Evidence that environmental and genetic risks for psychotic disorder may operate by impacting on connections between core symptoms of perceptual alteration and delusional ideation

Neurodevelopment within the first three years of life does not predict psychotic experiences at age 10: A prospective cohort study

BACKGROUND

Early childhood developmental delays and lower cognitive and motor function have been found to be related to psychotic experiences (PE) in middle childhood. These findings suggest a neurodevelopmental pathway to PE in childhood. This study examined if prospectively assessed neurodevelopment in infancy from birth to age 3 predicted PE at age 10.

METHODS

We included data from the population-based prospective longitudinal cohort COPSAC2010 (n = 700). Parents reported on children milestones starting at 1 week old, language acquisition at 1 and 2 years of age, and children were evaluated on cognition at 2.5 years and general development at 3 years. At age 10, children were clinically assessed regarding PE. We used adjusted logistic regression models to assess the association between developmental within the first years of life and later PE.

RESULTS

We evaluated 593 children at 10 years regarding PE, of which 77 (13 %) reported having experienced PE. We did not find significant associations between early life neurodevelopment and childhood PE. Analyses excluding children with neurodevelopmental diagnosis (i.e, ADHD, autism and tics) yielded similar results.

CONCLUSIONS

Delays in developmental milestones, language acquisition, and cognition during the first 3 years of life were not associated with PE in middle childhood. The findings do not support that childhood PE occurs associated with atypical early neurodevelopment. Given that we report results on one time point PE, clarification of associations with persistent PE are warranted.

Defining Urbanicity in the Context of Psychosis Research: A Qualitative Systematic Literature Review

BACKGROUND AND HYPOTHESIS

Numerous studies have found that being born or raised in urban environments increases the odds of developing psychosis in Northern and Western Europe. However, available research from Southern Europe, Latin America, and Asia has reported null results. A limitation in most studies to date is the inadequate characterization of urban and rural life components that may contribute to varying psychosis risk across regions.

STUDY DESIGN

To deepen our understanding of the different concepts and measures of urbanicity and related factors in psychosis research, we conducted a qualitative systematic literature review extracting information from studies published between 2000 and 2024.

STUDY RESULTS

Sixty-one articles met the inclusion and exclusion criteria and were used in the thematic analysis. The analysis revealed that urbanicity lacked a single, coherent definition across studies and regions. Three major categories of themes were developed from the analysis: (1) Urbanicity comprises several interconnected constructs, (2) Urbanicity measurements vary between countries from the Global North and the Global South, and (3) Urbanicity operates through key neighborhood-level mechanisms.

CONCLUSIONS

Future research on urbanicity and psychosis should consider the potential limitations of urbanicity's conceptualization and operationalization and aim to address these limitations by focusing on contextual, historical, and community-level factors, utilizing locally validated measures, and employing mixed-method designs.

Positive psychotic symptoms as a marker of clinical severity in a transdiagnostic sample of help-seeking adolescents

The present study aimed to examine the association between the presence, number, and type of positive psychotic symptoms (PPS) and clinical severity in adolescent patients. Five hundred-six patients aged 11-17 years were assigned to either the noPPS (n = 341), the delusional beliefs only (del; n = 32), the hallucinations only (hall; n = 80), or the delusional beliefs and hallucinations (del&hall; n = 53) group. Generalized Structural Equation Modeling was applied to identify the best-fitting model representing clinical severity indicated by psychiatric diagnoses, depressivity, personality pathology, non-suicidal self-injury, suicide attempts, perceived stress, and psychosocial impairments, assessed by interviews and questionnaires. The groups were compared concerning the final model's factors. The final model consisted of three factors representing psychopathology and functional impairments, self-harming behavior, and perceived stress (BIC difference to reference model: 103.99). Participants with any PPS scored higher on all factors than the noPPS group (differences in SD: 0.49-1.48). Additionally, the del&hall group scored 1.31 SD higher on psychopathology and functional impairments than the hall group, and 1.16 SD higher on self-harming behavior compared to the del group. Finally, the hall group scored 0.84 SD higher on self-harming behavior than the del group, with no group differences in the other factors. In adolescent patients, the presence of PPS may represent a marker for a more severe form of mental disorder, with hallucinations being indicative of self-harming behavior. Early transdiagnostic assessment of PPS seems indicated as it may inform treatment in the context of clinical staging.

Development of the PSYCHS: Positive SYmptoms and Diagnostic Criteria for the CAARMS Harmonized with the SIPS

AIM

To harmonize two ascertainment and severity rating instruments commonly used for the clinical high risk syndrome for psychosis (CHR-P): the Structured Interview for Psychosis-risk Syndromes (SIPS) and the Comprehensive Assessment of At-Risk Mental States (CAARMS).

METHODS

The initial workshop is described in the companion report from Addington et al. After the workshop, lead experts for each instrument continued harmonizing attenuated positive symptoms and criteria for psychosis and CHR-P through an intensive series of joint videoconferences.

RESULTS

Full harmonization was achieved for attenuated positive symptom ratings and psychosis criteria, and modest harmonization for CHR-P criteria. The semi-structured interview, named Positive SYmptoms and Diagnostic Criteria for the CAARMS Harmonized with the SIPS (PSYCHS), generates CHR-P criteria and severity scores for both CAARMS and SIPS.

CONCLUSIONS

Using the PSYCHS for CHR-P ascertainment, conversion determination, and attenuated positive symptom severity rating will help in comparing findings across studies and in meta-analyses.

Development of the PSYCHS: Positive SYmptoms and Diagnostic Criteria for the CAARMS Harmonized with the SIPS

Aim

To harmonize two ascertainment and severity rating instruments commonly used for the clinical high risk syndrome for psychosis (CHR-P): the Structured Interview for Psychosis-risk Syndromes (SIPS) and the Comprehensive Assessment of At-Risk Mental States (CAARMS).

Methods

The initial workshop is described in the companion report from Addington et al. After the workshop, lead experts for each instrument continued harmonizing attenuated positive symptoms and criteria for psychosis and CHR-P through an intensive series of joint videoconferences.

Results

Full harmonization was achieved for attenuated positive symptom ratings and psychosis criteria, and partial harmonization for CHR-P criteria. The semi-structured interview, named P ositive SY mptoms and Diagnostic Criteria for the C AARMS H armonized with the S IPS (PSYCHS), generates CHR-P criteria and severity scores for both CAARMS and SIPS.

Conclusion

Using the PSYCHS for CHR-P ascertainment, conversion determination, and attenuated positive symptom severity rating will help in comparing findings across studies and in meta-analyses.

Disentangling heterogeneity of psychosis expression in the general population: sex-specific moderation effects of environmental risk factors on symptom networks

BACKGROUND

Psychosis expression in the general population may reflect a behavioral manifestation of the risk for psychotic disorder. It can be conceptualized as an interconnected system of psychotic and affective experiences; a so-called 'symptom network'. Differences in demographics, as well as exposure to adversities and risk factors, may produce substantial heterogeneity in symptom networks, highlighting potential etiological divergence in psychosis risk.

METHODS

To explore this idea in a data-driven way, we employed a novel recursive partitioning approach in the 2007 English National Survey of Psychiatric Morbidity (N = 7242). We sought to identify 'network phenotypes' by explaining heterogeneity in symptom networks through potential moderators, including age, sex, ethnicity, deprivation, childhood abuse, separation from parents, bullying, domestic violence, cannabis use, and alcohol.

RESULTS

Sex was the primary source of heterogeneity in symptom networks. Additional heterogeneity was explained by interpersonal trauma (childhood abuse and domestic violence) in women and domestic violence, cannabis use, ethnicity in men. Among women, especially those exposed to early interpersonal trauma, an affective loading within psychosis may have distinct relevance. Men, particularly those from minority ethnic groups, demonstrated a strong network connection between hallucinatory experiences and persecutory ideation.

CONCLUSION

Symptom networks of psychosis expression in the general population are highly heterogeneous. The structure of symptom networks seems to reflect distinct sex-related adversities, etiologies, and mechanisms of symptom-expression. Disentangling the complex interplay of sex, minority ethnic group status, and other risk factors may help optimize early intervention and prevention strategies in psychosis.

Evidence, and replication thereof, that molecular-genetic and environmental risks for psychosis impact through an affective pathway

BACKGROUND

There is evidence that environmental and genetic risk factors for schizophrenia spectrum disorders are transdiagnostic and mediated in part through a generic pathway of affective dysregulation.

METHODS

We analysed to what degree the impact of schizophrenia polygenic risk (PRS-SZ) and childhood adversity (CA) on psychosis outcomes was contingent on co-presence of affective dysregulation, defined as significant depressive symptoms, in (i) NEMESIS-2 (n = 6646), a representative general population sample, interviewed four times over nine years and (ii) EUGEI (n = 4068) a sample of patients with schizophrenia spectrum disorder, the siblings of these patients and controls.

RESULTS

The impact of PRS-SZ on psychosis showed significant dependence on co-presence of affective dysregulation in NEMESIS-2 [relative excess risk due to interaction (RERI): 1.01, p = 0.037] and in EUGEI (RERI = 3.39, p = 0.048). This was particularly evident for delusional ideation (NEMESIS-2: RERI = 1.74, p = 0.003; EUGEI: RERI = 4.16, p = 0.019) and not for hallucinatory experiences (NEMESIS-2: RERI = 0.65, p = 0.284; EUGEI: -0.37, p = 0.547). A similar and stronger pattern of results was evident for CA (RERI delusions and hallucinations: NEMESIS-2: 3.02, p < 0.001; EUGEI: 6.44, p < 0.001; RERI delusional ideation: NEMESIS-2: 3.79, p < 0.001; EUGEI: 5.43, p = 0.001; RERI hallucinatory experiences: NEMESIS-2: 2.46, p < 0.001; EUGEI: 0.54, p = 0.465).

CONCLUSIONS

The results, and internal replication, suggest that the effects of known genetic and non-genetic risk factors for psychosis are mediated in part through an affective pathway, from which early states of delusional meaning may arise.

Genetic liability in individuals at ultra-high risk of psychosis: A comparison study of 9 psychiatric traits

Individuals at ultra-high risk (UHR) of psychosis are characterised by the emergence of attenuated psychotic symptoms and deterioration in functioning. In view of the high non-psychotic comorbidity and low rates of transition to psychosis, the specificity of the UHR status has been called into question. This study aims to (i) investigate if the UHR construct is associated with the genetic liability of schizophrenia or other psychiatric conditions; (ii) examine the ability of polygenic risk scores (PRS) to discriminate healthy controls from UHR, remission and conversion status. PRS was calculated for 210 youths (nUHR = 102, nControl = 108) recruited as part of the Longitudinal Youth at Risk Study (LYRIKS) using nine psychiatric traits derived from twelve large-scale psychiatric genome-wide association studies as discovery datasets. PRS was also examined to discriminate UHR-Healthy control status, and healthy controls from UHR remission and conversion status. Result indicated that schizophrenia PRS appears to best index the genetic liability of UHR, while trend level associations were observed for depression and cross-disorder PRS. Schizophrenia PRS discriminated healthy controls from UHR (R2 = 7.9%, p = 2.59 x 10-3, OR = 1.82), healthy controls from non-remitters (R2 = 8.1%, p = 4.90 x 10-4, OR = 1.90), and converters (R2 = 7.6%, p = 1.61 x 10-3, OR = 1.82), with modest predictive ability. A trend gradient increase in schizophrenia PRS was observed across categories. The association between schizophrenia PRS and UHR status supports the hypothesis that the schizophrenia polygenic liability indexes the risk for developing psychosis.

What Protective Health Measures Are Americans Taking in Response to COVID-19? Results from the COVID Impact Survey

With the emergence of the novel SARS-CoV-2 and the disease it causes; COVID-19, compliance with/adherence to protective measures is needed. Information is needed on which measures are, or are not, being undertaken. Data collected from the COVID Impact Survey, conducted by the non-partisan and objective research organization NORC at the University of Chicago on April, May, and June of 2020, were analyzed through weighted Quasi-Poisson regression modeling to determine the association of demographics, socioeconomics, and health conditions with protective health measures taken at the individual level in response to COVID-19. The three surveys included data from 18 regional areas including 10 states (CA, CO, FL, LA, MN, MO, MT, NY, OR, and TX) and 8 Metropolitan Statistical Areas (Atlanta, GA; Baltimore, MD; Birmingham, AL; Chicago, IL; Cleveland and Columbus, OH; Phoenix, AZ; and Pittsburgh, PA). Individuals with higher incomes, insurance, higher education levels, large household size, age 60+, females, minorities, those who have asthma, have hypertension, overweight or obese, and those who suffer from mental health issues during the pandemic were significantly more likely to report taking precautionary protective measures relative to their counterparts. Protective measures for the three subgroups with a known relationship to COVID-19 (positive for COVID-19, knowing an individual with COVID-19, and knowing someone who had died from COVID-19) were strongly associated with the protective health measures of washing hands, avoiding public places, and canceling social engagements. This study provides first baseline data on the response to the national COVID-19 pandemic at the individual level in the US. The found heterogeneity in the response to this pandemic by different variables can inform future research and interventions to reduce exposure to the novel SARS-CoV-2 virus.

The interplay between childhood trauma, cognitive biases, and cannabis use on the risk of psychosis in nonclinical young adults in Poland

Background.

Childhood traumatic events are risk factors for psychotic-like experiences (PLEs). However, the mechanisms explaining how trauma may contribute to the development of PLEs are not fully understood. In our study, we investigated whether cannabis use and cognitive biases mediate the relationship between early trauma and PLEs.

Methods.

A total sample of 6,772 young adults (age 26.6 ± 4.7, 2,181 male and 3,433 female) was recruited from the general population to participate in an online survey. We excluded 1,158 individuals due to a self-reported lifetime diagnosis of any mental disorder. The online survey included selected items from the following questionnaires: Traumatic Experience Checklist (TEC, 3 items), Childhood Experience of Care and Abuse Questionnaire (CECA.Q, 3 items), Cannabis Problems Questionnaire (CPQ, 10 items), Davos Assessment of Cognitive Biases Scale (DACOBS-18, 9 items), and Prodromal Questionnaire-16 (PQ-16). Mediation analyses were performed with respect to different categories of traumatic experiences (emotional, physical and sexual abuse as well as emotional neglect).

Results.

Our results showed significant associations of any time of childhood trauma with higher scores of cannabis use (CPQ), cognitive biases (DACOBS), and PLEs (PQ-16) (p < 0.001). We found a direct effect of childhood trauma on PLEs as well as significant indirect effect mediated through cannabis use and cognitive biases. All models tested for the effects of specific childhood adversities revealed similar results. The percentage of variance in PQ-16 scores explained by serial mediation models varied between 32.8 and 34.2% depending on childhood trauma category.

Conclusion.

Cannabis use and cognitive biases play an important mediating role in the relationship between childhood traumatic events and the development of PLEs in a nonclinical young adult population.

Redefining phenotypes to advance psychiatric genetics: Implications from hierarchical taxonomy of psychopathology

Genetic discovery in psychiatry and clinical psychology is hindered by suboptimal phenotypic definitions. We argue that the hierarchical, dimensional, and data-driven classification system proposed by the Hierarchical Taxonomy of Psychopathology (HiTOP) consortium provides a more effective approach to identifying genes that underlie mental disorders, and to studying psychiatric etiology, than current diagnostic categories. Specifically, genes are expected to operate at different levels of the HiTOP hierarchy, with some highly pleiotropic genes influencing higher order psychopathology (e.g., the general factor), whereas other genes conferring more specific risk for individual spectra (e.g., internalizing), subfactors (e.g., fear disorders), or narrow symptoms (e.g., mood instability). We propose that the HiTOP model aligns well with the current understanding of the higher order genetic structure of psychopathology that has emerged from a large body of family and twin studies. We also discuss the convergence between the HiTOP model and findings from recent molecular studies of psychopathology indicating broad genetic pleiotropy, such as cross-disorder SNP-based shared genetic covariance and polygenic risk scores, and we highlight molecular genetic studies that have successfully redefined phenotypes to enhance precision and statistical power. Finally, we suggest how to integrate a HiTOP approach into future molecular genetic research, including quantitative and hierarchical assessment tools for future data-collection and recommendations concerning phenotypic analyses. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

DSM outcomes of psychotic experiences and associated risk factors: 6-year follow-up study in a community-based sample

BACKGROUND

Psychotic experiences (PEs) may predict a range of common, non-psychotic disorders as well as psychotic disorders. In this representative, general population-based cohort study, both psychotic and non-psychotic disorder outcomes of PE were analysed, as were potential moderators.

METHODS

Addresses were contacted in a multistage clustered probability sampling frame covering 11 districts and 302 neighbourhoods at baseline (n = 4011). Participants were interviewed with the Composite International Diagnostic Interview (CIDI) both at baseline and at 6-year follow-up. Participants with PE at baseline were clinically re-interviewed with the SCID-I at follow-up. The role of socio-demographics, characteristics of PE, co-occurrence of mood disorders and family history of mental disorders were tested in the association between baseline PE and follow-up diagnosis.

RESULTS

In the participants with baseline PE, the psychotic disorder diagnosis rate at follow up was 7.0% - much lower than the rates of DSM-IV mood disorders without psychotic features (42.8%) and other non-psychotic disorders (24.1%). Within the group with baseline PE, female sex, lower socio-economic status, co-occurrence of mood disorders, family history of a mental disorder and persistence of PE predicted any follow-up DSM diagnosis. Furthermore, onset of psychotic v. non-psychotic disorder was predicted by younger age (15-30 years), co-presence of delusional and hallucinatory PE and family history of severe mental illness.

CONCLUSION

The outcome of PE appears to be a consequence of baseline severity of multidimensional psychopathology and familial risk. It may be useful to consider PE as a risk indicator that has trans-diagnostic value.

Childhood Trauma in Schizophrenia: Current Findings and Research Perspectives

Schizophrenia is a severe neuropsychiatric disorder with persistence of symptoms throughout adult life in most of the affected patients. This unfavorable course is associated with multiple episodes and residual symptoms, mainly negative symptoms and cognitive deficits. The neural diathesis-stress model proposes that psychosocial stress acts on a pre-existing vulnerability and thus triggers the symptoms of schizophrenia. Childhood trauma is a severe form of stress that renders individuals more vulnerable to developing schizophrenia; neurobiological effects of such trauma on the endocrine system and epigenetic mechanisms are discussed. Childhood trauma is associated with impaired working memory, executive function, verbal learning, and attention in schizophrenia patients, including those at ultra-high risk to develop psychosis. In these patients, higher levels of childhood trauma were correlated with higher levels of attenuated positive symptoms, general symptoms, and depressive symptoms; lower levels of global functioning; and poorer cognitive performance in visual episodic memory end executive functions. In this review, we discuss effects of specific gene variants that interact with childhood trauma in patients with schizophrenia and describe new findings on the brain structural and functional level. Additive effects between childhood trauma and brain-derived neurotrophic factor methionine carriers on volume loss of the hippocampal subregions cornu ammonis (CA)4/dentate gyrus and CA2/3 have been reported in schizophrenia patients. A functional magnetic resonance imaging study showed that childhood trauma exposure resulted in aberrant function of parietal areas involved in working memory and of visual cortical areas involved in attention. In a theory of mind task reflecting social cognition, childhood trauma was associated with activation of the posterior cingulate gyrus, precuneus, and dorsomedial prefrontal cortex in patients with schizophrenia. In addition, decreased connectivity was shown between the posterior cingulate/precuneus region and the amygdala in patients with high levels of physical neglect and sexual abuse during childhood, suggesting that disturbances in specific brain networks underlie cognitive abilities. Finally, we discuss some of the questionnaires that are commonly used to assess childhood trauma and outline possibilities to use recent biostatistical methods, such as machine learning, to analyze the resulting datasets.

Hallucinations in Children and Adolescents: An Updated Review and Practical Recommendations for Clinicians

Hallucinations in children and adolescents are now known to occur on a continuum from healthy to psychopathology-related phenomena. Although hallucinations in young populations are mostly transient, they can cause substantial distress. Despite hallucinations being widely investigated, research so far has had limited implications for clinical practice. The present article has 3 main aims: (1) to review research findings since 2014 (when the last major review of the area was published); (2) to present assessment tools validated to measure hallucinations in children and adolescents; and (3) to discuss therapeutic strategies and clinical issues. We conclude by presenting a tailored care model for clinicians and outline future challenges for research.

Association between family history of mental disorders and outcome in psychotic disorders

We investigated the association of family history of mental disorders, especially psychosis, with occupational and clinical outcome in psychotic disorders in a longitudinal population-based cohort. The Northern Finland Birth Cohort 1986 (n = 9432) was used to gather the data. In total 189 individuals with psychosis were identified by age of 28. The outcome was assessed by using register information regarding occupational activity, disability pension and hospital treatments due to psychiatric cause. Parental psychosis and any psychiatric disorder were used as predictors of outcome. The results showed that presence of any parental psychiatric disorder was associated with higher number of days spent at hospital and higher number of hospitalizations in psychotic disorders, but was not associated with occupational outcome or disability pension. The presence of parental psychosis was not associated with outcome. These findings suggest that the presence of any psychiatric disorder among parents may increase the risk of poorer outcome in psychoses in terms of need of hospitalisations. Based on this study the presence of parental psychosis is not associated with outcome, but the result should be interpreted with caution due to the small sample size and conflict with the results of earlier studies.

The relationship between the level of exposure to stress factors and cannabis in recent onset psychosis

BACKGROUND

There is a lack of studies investigating the dose-response effect of childhood trauma, recent events and cannabis use on recent psychosis. This study aims to determine the relationship between the level of exposure to stress factors and cannabis use with psychosis and to determine the combination effect among these factors in predicting a psychotic disorder.

METHODS

146 recent onset psychotic (ROP) patients and 61 healthy controls were included. Childhood trauma was evaluated using the childhood trauma questionnaire (CTQ) and recent events using the Holmes-Rahe social readjustment scale. The pattern of cannabis use was assessed by a detailed interview. A hierarchical multiple regression was run in order to determine both the cumulative and independent contribution of each factor in predicting a psychotic disorder.

RESULTS

The highest levels of exposure to childhood trauma and cannabis were associated with psychosis while neither low nor high recent event exposure was associated. The combined effect of risk factors yielded a significant association with psychosis (ײ = 86.76, p < .001) explaining the 49% of its variation. ROP were more likely to be exposed to one, two or three environmental factors than HC. Exposed to two or all factors were 7.5-fold and 26.7-fold more likely to have a diagnosis of psychosis, respectively.

CONCLUSIONS

Our study provides evidence for a cumulative and a dose-response effect of environmental factors on recent psychosis. Considering that cannabis use and stress are highly prevalent in the population with psychosis, investigations of their relationships are needed to implement targeted prevention and treatment strategies.

Evidence That Environmental and Familial Risks for Psychosis Additively Impact a Multidimensional Subthreshold Psychosis Syndrome

BACKGROUND

The observed link between positive psychotic experiences (PE) and psychosis spectrum disorder (PSD) may be stronger depending on concomitant presence of PE with other dimensions of psychopathology. We examined whether the effect of common risk factors for PSD on PE is additive and whether the impact of risk factors on the occurrence of PE depends on the co-occurrence of other symptom dimensions (affective dysregulation, negative symptoms, and cognitive alteration).

METHOD

Data from the Netherlands Mental Health Survey and Incidence Study 2 were used. Risk factors included childhood adversity, cannabis use, urbanicity, foreign born, hearing impairment, and family history of affective disorders. Logistic regression models were applied to test (1) the additive effect of risk factors (4 levels) on PE and (2) the moderating effects of symptom dimensions on the association between risk factors (present/absent) and PE, using additive interaction, expressed as the interaction contrast ratio.

RESULTS

Risk factors were additive: the greater the number of risk factors, the greater the odds of PE. Furthermore, concomitant presence of the other symptom dimensions all increased the impact of risk factors on PE. After controlling for age, sex, and education, only affective dysregulation and negative symptoms remained significant moderators; only affective dysregulation remained a significant moderator if all dimensions were adjusted for each other.

CONCLUSIONS

Risk factors may not be directly associated with PE but additively give rise to a multidimensional subthreshold state anticipating the multidimensional clinical syndrome. Early motivational and cognitive impairments in the context of PE may be reducible to affective dysregulation.

Network Approach to Understanding Emotion Dynamics in Relation to Childhood Trauma and Genetic Liability to Psychopathology: Replication of a Prospective Experience Sampling Analysis

Background: The network analysis of intensive time series data collected using the Experience Sampling Method (ESM) may provide vital information in gaining insight into the link between emotion regulation and vulnerability to psychopathology. The aim of this study was to apply the network approach to investigate whether genetic liability (GL) to psychopathology and childhood trauma (CT) are associated with the network structure of the emotions "cheerful," "insecure," "relaxed," "anxious," "irritated," and "down"-collected using the ESM method. Methods: Using data from a population-based sample of twin pairs and siblings (704 individuals), we examined whether momentary emotion network structures differed across strata of CT and GL. GL was determined empirically using the level of psychopathology in monozygotic and dizygotic co-twins. Network models were generated using multilevel time-lagged regression analysis and were compared across three strata (low, medium, and high) of CT and GL, respectively. Permutations were utilized to calculate p values and compare regressions coefficients, density, and centrality indices. Regression coefficients were presented as connections, while variables represented the nodes in the network. Results: In comparison to the low GL stratum, the high GL stratum had significantly denser overall (p = 0.018) and negative affect network density (p < 0.001). The medium GL stratum also showed a directionally similar (in-between high and low GL strata) but statistically inconclusive association with network density. In contrast to GL, the results of the CT analysis were less conclusive, with increased positive affect density (p = 0.021) and overall density (p = 0.042) in the high CT stratum compared to the medium CT stratum but not to the low CT stratum. The individual node comparisons across strata of GL and CT yielded only very few significant results, after adjusting for multiple testing. Conclusions: The present findings demonstrate that the network approach may have some value in understanding the relation between established risk factors for mental disorders (particularly GL) and the dynamic interplay between emotions. The present finding partially replicates an earlier analysis, suggesting it may be instructive to model negative emotional dynamics as a function of genetic influence.

Moving Forward: Challenges and Directions for Psychopathological Network Theory and Methodology

Since the introduction of mental disorders as networks of causally interacting symptoms, this novel framework has received considerable attention. The past years have resulted in over 40 scientific publications and numerous conference symposia and workshops. Now is an excellent moment to take stock of the network approach: What are its most fundamental challenges, and what are potential ways forward in addressing them? After a brief conceptual introduction, we first discuss challenges to network theory: (1) What is the validity of the network approach beyond some commonly investigated disorders such as major depression? (2) How do we best define psychopathological networks and their constituent elements? And (3) how can we gain a better understanding of the causal nature and real-life underpinnings of associations among symptoms? Next, after a short technical introduction to network modeling, we discuss challenges to network methodology: (4) heterogeneity of samples studied with network analytic models, and (5) a lurking replicability crisis in this strongly data-driven and exploratory field. Addressing these challenges may propel the network approach from its adolescence into adulthood and promises advances in understanding psychopathology both at the nomothetic and idiographic level.

Association between family history of psychiatric disorders and long-term outcome in schizophrenia - The Northern Finland Birth Cohort 1966 study

Family history of psychiatric disorders has been associated with impaired outcome in schizophrenia, but very few studies have investigated its long-term social and occupational outcome. We investigated the association of family history of psychiatric disorders, especially psychosis, with long-term social, occupational, clinical and global outcome in schizophrenia. The study sample comprises of the Northern Finland Birth Cohort 1966. Cohort members with psychosis were detected by Finnish national registers. Altogether 69 individuals with schizophrenia spectrum diagnosis participated, mean age 43, after on average 17 years since onset of illness. The information regarding family history of psychiatric disorders were gathered from registers and interviews. A Strauss-Carpenter Outcome Scale, PANSS and SOFAS were conducted to assess the outcome. Results showed that the family history of any psychiatric disorder was associated with more severe positive and emotional symptoms in PANSS. The family history of psychosis was not associated with outcomes. These findings suggest that family history of psychiatric disorders has a small association with outcome in schizophrenia. Despite family history of psychosis being a strong risk factor for schizophrenia, after years of illness it does not seem to affect outcome.

Exposure to environmental factors increases connectivity between symptom domains in the psychopathology network

BACKGROUND

We investigated to what degree environmental exposure (childhood trauma, urbanicity, cannabis use, and discrimination) impacts symptom connectivity using both continuous and categorical measures of psychopathology.

METHODS

Outcomes were continuous symptom dimensions of self-reported psychopathology using the Self-report Symptom Checklist-90-R in 3021 participants from The Early Developmental Stages of the Psychopathology (EDSP) study and binary DSM-III-R categories of mental disorders and a binary measure of psychotic symptoms in 7076 participants from The Netherlands Mental Health Survey and Incidence Study (NEMESIS-1). For each symptom dimension in the EDSP and mental disorder in the NEMESIS-1 as the dependent variable, regression analyses were carried out including each of the remaining symptom dimensions/mental disorders and its interaction with cumulative environmental risk load (the sum score of environmental exposures) as independent variables.

RESULTS

All symptom dimensions in the EDSP and related diagnostic categories in the NEMESIS-1 were strongly associated with each other, and environmental exposures increased the degree of symptom connectivity in the networks in both cohorts.

CONCLUSIONS

Our findings showing strong connectivity across symptom dimensions and related binary diagnostic constructs in two independent population cohorts provide further evidence for the conceptualization of psychopathology as a contextually sensitive network of mutually interacting symptoms.

Psychotic-Like Experiences and Psychological Distress: The Role of Resilience

BACKGROUND

The occurrence of psychotic-like experiences and schizotypal features in the general nonclinical population may imply a connection with psychosis-related liability.

OBJECTIVE

This study was designed to examine the role of resilience in the relationship of hallucination and delusion-like experiences and schizotypal features to psychological distress in a nonclinical sample.

DESIGN

The study sample (n = 432 university students) was selected through a stratified cluster sampling procedure, and measures of hallucination proneness, delusion proneness, schizotypal personality, and psychological distress were administered.

RESULTS

While all three indices of psychotic-like experiences correlated with one another, only hallucination proneness and schizotypal personality features correlated with psychological distress and only schizotypal traits correlated with resilience. Schizotypy was found to have an indirect effect on distress through resilience.

CONCLUSIONS

Findings imply the possibility of two types of schizotypy, with high or low resilience. It appears that schizotypes with low resilience may be susceptible to adversity and mental disorders, while high resilience may be protective.

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.

Network analysis of substance abuse and dependence symptoms

BACKGROUND

The DSM uses one set of abuse and dependence criteria to assess multiple substance use disorders (SUDs). Most SUD research aggregates across these symptoms to study the behavior of SUD as a static construct. We use an alternative approach that conceptualizes symptoms as directly interacting variables in psychopathological networks. We apply network models to symptom-level data to investigate the unique roles of individual symptoms and their interactions in SUD.

METHODS

We analyzed 11 DSM III-R/IV abuse and dependence criteria in a sample of 2405 adult twins who reported use of at least one illicit substance six or more times from the Virginia Adult Twin Study of Psychiatric and Substance Use Disorders (VATSPSUD). We estimated a symptom network for each substance class as well as a global network collapsed across all substance classes. We examined similarities and differences across the 6 networks in terms of symptom-to-symptom connections and symptom centrality.

RESULTS

The global network model revealed several interesting symptom connections, such as a strong predictive relation between tolerance and more-than-planned substance use. The most central symptom was using a drug more than planned. In addition, several interesting differences across substances emerged, both in the strength of symptom connections as well as the centrality of symptoms to each network.

CONCLUSIONS

When analyzed as networks, abuse and dependence symptoms do not function equivalently across illicit substance classes. These findings suggest the value of analyzing individual symptoms and their associations to gain new insight into the mechanisms of SUD.

Dysfunctional meta-cognitive beliefs mediate the relation between temperament traits and hallucination-proneness in non-clinical population

We investigated whether dysfunctional metacognitive beliefs (negative beliefs about uncontrollability and danger of thoughts) mediate the relationship between temperamental characteristics of behavior and hallucinatory-like experiences in healthy subjects (n=137). Our analyses showed that four temperamental traits (emotional reactivity, perseveration, endurance and briskness) were mediated by negative beliefs about uncontrollability and danger of thoughts in relation to hallucination proneness. Our research tentatively suggests that temperament affects hallucination proneness via metacognition.

The CCC2000 Birth Cohort Study of Register-Based Family History of Mental Disorders and Psychotic Experiences in Offspring

Psychotic experiences (PE) in individuals of the general population are hypothesized to mark the early expression of the pathology underlying psychosis. This notion of PE as an intermediate phenotype is based on the premise that PE share genetic liability with psychosis. We examined whether PE in childhood was predicted by a family history of mental disorder with psychosis rather than a family history of nonpsychotic mental disorder and whether this association differed by severity of PE. The study examined data on 1632 children from a general population birth cohort assessed at age 11-12 years by use of a semistructured interview covering 22 psychotic symptoms. The Danish national registers were linked to describe the complete family history of hospital-based psychiatric diagnoses. Uni- and multivariable logistic regressions were used to test whether a family history of any mental disorder with psychosis, or of nonpsychotic mental disorder, vs no diagnoses was associated with increased risk of PE in offspring (hierarchical exposure variable). The occurrence of PE in offspring was significantly associated with a history of psychosis among the first-degree relatives (adjusted relative risk [RR] = 3.29, 95% CI: 1.82-5.93). The risk increased for combined hallucinations and delusions (adjusted RR = 5.90, 95% CI: 2.64-13.16). A history of nonpsychotic mental disorders in first-degree relatives did not contribute to the risk of PE in offspring nor did any mental disorder among second-degree relatives. Our findings support the notion of PE as a vulnerability marker of transdiagnostic psychosis. The effect of psychosis in first-degree relatives may operate through shared genetic and environmental factors.

Problematic assumptions have slowed down depression research: why symptoms, not syndromes are the way forward

Major depression (MD) is a highly heterogeneous diagnostic category. Diverse symptoms such as sad mood, anhedonia, and fatigue are routinely added to an unweighted sum-score, and cutoffs are used to distinguish between depressed participants and healthy controls. Researchers then investigate outcome variables like MD risk factors, biomarkers, and treatment response in such samples. These practices presuppose that (1) depression is a discrete condition, and that (2) symptoms are interchangeable indicators of this latent disorder. Here I review these two assumptions, elucidate their historical roots, show how deeply engrained they are in psychological and psychiatric research, and document that they contrast with evidence. Depression is not a consistent syndrome with clearly demarcated boundaries, and depression symptoms are not interchangeable indicators of an underlying disorder. Current research practices lump individuals with very different problems into one category, which has contributed to the remarkably slow progress in key research domains such as the development of efficacious antidepressants or the identification of biomarkers for depression. The recently proposed network framework offers an alternative to the problematic assumptions. MD is not understood as a distinct condition, but as heterogeneous symptom cluster that substantially overlaps with other syndromes such as anxiety disorders. MD is not framed as an underlying disease with a number of equivalent indicators, but as a network of symptoms that have direct causal influence on each other: insomnia can cause fatigue which then triggers concentration and psychomotor problems. This approach offers new opportunities for constructing an empirically based classification system and has broad implications for future research.