Association between stressful life events and psychotic experiences in adolescence: evidence for gene-environment correlations

Immersive virtual reality as a novel approach to investigate the association between adverse events and adolescent paranoid ideation

PURPOSE

Paranoid ideation is common among adolescents, yet little is known about the precursors. Using a novel immersive virtual reality (VR) paradigm, we tested whether experiences of bullying, and other interpersonal/threatening events, are associated with paranoid ideation to a greater degree than other types of (i) non-interpersonal events or (ii) adverse childhood experiences.

METHODS

Self-reported exposure to adverse life events and bullying was collected on 481 adolescents, aged 11-15. We used mixed effects (multilevel) linear regression to estimate the magnitude of associations between risk factors and paranoid ideation, assessed by means of adolescents' reactions to ambiguously behaving avatars in a VR school canteen, adjusting for putative confounders (gender, year group, ethnicity, free school meal status, place of birth, family mental health problems).

RESULTS

Lifetime exposure to interpersonal/threatening events, but not non-interpersonal events or adverse circumstances, was associated with higher levels of state paranoid ideation, with further evidence that the effect was cumulative (1 type: ϐadj 0.07, 95% CI -0.01-0.14; 2 types: ϐadj 0.14, 95% CI 0.05-0.24; 3 + types: ϐadj 0.24, 95% CI 0.12-0.36). More tentatively, for girls, but not boys, recent bullying was associated with heightened paranoid ideation with effect estimates ranging from ϐadj 0.06 (95% CI -0.02-0.15) for physical bullying to ϐadj 0.21 (95% CI 0.10-0.32) for cyber bullying.

CONCLUSIONS

Our data suggest a degree of specificity for adversities involving interpersonal threat or hostility, i.e. those that involve unwanted interference and/or attempted control of an individual's personal boundaries being associated with heightened levels of state paranoid ideation among adolescents.

Effects of Goal Management Training on self-efficacy, self-esteem, and quality of life for persons with schizophrenia spectrum disorders

Persons with schizophrenia often show executive dysfunction assessed with both subjective (self-report) and objective (neuropsychological tests) measures. In a recent randomized controlled trial (RCT), subjective executive functioning in everyday life was improved following Goal Management Training (GMT). The aim of the current study is to investigate the potential of GMT to improve secondary well-being outcomes from that RCT, including self-esteem, self-efficacy, and quality of life in persons with schizophrenia spectrum disorders. Since well-being is frequently lower in persons with schizophrenia compared to healthy individuals, further knowledge about well-being as an outcome after cognitive remediation may have implications for clinical treatment. Sixty-five participants were randomly assigned to GMT (n = 31) or a waiting list control condition (n = 34). Assessments were conducted at baseline (T1), immediately after the intervention (T2-5 weeks), and at six-month follow-up (T3). Measures included the Rosenberg Self-Esteem Scale, the Perceived Quality of Life Scale, and the General Self-Efficacy Scale. Results were analyzed using a linear mixed model analysis for repeated measures. There were no significant effects of GMT on self-esteem or quality of life. Only the GMT group showed a significant increase in self-efficacy that was most evident at six months follow-up, F(1, 34) = 10.71, p = 0.002, d = 0.71. Improved self-efficacy was found to correlate significantly with a reduction in perceived executive dysfunction in an exploratory post hoc analysis. Our findings demonstrate the potential of GMT in improving self-efficacy in schizophrenia Clinical trial registration:https://clinicaltrials.gov, NCT03048695.

The interaction between polygenic risk and environmental influences: A direct test of the 3P model of insomnia in adolescents

BACKGROUND

Stress is a universal phenomenon and one of the most common precipitants of insomnia. However, not everyone develops insomnia after experiencing a stressful life event. This study aims to test aspects of Spielman's '3P model of insomnia' (during adolescence) by exploring the extent to which: (a) insomnia symptoms are predicted by polygenic scores (PGS); (b) life events predict insomnia symptoms; (c) the interaction between PGS and life events contribute to the prediction of insomnia symptoms; (d) gene-environment interaction effects remain after controlling for sex.

METHODS

The sample comprised 4,629 twins aged 16 from the Twin Early Development Study who reported on their insomnia symptoms and life events. PGS for insomnia were calculated. In order to test the main hypothesis of this study (a significant interaction between PGS and negative life events), we fitted a series of mixed effect regressions.

RESULTS

The best fit was provided by the model including sex, PGS for insomnia, negative life events, and their interactions (AIC = 26,158.7). Our results show that the association between insomnia symptoms and negative life events is stronger for those with a higher genetic risk for insomnia.

CONCLUSIONS

This work sheds light on the complex relationship between genetic and environmental factors implicated for insomnia. This study has tested for the first time the interaction between genetic predisposition (PGS) for insomnia and environmental stressors (negative life events) in adolescents. This work represents a direct test of components of Spielman's 3P model for insomnia which is supported by our results.

Effects of independent versus dependent stressful life events on major symptom domains of schizophrenia

We evaluated two models to link stressful life events (SLEs) with the psychopathology of schizophrenia spectrum disorders (SSD). We separated SLEs into independent (iSLEs, unlikely influenced by one's behavior) and dependent (dSLEs, likely influenced by one's behavior). Stress-diathesis and stress generation models were evaluated for the relationship between total, i- and d- SLEs and the severity of positive, negative, and depressive symptoms in participants with SSD. Participants with SSD (n = 286; 196 males; age = 37.5 ± 13.5 years) and community controls (n = 121; 83 males; 35.4 ± 13.9 years) completed self-report of lifetime negative total, i- and d- SLEs. Participants with SSD reported a significantly higher number of total SLEs compared to controls (B = 1.11, p = 6.4 × 10-6). Positive symptom severity was positively associated with the total number of SLEs (β = 0.20, p = 0.001). iSLEs (β = 0.11, p = 0.09) and dSLEs (β = 0.21, p = 0.0006) showed similar association with positive symptoms (p = 0.16) suggesting stress-diathesis effects. Negative symptom severity was negatively associated with the number of SLEs (β = -0.19, p = 0.003) and dSLEs (β = -0.20, p = 0.001) but not iSLEs (β = -0.04, p = 0.52), suggesting stress generation effects. Depressive symptom severity was positively associated with SLEs (β = 0.34, p = 1.0 × 10-8), and the association was not statistically stronger for dSLEs (β = 0.33, p = 2.7 × 10-8) than iSLEs (β = 0.21, p = 0.0006), p = 0.085, suggesting stress-diathesis effects. The SLE - symptom relationships in SSD may be attributed to stress generation or stress-diathesis, depending on symptom domain. Findings call for a domain-specific approach to clinical intervention for SLEs in SSD.

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.

Effect of stressful life events on subclinical psychotic symptoms in first-degree relatives and healthy controls

Exposure to Stressful Life Events (SLEs) has been linked to psychosis. However, the combined effect of SLEs and familial risk on subclinical psychotic symptoms over time remains unknown. The objective of the present study was to investigate the effect of SLEs on the level of subclinical psychotic symptoms in individuals with and without familial vulnerability for psychosis. Data were collected from siblings of individuals diagnosed with psychotic disorder and healthy controls at baseline (N = 293) and three years later at follow-up (N = 928). We assessed self-reported and observer-rated subclinical positive, negative, and depressive psychotic symptoms. Participants reported the number of SLEs in the preceding 6 months. A multilevel multivariate regression analysis revealed a positive association between the retrospectively assessed number of SLEs and symptom levels, regardless of vulnerability status (p < .001 for all outcomes). The prospective analysis demonstrated that exposure to SLEs at baseline predicted higher levels of subclinical psychotic symptoms at follow-up. However, after controlling for the level of symptoms at baseline, these associations were no longer significant. Again, the vulnerability status did not modify these results. Nevertheless, siblings in our sample were approximating the end of the critical period for the development of psychotic disorder (mean age at baseline M = 29 and follow-up M = 34). The findings partly support the vulnerability-stress model of psychosis, yet do not confirm the role of familial risk in this association. SLEs may represent a risk factor for psychosis at a population level, thus supporting the continuity of the psychosis spectrum in terms of associated risk factors.

Heritability of Psychotic Experiences in Adolescents and Interaction With Environmental Risk

IMPORTANCE

Genetic risk factors are known to play a role in the etiology of psychotic experiences in the general population. Little is known about whether these risk factors interact with environmental risks for psychotic experiences.

OBJECTIVE

To assess etiological heterogeneity and exposure to environmental risks associated with psychotic experiences in adolescence using the twin design.

DESIGN, SETTING, AND PARTICIPANTS

This twin study, conducted from December 1, 2014, to August 31, 2020, included a UK-based sample of twin pairs aged 16 years. This investigation evaluated the extent to which the genetic variance underlying psychotic experiences and the magnitude of the heritability of psychotic experiences was moderated by exposure to 5 environmental risk factors (bullying, dependent life events, cannabis use, tobacco use, and low birth weight). Psychotic experiences were assessed by 5 self-reported measures and 1 parent-reported measure. Participants' exposure to environmental risks was assessed at birth and age 12 to 16 years. Structural equation models were used to assess differences in the variance in and heritability of psychotic experiences across these exposures, while controlling for gene-environment correlation effects. Analyses were repeated in an independent Swedish sample. Data analyses were performed from September 1, 2018, to August 31, 2020.

MAIN OUTCOMES AND MEASURES

Primary outcome measures were exposure to environmental factors, as measured by a composite score, and psychotic experiences.

RESULTS

A total of 4855 twin pairs (1926 female same-sex pairs, 1397 male same-sex pairs, and 1532 opposite-sex pairs) were included from the Twins Early Development Study (TEDS), and 6435 twin pairs (2358 female same-sex pairs, 1861 male same-sex pairs, and 2216 opposite-sex pairs) were included from the Child and Adolescent Twin Study in Sweden (CATSS). Mean age of twins from TEDS was 16.5 years. Mean age of twins from CATSS was 18.6 years. More exposure to environmental risk factors was associated with having more psychotic experiences. The relative contribution of genetic influences to psychotic experiences was lower with increasing environmental exposure for paranoia (44%; 95% CI, 33%-53% to 38%; 95% CI, 14%-58%), cognitive disorganization (47%; 95% CI, 38%-51% to 32%; 95% CI, 11%-45%), grandiosity (41%; 95% CI, 29%-52% to 32%; 95% CI, 9%-48%), and anhedonia (49%; 95% CI, 42%-53% to 37%; 95% CI, 15%-54%). This pattern was replicated for the measure of psychotic experiences in the independent Swedish replication sample. The heritability of hallucinations and parent-rated negative symptoms remained relatively constant.

CONCLUSIONS AND RELEVANCE

Findings of this twin study suggest that environmental factors play a greater role in the etiology of psychotic experiences than genetic factors. The relative importance of environmental factors is even higher among individuals exposed to environmental risks for psychotic experiences, highlighting the importance of a diathesis-stress or bioecological framework for understanding adolescent psychotic experiences.

A randomized controlled trial of Goal Management Training for executive functioning in schizophrenia spectrum disorders or psychosis risk syndromes

BACKGROUND

Executive functioning is essential to daily life and severely impaired in schizophrenia and psychosis risk syndromes. Goal Management Training (GMT) is a theoretically founded, empirically supported, metacognitive strategy training program designed to improve executive functioning.

METHODS

A randomized controlled parallel group trial compared GMT with treatment as usual among 81 participants (GMT, n = 39 versus Wait List Controls, n = 42) recruited from an early intervention for psychosis setting. Computer generated random allocation was performed by someone independent from the study team and raters post-intervention were unaware of allocation. The primary objective was to assess the impact of GMT administered in small groups for 5 weeks on executive functioning. The secondary objective was to explore the potential of the intervention in influencing daily life functioning and clinical symptoms.

RESULTS

GMT improved self-reported executive functioning, measured with the Behavior Rating Inventory of Executive Function - Adult version (BRIEF-A), significantly more than treatment as usual. A linear mixed model for repeated measures, including all partial data according to the principle of intention to treat, showed a significant group x time interaction effect assessed immediately after intervention (post-test) and 6 months after intervention (follow-up), F = 8.40, p .005, r .37. Improvement occurred in both groups in objective executive functioning as measured by neuropsychological tests, functional capacity, daily life functioning and symptoms of psychosis rated by clinicians. Self-reported clinical symptoms measured with the Symptoms Check List (SCL-10) improved significantly more after GMT than after treatment as usual, F = 5.78, p .019, r .29. Two participants withdrew due to strenuous testing and one due to adverse effects.

CONCLUSIONS

GMT had clinically reliable and lasting effects on subjective executive function. The intervention is a valuable addition to available treatment with considerable gains at low cost.

TRIAL REGISTRATION

Registered at clinicaltrials.gov NCT03048695 09/02/2017.

Racism and psychosis: an umbrella review and qualitative analysis of the mental health consequences of racism

Black people and People of Color are disproportionately affected by racism and show increased rates of psychosis. To examine whether racialized migrant groups are particularly exposed to racism and therefore have higher risks for psychosis, this paper (1) systematically assesses rates of psychosis among racialized migrant groups concerning the country of origin, and (2) analyzes interviews regarding the association of racism experiences with psychosis-related symptoms in racialized Black people and People of Color populations in Germany. We present an umbrella review of meta-analyses that report the incidence of positive symptoms (e.g., hallucinations and delusions) and negative symptoms (e.g., apathy and incoherent speech) of diagnosed schizophrenia, other non-affective psychotic disorders (e.g., schizoaffective disorder) or first-episode psychosis among migrants by country of origin. We also report 20 interviews with first- and second-generation migrants racialized as Black and of Color in Germany to capture and classify their experiences of racism as well as racism-associated mental health challenges. In the umbrella review, psychosis risk was greatest when migration occurred from developing countries. Effect size estimates were even larger among Caribbean and African migrants. In the qualitative study, the application of the constant comparative method yielded four subordinate themes that form a subclinical psychosis symptomatology profile related to experiences of racism: (1) a sense of differentness, (2) negative self-awareness, (3) paranoid ideation regarding general persecution, and (4) self-questioning and self-esteem instability. We here provide converging evidence from a quantitative and qualitative analysis that the risk of poor mental health and psychotic experiences is related to racism associated with minority status and migration.

Dynamic interplay between life events and course of psychotic disorders: 10-year longitudinal study following first admission

BACKGROUND

Life events (LEs) are a risk factor for first onset and relapse of psychotic disorders. However, the impact of LEs on specific symptoms - namely reality distortion, disorganization, negative symptoms, depression, and mania - remains unclear. Moreover, the differential effects of negative v. positive LEs are poorly understood.

METHODS

The present study utilizes an epidemiologic cohort of patients (N = 428) ascertained at first-admission for psychosis and followed for a decade thereafter. Symptoms were assessed at 6-, 24-, 48-, and 120-month follow-ups.

RESULTS

We examined symptom change within-person and found that negative events in the previous 6 months predicted an increase in reality distortion (β = 0.07), disorganized (β = 0.07), manic (β = 0.08), and depressive symptoms (β = 0.06), and a decrease in negative symptoms (β = -0.08). Conversely, positive LEs predicted fewer reality distortion (β = -0.04), disorganized (β = -0.04), and negative (β = -0.13) symptoms, and were unrelated to mood symptoms. A between-person approach to the same hypotheses confirmed that negative LEs predicted change in all symptoms, while positive LEs predicted change only in negative symptoms. In contrast, symptoms rarely predicted future LEs.

CONCLUSIONS

These findings confirm that LEs have an effect on symptoms, and thus contribute to the burden of psychotic disorders. That LEs increase positive symptoms and decrease negative symptoms suggest at least two different mechanisms underlying the relationship between LEs and symptoms. Our findings underscore the need for increased symptom monitoring following negative LEs, as symptoms may worsen during that time.

Life Event Stress and Reduced Cortical Thickness in Youth at Clinical High Risk for Psychosis and Healthy Control Subjects

BACKGROUND

A decline in cortical thickness during early life appears to be a normal neuromaturational process. Accelerated cortical thinning has been linked with conversion to psychosis among individuals at clinical high risk for psychosis (CHR-P). Previous research indicates that exposure to life event stress (LES) is associated with exaggerated cortical thinning in both healthy and clinical populations, and LES is also linked with conversion to psychosis in CHR-P. To date, there are no reports on the relationship of LES with cortical thickness in CHR-P. This study examines this relationship and whether LES is linked with cortical thinning to a greater degree in individuals at CHR-P who convert to psychosis compared with individuals at CHR-P who do not convert and healthy control subjects.

METHODS

Controlling for age and gender (364 male, 262 female), this study examined associations between LES and baseline cortical thickness in 436 individuals at CHR-P (375 nonconverters and 61 converters) and 190 comparison subjects in the North American Prodrome Longitudinal Study.

RESULTS

Findings indicate that prebaseline cumulative LES is associated with reduced baseline cortical thickness in several regions among the CHR-P and control groups. Evidence suggests that LES is a risk factor for thinner cortex to the same extent across diagnostic groups, while CHR-P status is linked with thinner cortex in select regions after accounting for LES.

CONCLUSIONS

This research provides additional evidence to support the role of LES in cortical thinning in both healthy youth and those at CHR-P. Potential underlying mechanisms of the findings and implications for future research are discussed.

The Babytwins Study Sweden (BATSS): A Multi-Method Infant Twin Study of Genetic and Environmental Factors Influencing Infant Brain and Behavioral Development

Twin studies can help us understand the relative contributions of genes and environment to phenotypic trait variation, including attentional and brain activation measures. In terms of applying methodologies such as electroencephalography (EEG) and eye tracking, which are key methods in developmental neuroscience, infant twin studies are almost nonexistent. Here, we describe the Babytwins Study Sweden (BATSS), a multi-method longitudinal twin study of 177 MZ and 134 DZ twin pairs (i.e., 622 individual infants) covering the 5-36 month time period. The study includes EEG, eye tracking and genetics, together with more traditional measures based on in-person testing, direct observation and questionnaires. The results show that interest in participation in research among twin parents is high, despite the comprehensive protocol. DNA analysis from saliva samples was possible in virtually all participants, allowing for both zygosity confirmation and polygenic score analyses. Combining a longitudinal twin design with advanced technologies in developmental cognitive neuroscience and genomics, BATSS represents a new approach in infancy research, which we hope to have impact across multiple disciplines in the coming years.

The clinical characterization of the patient with primary psychosis aimed at personalization of management

The current management of patients with primary psychosis worldwide is often remarkably stereotyped. In almost all cases an antipsychotic medica-tion is prescribed, with second-generation antipsychotics usually preferred to first-generation ones. Cognitive behavioral therapy is rarely used in the vast majority of countries, although there is evidence to support its efficacy. Psychosocial interventions are often provided, especially in chronic cases, but those applied are frequently not validated by research. Evidence-based family interventions and supported employment programs are seldom implemented in ordinary practice. Although the notion that patients with primary psychosis are at increased risk for cardiovascular diseases and diabetes mellitus is widely shared, it is not frequent that appropriate measures be implemented to address this problem. The view that the management of the patient with primary psychosis should be personalized is endorsed by the vast majority of clinicians, but this personalization is lacking or inadequate in most clinical contexts. Although many mental health services would declare themselves "recovery-oriented", it is not common that a focus on empowerment, identity, meaning and resilience is ensured in ordinary practice. The present paper aims to address this situation. It describes systematically the salient domains that should be considered in the characterization of the individual patient with primary psychosis aimed at personalization of management. These include positive and negative symptom dimensions, other psychopathological components, onset and course, neurocognition and social cognition, neurodevelopmental indicators; social functioning, quality of life and unmet needs; clinical staging, antecedent and concomitant psychiatric conditions, physical comorbidities, family history, history of obstetric complications, early and recent environmental exposures, protective factors and resilience, and internalized stigma. For each domain, simple assessment instruments are identified that could be considered for use in clinical practice and included in standardized decision tools. A management of primary psychosis is encouraged which takes into account all the available treatment modalities whose efficacy is supported by research evidence, selects and modulates them in the individual patient on the basis of the clinical characterization, addresses the patient's needs in terms of employment, housing, self-care, social relationships and education, and offers a focus on identity, meaning and resilience.

General psychopathology links burden of recent life events and psychotic symptoms in a network approach

Recent life events have been implicated in the onset and progression of psychosis. However, psychological processes that account for the association are yet to be fully understood. Using a network approach, we aimed to identify pathways linking recent life events and symptoms observed in psychosis. Based on previous literature, we hypothesized that general symptoms would mediate between recent life events and psychotic symptoms. We analyzed baseline data of patients at clinical high risk for psychosis and with recent-onset psychosis (n = 547) from the Personalised Prognostic Tools for Early Psychosis Management (PRONIA) study. In a network analysis, we modeled links between the burden of recent life events and all individual symptoms of the Positive and Negative Syndrome Scale before and after controlling for childhood trauma. To investigate the longitudinal associations between burden of recent life events and symptoms, we analyzed multiwave panel data from seven timepoints up to month 18. Corroborating our hypothesis, burden of recent life events was connected to positive and negative symptoms through general psychopathology, specifically depression, guilt feelings, anxiety and tension, even after controlling for childhood trauma. Longitudinal modeling indicated that on average, burden of recent life events preceded general psychopathology in the individual. In line with the theory of an affective pathway to psychosis, recent life events may lead to psychotic symptoms via heightened emotional distress. Life events may be one driving force of unspecific, general psychopathology described as characteristic of early phases of the psychosis spectrum, offering promising avenues for interventions.

Terminology and assessment tools of psychosis: A systematic narrative review

AIM

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

METHODS

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

RESULTS

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

DISCUSSION

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

Frequency of stressful life events and associations with mental health and general subjective health in the general population

Aim

We aim to determine the frequency of stressful life events (SLEs) and investigate the association of single and aggregated SLEs with mental health and general subjective health, which has not been reported for an aging representative sample to date.

Subjects and methods

A total of 12,947 participants (35–74 years old) of the Gutenberg Health Study (GHS) in Germany were analyzed. SLEs were analyzed at the item and aggregated level with unweighted and weighted sum scores. Additionally, the survey included measures of mental health, general subjective health and demographics. Descriptive analyses were stratified by sex, age and socioeconomic status.

Results

Multivariate analyses of variance with SLE at the item level revealed large main effects for sex (ηp2 = 0.30) and age (ηp2 = 0.30); a moderate effect was found for socioeconomic status (ηp2 = 0.08). Interaction effects of sex with age and SES were also significant, but with negligible effect sizes. Regression analyses revealed similar results for unweighted and weighted SLE sum scores controlling for sociodemographic variables, supporting the detrimental relations among cumulated SLEs, depression (β = 0.18/0.19) and anxiety (β =0.17/0.17), but not general health. Mental health indicators showed the highest correlations with single SLEs such as change of sleep habits or personal finances. Severe SLEs according to proposed weight scores showed no or only weak associations with mental health.

Conclusion

Representative data support a more distinct impact of SLEs on mental health than on general health. Single SLEs show strong associations with mental health outcome (e.g., change of sleep habits). The low associations between severe single SLEs and mental health merit further attention.

Adverse family life events during pregnancy and ADHD symptoms in five-year-old offspring

BACKGROUND

Prenatal exposure to maternal adverse life events has been associated with offspring ADHD, but the role of familial confounding is unclear. We aimed to clarify if adverse life events during pregnancy are related to ADHD symptoms in offspring, taking shared familial factors into account.

METHOD

Data were collected on 34,751 children (including 6,427 siblings) participating in the population-based Norwegian Mother and Child Cohort Study. During pregnancy, mothers reported whether they had experienced specific life events. We assessed ADHD symptoms in five-year-old children with the Conners' Parent Rating Scale-Revised: short form. We modeled the associations between life events and mean ADHD scores with ordinary linear regression in the full cohort, and with fixed-effect linear regression in sibling comparisons to adjust for familial confounding.

RESULTS

Children exposed to adverse life events had higher ADHD scores at age 5, with the strongest effect observed for financial problems (mean differences 0.10 [95% CI: 0.09, 0.11] in adjusted model), and the weakest for having lost someone close (0.02 [95% CI 0.01, 0.04] in adjusted model). Comparing exposure-discordant siblings resulted in attenuated estimates that were no longer statistically significant (e.g. mean difference for financial problems -0.03 [95% CI -0.07, 0.02]). ADHD scores increased if the mother had experienced the event as painful or difficult, and with the number of events, whereas sibling-comparison analyses resulted in estimates attenuated toward the null.

CONCLUSIONS

These results suggest that the association between adverse life events during pregnancy and offspring ADHD symptoms is largely explained by familial factors.

A Twin Study on the Association Between Psychotic Experiences and Tobacco Use During Adolescence

OBJECTIVE

Psychotic experiences (PE) are dimensional phenomena in the general population that resemble psychotic symptoms, such as paranoia and hallucinations. This is the first twin study to explore the degree to which tobacco use and PE share genetic or environmental influences. Previous studies on the association between adolescent tobacco use and PE have not considered PE dimensionally, included negative symptoms, or accounted for confounding by sleep disturbance and stressful life events.

METHOD

An unselected adolescent twin sample (N = 3,787 pairs; mean age = 16.16 years) reported on PE (paranoia, hallucinations, cognitive disorganization, grandiosity, and anhedonia) and regularity of tobacco use. Parents rated the twins' negative symptoms. Regression analyses were conducted while adjusted for sociodemographic characteristics, prenatal maternal smoking, cannabis use, sleep disturbance, and stressful life events. Bivariate twin modeling was used to estimate the degree of genetic and common and unique environmental influences shared between tobacco use and PE.

RESULTS

Regular smokers were significantly more likely to experience paranoia, hallucinations, cognitive disorganization, and negative symptoms (β = 0.17-0.34), but not grandiosity or anhedonia, than nonsmokers, after adjustment for confounders. Paranoia, hallucinations, and cognitive disorganization correlated ≥0.15 with tobacco use (r = 0.15-0.21, all p < .001). Significant genetic correlations (r_A=0.37-0.45) were found. Genetic influences accounted for most of the association between tobacco use and paranoia (84%) and cognitive disorganization (81%). Familial influences accounted for 80% of the association between tobacco use and hallucinations.

CONCLUSION

Tobacco use and PE during adolescence were associated after adjustment for confounders. They appear to co-occur largely because of shared genetic influences.

Suspiciousness in young minds: Convergent evidence from non-clinical, clinical and community twin samples

BACKGROUND

We validated the Social Mistrust Scale (SMS) and utilized it to examine the structure, prevalence, and heritability of social mistrust in a large sample of Chinese children and adolescents.

METHODS

In Study 1, a large sample of healthy twins (N=2094) aged 8 to 14years (M=10.27years, SD=2) completed the SMS. Structural equation modeling (SEM) was conducted to assess the structure of the SMS and to estimate the heritability of social mistrust in a sub-sample of twins (n=756 pairs). In Study 2, 32 adolescents with childhood-onset schizophrenia were compared with 34 healthy controls on levels of suspiciousness and clinical symptoms to examine the associations between the SMS and the Positive and Negative Syndrome Scale (PANSS).

RESULTS

We found a three-factor structure for social mistrust (home, school, and general mistrust). Social mistrust was found to be moderately - heritable (19%-40%), with mistrust at home most strongly influenced by genetic factors. Compared with 11.76% of the healthy controls, 56.25% of the adolescents with early-onset schizophrenia exhibited very high levels of social mistrust on all three subscales of the SMS. The SMS exhibited good discriminant validity in distinguishing adolescents with childhood-onset schizophrenia from healthy controls and showed associations with a broad range of symptoms assessed by the PANSS.

CONCLUSIONS

Social mistrust assessed by the SMS may be heritable. The SMS demonstrates good discriminant validity with clinical diagnoses of schizophrenia. However, it seems to be correlated with multiple aspects of psychopathology in the schizophrenia group, rather than being specific to delusional ideation/paranoia.

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.

In the eye of the beholder: Perceptions of neighborhood adversity and psychotic experiences in adolescence

Adolescent psychotic experiences increase risk for schizophrenia and other severe psychopathology in adulthood. Converging evidence implicates urban and adverse neighborhood conditions in the etiology of adolescent psychotic experiences, but the role of young people's personal perceptions of disorder (i.e., physical and social signs of threat) in their neighborhood is unknown. This was examined using data from the Environmental Risk Longitudinal Twin Study, a nationally representative birth cohort of 2,232 British twins. Participants were interviewed at age 18 about psychotic phenomena and perceptions of disorder in the neighborhood. Multilevel, longitudinal, and genetically sensitive analyses investigated the association between perceptions of neighborhood disorder and adolescent psychotic experiences. Adolescents who perceived higher levels of neighborhood disorder were significantly more likely to have psychotic experiences, even after accounting for objectively/independently measured levels of crime and disorder, neighborhood- and family-level socioeconomic status, family psychiatric history, adolescent substance and mood problems, and childhood psychotic symptoms: odds ratio = 1.62, 95% confidence interval [1.27, 2.05], p < .001. The phenotypic overlap between adolescent psychotic experiences and perceptions of neighborhood disorder was explained by overlapping common environmental influences, rC = .88, 95% confidence interval [0.26, 1.00]. Findings suggest that early psychological interventions to prevent adolescent psychotic experiences should explore the role of young people's (potentially modifiable) perceptions of threatening neighborhood conditions.

Steinberg and Durell (1968) revisited: increased rates of First Episode Psychosis following military induction in Greek Army Recruits

Since the seminal study of Steinbeck and Durell (1968), few epidemiological studies have attempted to replicate whether psychosocial stress precipitates the onset of a first psychotic episode. Our aim was to support or refute the finding of elevated psychosis incidence in the first month of army induction and to examine factors impacting the timing of onset. Data were collected from medical files of 186 army conscripts, hospitalized with a diagnosis of First Episode Psychosis (FEP) between 2005 and 2014 in the Psychiatric Military Hospital in Athens, Greece. FEP rates were at least 4.5 times higher in the first month of military service, compared with any other month. Earlier FEP onset was associated with rural environment at the time of birth, multiple drug use and service away from home. Psychosocial stress precipitates FEP, particularly in those exposed to other risk factors.

Stress-Dependent Association Between Polygenic Risk for Schizophrenia and Schizotypal Traits in Young Army Recruits

Schizotypal personality traits may increase proneness to psychosis and likely index familial vulnerability to schizophrenia (SZ), implying shared genetic determinants with SZ. Here, we sought to investigate the contribution of common genetic risk variation for SZ on self-reported schizotypy in 2 ethnically homogeneous cohorts of healthy young males during compulsory military service, enrolled in the Athens Study of Proneness and Incidence of Schizophrenia (ASPIS, N = 875) and the Learning on Genetics of Schizophrenia Spectrum study (LOGOS, N = 690). A follow-up psychometric assessment was performed in a sub-sample of the ASPIS (N = 121), 18 months later at military service completion. Polygenic risk scores (PRS) for SZ were derived based on genome-wide association meta-analysis results from the Psychiatric Genomics Consortium. In the ASPIS, higher PRSSZ significantly associated with lower levels of positive (ie, perceptual distortions), disorganization and paranoid facets of schizotypy, whereas no association with negative (ie, interpersonal) facets was noted. Importantly, longitudinal data analysis in the ASPIS subsample revealed that PRSSZ was inversely associated with positive schizotypy at military induction (stressed condition) but not at follow-up (nonstressed condition), providing evidence for environmental rather than SZ-implicated genetic influences. Moreover, consistent with prior reports, PRSSZ was positively correlated with trait anxiety in the LOGOS and additionally the recruits with higher PRSSZ and trait anxiety exhibited attenuated paranoid ideation. Together, these findings do not support an etiological link between increased polygenic liability for SZ and schizotypy, suggesting that psychosocial stress or trait anxiety may impact schizotypal phenotypic expressions among healthy young adults not genetically predisposed to SZ.

Psychotic-like experiences in help-seeking adolescents: Dimensional exploration and association with different forms of bullying victimization - A developmental social psychiatry perspective

BACKGROUND

Psychotic-like experiences (PLEs) are common in the general population and increase the risk of psychotic disorders. Adolescents are a high-risk group of this condition. Stressful events, such as bullying, have a role in the onset of PLEs. This study has several aims: (1) to assess PLEs in adolescents seeking help from a Child and Adolescent Mental Health Service, (2) to assess the association of PLEs with specific bullying victimization and (3) to assess difference in PLEs and victimizations by sex and age.

METHODS

Participants were help-seeking (HS) adolescents initially screened for PLEs. They completed an assessment including characteristics of PLEs and bullying victimization. We paid particular attention to different kinds of PLEs and victimization.

RESULTS

In total, 50 PLE-positive adolescents screened from 324 HS adolescents (15.4%) constituted the sample. Paranoia and verbal bullying were the PLEs and form of victimization most represented, respectively. Verbal bullying was strongly associated with paranoia (odds ratio (OR): 4.40, confidence interval (CI): 2.8-5.9, p < .001). Results remained significant after controlling for confounder (socio-demographic, anxiety, depression and for the latter analysis also other forms of victimization). Furthermore, social manipulation showed a strong association of paranoia and physical bullying with grandiosity. Verbal bullying was also associated with psychotic negative symptoms, but controlling for emotional symptoms and other victimization led to a reduction in the effect. Men were more involved in physical victimization and experienced grandiosity; on the contrary, late adolescents were most involved in social victimization and negative psychotic symptoms Conclusion: PLEs are relevant in HS adolescents. Bullying victimization interacts with the onset of these phenomena. In particular, verbal bullying predicted paranoia onset significantly.

The utility of twins in developmental cognitive neuroscience research: How twins strengthen the ABCD research design

The ABCD twin study will elucidate the genetic and environmental contributions to a wide range of mental and physical health outcomes in children, including substance use, brain and behavioral development, and their interrelationship. Comparisons within and between monozygotic and dizygotic twin pairs, further powered by multiple assessments, provide information about genetic and environmental contributions to developmental associations, and enable stronger tests of causal hypotheses, than do comparisons involving unrelated children. Thus a sub-study of 800 pairs of same-sex twins was embedded within the overall Adolescent Brain and Cognitive Development (ABCD) design. The ABCD Twin Hub comprises four leading centers for twin research in Minnesota, Colorado, Virginia, and Missouri. Each site is enrolling 200 twin pairs, as well as singletons. The twins are recruited from registries of all twin births in each State during 2006-2008. Singletons at each site are recruited following the same school-based procedures as the rest of the ABCD study. This paper describes the background and rationale for the ABCD twin study, the ascertainment of twin pairs and implementation strategy at each site, and the details of the proposed analytic strategies to quantify genetic and environmental influences and test hypotheses critical to the aims of the ABCD study.