating role of selective attention to threat and external attribution biases.

OBJECTIVES: Loneliness has been associated with psychotic-like experiences (PLEs) in the general population, but the mechanisms underlying this association are poorly understood. Theoretical models, corroborated by empirical findings, signify the key role of biased cognition in both loneliness and psychosis. This study tested whether two cognitive biases - Selective Attention to Threat (ATB) and External Attribution Bias (EAB) - account for the association between loneliness and PLEs. METHOD: A convenience sample (n = 357) of middle-aged and older adults (aged 40+) was recruited online from the UK population. The parallel mediation model with two the aforementioned cognitive biases as mediators was tested. RESULTS: A mediation effect between loneliness and PLEs via ATB (ab1 = 0.441, 95% CI = [0.264, 0.646]) and EAB (ab2 = 0.354, 95% CI [0.124, 0.627] was established. This model remained significant after controlling for the current symptoms of anxiety and depression. CONCLUSION: Greater loneliness was associated with a higher rate of PLEs in the sample of middle-aged and older adults. This association was fully explained by ATB and EAB, independent of the current symptoms of anxiety and depression.

Social isolation and poor mental health in young people: testing genetic and environmental influences in a longitudinal cohort study.

We assessed genetic and environmental influences on social isolation across childhood and the overlap between social isolation and mental health symptoms including depression symptoms, conduct problems, and psychotic-like experiences from adolescence to young adulthood. Participants included 2,232 children from the Environmental Risk Longitudinal Twin Study. Social isolation was measured at ages 5, 7, 10, 12, and 18. A Cholesky decomposition was specified to estimate the genetic and environmental influences on social isolation across ages 5, 7, 10, and 12. An independent pathway model was used to assess additive genetic (A), shared environmental (C), and non-shared environmental (E) influences on the overlap between social isolation and mental health problems from age 12 to 18. Genetic and non-shared environmental influences accounted for half of the variance in childhood social isolation. Genetic influences contributed to the continuity of social isolation across childhood, while non-shared environmental influences were age-specific. The longitudinal overlap between social isolation and mental health symptoms was largely explained by genetic influences for depression symptoms (r = 0.15-0.24: 82-84% A, 11-12% C, and 5-6% E) and psychotic-like experiences (r = 0.13-0.15: 81-91% A, 0-8% C, and 9-11% E) but not conduct problems (r = 0.13-0.16; 0-42% A, 42-81% C, 16-24% E). Our findings emphasise that rather than a risk factor or an outcome, social isolation is aetiologically intertwined with the experience of poor mental health. An integrative assessment of social isolation could be a helpful indicator of underlying mental health symptoms in young people.

Bidirectional associations between short sleep duration, insomnia symptoms, and psychotic-like experiences in adolescents.

This study investigates the prospective associations between short sleep duration, insomnia symptoms, and psychotic-like experiences (PLEs) in a large sample of Chinese adolescents. This study utilized a three-timepoint repeated cross-sectional survey with two nested longitudinal subsamples. A total of 17,722 adolescents were assessed at baseline (April 21 to May 12, 2021) and six months later (December 17 to 26, 2021). Out of these, 15,694 adolescents provided complete responses to the questions at baseline and one year later (May 17 - June 6, 2022). A self-administered questionnaire was used to measure sample characteristics (at baseline), sleep duration, insomnia symptoms, and PLEs (at each assessment), and negative life events (at two follow-ups). Baseline short sleep duration and insomnia symptoms predicted frequent PLEs at both follow-up assessments. Additionally, baseline frequent PLEs also predicted insomnia symptoms at six months and one year later. However, when controlling for confounders, PLEs at baseline only predicted short sleep duration at six months, and not at one year. This study reveals bidirectional prospective relationships between short sleep duration, insomnia symptoms, and PLEs, even after controlling for covariates. Therefore, it is crucial to assess both sleep patterns and PLEs in order to promote optimal sleep and mental health among adolescents.

Prevalence of psychotic-like experiences and their association with depression symptoms among patients entering adolescent psychiatric care.

BACKGROUND: Psychotic-like experiences (PLEs) are common in clinical adolescent samples and form a continuum based on their frequency and intensity. PLEs can have harmful effects on both behaviour and affect. METHODS: Prevalence and subjective distress due to PLEs were assessed with the Prodromal Questionnaire-Brief (PQ-B) and depressive symptoms with the Beck Depression Inventory (BDI-21A) among adolescents (N = 399; 71.7% female, mean age 14.9 years, range 13-18) entering specialized adolescent psychiatric services. Various PQ-B Distress scale cut-off points were tested for their ability to detect high and low BDI scores using the superiority index, the effect size for mean difference, and spline regressions. RESULTS: The mean number of endorsed PLEs assessed with the PQ-B was 3.27 (SD 3.64; males: M 1.75; SD 2.78; females: M 3.89; SD 3.78), while mean PQ-B Distress scores were 20.33 (SD 18.03; males: M 11.84; SD 13.90; females: M 23.74; SD 18.40). The most common PLE within both genders were experiences of paranoia and suspiciousness, with a prevalence of 59.9%. BDI scores and PQ-B distress scores were strongly associated (r = 0.534, p<.001). Superiority indices, effect sizes, and spline regressions indicated that a low PQ-B Distress cut-off of 2 or 3 was most informative both when using BDI as a continuous variable and when dichotomized as mild depression (≥10) or major depressive disorder (≥16). CONCLUSION: PLEs are common among adolescent entering psychiatric care. Even a relatively small amount of distress due to PLEs indicates clinical levels of depressive symptoms.

Midwives' perspectives and perceptions in relation to perinatal psychotic-like experiences: a qualitative study.

BACKGROUND: Psychotic-like experiences (PLEs) refer to subclinical experiences consistent with psychosis that may include hearing, feeling or seeing things that others cannot, or experiencing unusual beliefs. These experiences appear to be more common during the perinatal period. There appear to be barriers which make it difficult for midwives to support mothers with mental health difficulties. However, it is important that midwives can provide support with PLEs. AIM: This study aimed to explore UK midwives' perspectives and perceptions relating to mothers' psychotic-like experiences in the perinatal period. METHODS: A qualitative study using semi-structured interviews with ten midwives recruited online was conducted. Transcripts were analysed using thematic analysis. RESULTS: Four themes were developed: (1) Identifying psychotic-like experiences would be complicated; (2) Psychotic-like experiences can feel overwhelming for women and midwives; (3) This is my responsibility: I'll do what I can to support women even if it's hard; and (4) The system feels unsafe and insecure which makes the anticipated role in supporting psychotic-like experiences harder. CONCLUSION: Midwives described their motivation to support mothers with PLEs but articulated many factors that made this difficult. The results emphasise the importance of training and guidance for midwives to support them being able to offer support and information to mothers. The findings also highlight the importance of systemic safety for midwives alongside support through supervision and reflective practice.

Strengthening associations between psychotic like experiences and suicidal ideation and behavior across middle childhood and early adolescence.

BACKGROUND: Understanding risk factors related to suicidal ideation (SI) and suicidal behaviors (SB) in youth is important for informing prevention and intervention efforts. While it appears that psychotic-like experiences (PLEs) are strongly associated with both SI and SB at different points across the lifespan, the longitudinal nature of this relationship in middle childhood and early adolescence is understudied. METHODS: The study used the unique longitudinal Adolescent Brain Cognitive Development Study data. Mixed effects linear models examined associations between PLEs and SI and SB over time using three time points of data from ages 9-13. RESULTS: First, analyses indicated that endorsement of SI and SB increased as youth grew older for those with increased distressing PLEs. Analyses found evidence of bidirectional relationships between PLEs with SI and SB, with evidence that PLEs at baseline were associated with worsening SI and SB over time, including a transition from SI to SB (ß = 0.032, FDRp = 0.002). Exploratory analyses showed consistent evidence for strengthened associations over time for higher delusional ideation with both SI and SB (ßs > 0.04, FDRps < 0.001), and for perceptual distortions with SB (ßs = 0.046, FDRp < 0.001). When accounting for general psychopathology, for SB, the strengthened associations over time was significantly stronger for PLEs (ß = 0.053, FDRp < 0.001) compared to general psychopathology (ß = 0.022, FDRp = 0.01). CONCLUSIONS: The present study indicates both SI and SB show strengthened associations with PLEs over time, and that baseline PLEs may predict worsening of suicidality over time. The findings are important clarifications about the nature of the associations between youth-reported PLEs and suicidality over time.

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

BACKGROUND: Psychotic-like experiences (PLEs) are risk factors for the development of psychiatric conditions like schizophrenia, particularly if associated with distress. As PLEs have been related to alterations in both white matter and cognition, we investigated whether cognition (g-factor and processing speed) mediates the relationship between white matter and PLEs. METHODS: We investigated two independent samples (6170 and 19 891) from the UK Biobank, through path analysis. For both samples, measures of whole-brain fractional anisotropy (gFA) and mean diffusivity (gMD), as indications of white matter microstructure, were derived from probabilistic tractography. For the smaller sample, variables whole-brain white matter network efficiency and microstructure were also derived from structural connectome data. RESULTS: The mediation of cognition on the relationships between white matter properties and PLEs was non-significant. However, lower gFA was associated with having PLEs in combination with distress in the full available sample (standardized ß = -0.053, p = 0.011). Additionally, lower gFA/higher gMD was associated with lower g-factor (standardized ß = 0.049, p < 0.001; standardized ß = -0.027, p = 0.003), and partially mediated by processing speed with a proportion mediated of 7% (p = < 0.001) for gFA and 11% (p < 0.001) for gMD. CONCLUSIONS: We show that lower global white matter microstructure is associated with having PLEs in combination with distress, which suggests a direction of future research that could help clarify how and why individuals progress from subclinical to clinical psychotic symptoms. Furthermore, we replicated that processing speed mediates the relationship between white matter microstructure and g-factor.

Childhood adversity and recurrence of psychotic experiences during adolescence: the role of mediation in an analysis of a population-based longitudinal cohort study.

BACKGROUND: Psychotic experiences (PEs) are relatively common in childhood and adolescence and are associated with increased risk of functional issues and psychiatric illness in young adulthood, and PEs that recur are associated with increased risk of poorer psychiatric and functional outcomes. Childhood adversity is a well-established risk factor for PEs. The aim of this study was to investigate (1) the relationship between childhood adversity and recurring PEs in adolescence and (2) candidate mediators of that relationship. METHODS: We used data from Cohort '98 of the Growing Up in Ireland study (n = 6039) at three time points (ages 9, 13 and 17) to investigate the relationship between childhood adversity (parent-reported at age 9), recurring PEs (measured using a subset of the Adolescent Psychotic-like Symptoms Screener at ages 13 and 17). The mediating roles of parent-child relationship, internalising and externalising difficulties, self-concept, physical activity, dietary quality, perceived neighbourhood safety and friendship quantity were investigated using the KHB path decomposition method. RESULTS: Childhood adversity was associated with an increased risk of recurring PEs with a population attributable fraction of 23%. Internalising difficulties and self-concept explained 13% of the relationship between childhood adversity and PEs suggesting a partial mediation. A significant direct effect remained between childhood adversity and recurring PEs. CONCLUSIONS: The established relationship between childhood adversity and PEs may be mainly driven by the relationship between childhood adversity and recurring PEs. Internalising difficulties and self-concept together mediate part of the relationship between childhood adversity and recurring PEs.

Clinical significance of psychotic-like experiences across U.S. ethnoracial groups.

BACKGROUND: Prevalence of psychotic-like experiences (PLEs) - reports of hallucinations and delusional thinking not meeting criteria for psychotic disorder - varies substantially across ethnoracial groups. What explains this range of PLE prevalence? Despite extensive research, the clinical significance of PLEs remains unclear. Are PLE prevalence and clinical severity differentially associated across ethnoracial groups? METHODS: We examined the lifetime prevalence and clinical significance of PLEs across ethnoracial groups in the Collaborative Psychiatric Epidemiology Surveys (N = 11 139) using the Composite International Diagnostic Interview (CIDI) psychosis symptom screener. Outcomes included mental healthcare use (inpatient, outpatient), mental health morbidity (self-perceived poor/fair mental health, suicidal ideation or attempts), and impairment (role interference). Individuals with outcome onsets prior to PLE onset were excluded. We also examined associations of PLEs with CIDI diagnoses. Cox proportional-hazards regression and logistic regression modeling identified associations of interest. RESULTS: Contrary to previous reports, only Asian Americans differed significantly from other U.S. ethnoracial groups, reporting lower lifetime prevalence (6.7% v. 8.0-11.9%) and mean number (0.09 v. 0.11-0.18) of PLEs. In multivariate analyses, PLE clinical significance showed limited ethnoracial variation among Asian Americans, non-Caribbean Latinos, and Afro-Caribbeans. In other groups, mental health outcomes showed significant ethnoracial clustering by outcome (e.g. hospitalization and role interference with Caribbean-Latino origin), possibly due to underlying differences in psychiatric disorder chronicity or treatment barriers. CONCLUSIONS: While there is limited ethnoracial variation in U.S. PLE prevalence, PLE clinical significance varies across U.S. ethnoracial groups. Clinicians should consider this variation when assessing PLEs to avoid exaggerating their clinical significance, contributing to mental healthcare disparities.

Schizophrenia polygenic risk score in psychosis proneness.

Schizophrenia (SZ) is a complex disorder with a highly polygenic inheritance. It can be conceived as the extreme expression of a continuum of traits that are present in the general population often broadly referred to as schizotypy. However, it is still poorly understood how these traits overlap genetically with the disorder. We investigated whether polygenic risk for SZ is associated with these disorder-related phenotypes (schizotypy, psychotic-like experiences, and subclinical psychopathology) in a sample of 253 non-clinically identified participants. Polygenic risk scores (PRSs) were constructed based on the latest SZ genome-wide association study using the PRS-CS method. Their association with self-report and interview measures of SZ-related traits was tested. No association with either schizotypy or psychotic-like experiences was found. However, we identified a significant association with the Motor Change subscale of the Comprehensive Assessment of At-Risk Mental States (CAARMS) interview. Our results indicate that the genetic overlap of SZ with schizotypy and psychotic-like experiences is less robust than previously hypothesized. The relationship between high PRS for SZ and motor abnormalities could reflect neurodevelopmental processes associated with psychosis proneness and SZ.