Genome-wide association analyses identify 95 risk loci and provide insights into the neurobiology of post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) genetics are characterized by lower discoverability than most other psychiatric disorders. The contribution to biological understanding from previous genetic studies has thus been limited. We performed a multi-ancestry meta-analysis of genome-wide association studies across 1,222,882 individuals of European ancestry (137,136 cases) and 58,051 admixed individuals with African and Native American ancestry (13,624 cases). We identified 95 genome-wide significant loci (80 new). Convergent multi-omic approaches identified 43 potential causal genes, broadly classified as neurotransmitter and ion channel synaptic modulators (for example, GRIA1, GRM8 and CACNA1E), developmental, axon guidance and transcription factors (for example, FOXP2, EFNA5 and DCC), synaptic structure and function genes (for example, PCLO, NCAM1 and PDE4B) and endocrine or immune regulators (for example, ESR1, TRAF3 and TANK). Additional top genes influence stress, immune, fear and threat-related processes, previously hypothesized to underlie PTSD neurobiology. These findings strengthen our understanding of neurobiological systems relevant to PTSD pathophysiology, while also opening new areas for investigation.

Association between relative age at school and persistence of ADHD in prospective studies: an individual participant data meta-analysis

BACKGROUND

The youngest children in a school class are more likely than the oldest to be diagnosed with ADHD, but this relative age effect is less frequent in older than in younger school-grade children. However, no study has explored the association between relative age and the persistence of ADHD diagnosis at older ages. We aimed to quantify the association between relative age and persistence of ADHD at older ages.

METHODS

For this meta-analysis, we searched MEDLINE, Embase, CINAHL, PsycINFO, and PubPsych up to April 1, 2022, with terms related to "cohort" and "ADHD" with no date, publication type, or language restrictions. We gathered individual participant data from prospective cohorts that included at least ten children identified with ADHD before age 10 years. ADHD was defined by either a clinical diagnosis or symptoms exceeding clinical cutoffs. Relative age was recorded as the month of birth in relation to the school-entry cutoff date. Study authors were invited to share raw data or to apply a script to analyse data locally and generate anonymised results. Our outcome was ADHD status at a diagnostic reassessment, conducted at least 4 years after the initial assessment and after age 10 years. No information on sex, gender, or ethnicity was collected. We did a two-stage random-effects individual participant data meta-analysis to assess the association of relative age with persistence of ADHD at follow-up. This study was registered with PROSPERO, CRD42020212650.

FINDINGS

Of 33 119 studies generated by our search, we identified 130 eligible unique studies and were able to gather individual participant data from 57 prospective studies following up 6504 children with ADHD. After exclusion of 16 studies in regions with a flexible school entry system that did not allow confident linkage of birthdate to relative age, the primary analysis included 41 studies in 15 countries following up 4708 children for a period of 4 to 33 years. We found that younger relative age was not statistically significantly associated with ADHD persistence at follow-up (odds ratio 1·02, 95% CI 0·99-1·06; p=0·19). We observed statistically significant heterogeneity in our model (Q=75·82, p=0·0011, I2=45%). Participant-level sensitivity analyses showed similar results in cohorts with a robust relative age effect at baseline and when restricting to cohorts involving children with a clinical diagnosis of ADHD or with a follow-up duration of more than 10 years.

INTERPRETATION

The diagnosis of ADHD in younger children in a class is no more likely to be disconfirmed over time than that of older children in the class. One interpretation is that the relative age effect decreases the likelihood of children of older relative age receiving a diagnosis of ADHD, and another is that assigning a diagnostic label of ADHD leads to unexplored carryover effects of the initial diagnosis that persist over time. Future studies should be conducted to explore these interpretations further.

FUNDING

None.

Discovery of 95 PTSD loci provides insight into genetic architecture and neurobiology of trauma and stress-related disorders

Posttraumatic stress disorder (PTSD) genetics are characterized by lower discoverability than most other psychiatric disorders. The contribution to biological understanding from previous genetic studies has thus been limited. We performed a multi-ancestry meta-analysis of genome-wide association studies across 1,222,882 individuals of European ancestry (137,136 cases) and 58,051 admixed individuals with African and Native American ancestry (13,624 cases). We identified 95 genome-wide significant loci (80 novel). Convergent multi-omic approaches identified 43 potential causal genes, broadly classified as neurotransmitter and ion channel synaptic modulators (e.g., GRIA1, GRM8, CACNA1E ), developmental, axon guidance, and transcription factors (e.g., FOXP2, EFNA5, DCC ), synaptic structure and function genes (e.g., PCLO, NCAM1, PDE4B ), and endocrine or immune regulators (e.g., ESR1, TRAF3, TANK ). Additional top genes influence stress, immune, fear, and threat-related processes, previously hypothesized to underlie PTSD neurobiology. These findings strengthen our understanding of neurobiological systems relevant to PTSD pathophysiology, while also opening new areas for investigation.

Deviations from a typical development of the cerebellum in youth are associated with psychopathology, executive functions and educational outcomes

BACKGROUND

Understanding deviations from typical brain development is a promising approach to comprehend pathophysiology in childhood and adolescence. We investigated if cerebellar volumes different than expected for age and sex could predict psychopathology, executive functions and academic achievement.

METHODS

Children and adolescents aged 6-17 years from the Brazilian High-Risk Cohort Study for Mental Conditions had their cerebellar volume estimated using Multiple Automatically Generated Templates from T1-weighted images at baseline (n = 677) and at 3-year follow-up (n = 447). Outcomes were assessed using the Child Behavior Checklist and standardized measures of executive functions and school achievement. Models of typically developing cerebellum were based on a subsample not exposed to risk factors and without mental-health conditions (n = 216). Deviations from this model were constructed for the remaining individuals (n = 461) and standardized variation from age and sex trajectory model was used to predict outcomes in cross-sectional, longitudinal and mediation analyses.

RESULTS

Cerebellar volumes higher than expected for age and sex were associated with lower externalizing specific factor and higher executive functions. In a longitudinal analysis, deviations from typical development at baseline predicted inhibitory control at follow-up, and cerebellar deviation changes from baseline to follow-up predicted changes in reading and writing abilities. The association between deviations in cerebellar volume and academic achievement was mediated by inhibitory control.

CONCLUSIONS

Deviations in the cerebellar typical development are associated with outcomes in youth that have long-lasting consequences. This study highlights both the potential of typical developing models and the important role of the cerebellum in mental health, cognition and education.

Volume of subcortical brain regions in social anxiety disorder: mega-analytic results from 37 samples in the ENIGMA-Anxiety Working Group

There is limited convergence in neuroimaging investigations into volumes of subcortical brain regions in social anxiety disorder (SAD). The inconsistent findings may arise from variations in methodological approaches across studies, including sample selection based on age and clinical characteristics. The ENIGMA-Anxiety Working Group initiated a global mega-analysis to determine whether differences in subcortical volumes can be detected in adults and adolescents with SAD relative to healthy controls. Volumetric data from 37 international samples with 1115 SAD patients and 2775 controls were obtained from ENIGMA-standardized protocols for image segmentation and quality assurance. Linear mixed-effects analyses were adjusted for comparisons across seven subcortical regions in each hemisphere using family-wise error (FWE)-correction. Mixed-effects d effect sizes were calculated. In the full sample, SAD patients showed smaller bilateral putamen volume than controls (left: d = -0.077, pFWE = 0.037; right: d = -0.104, pFWE = 0.001), and a significant interaction between SAD and age was found for the left putamen (r = -0.034, pFWE = 0.045). Smaller bilateral putamen volumes (left: d = -0.141, pFWE < 0.001; right: d = -0.158, pFWE < 0.001) and larger bilateral pallidum volumes (left: d = 0.129, pFWE = 0.006; right: d = 0.099, pFWE = 0.046) were detected in adult SAD patients relative to controls, but no volumetric differences were apparent in adolescent SAD patients relative to controls. Comorbid anxiety disorders and age of SAD onset were additional determinants of SAD-related volumetric differences in subcortical regions. To conclude, subtle volumetric alterations in subcortical regions in SAD were detected. Heterogeneity in age and clinical characteristics may partly explain inconsistencies in previous findings. The association between alterations in subcortical volumes and SAD illness progression deserves further investigation, especially from adolescence into adulthood.

Disentangling the influences of parental genetics on offspring's cognition, education, and psychopathology via genetic and phenotypic pathways

BACKGROUND

Specific pathways of intergenerational transmission of behavioral traits remain unclear. Here, we aim to investigate how parental genetics influence offspring cognition, educational attainment, and psychopathology in youth.

METHODS

Participants for the discovery sample were 2,189 offspring (aged 6-14 years), 1898 mothers and 1,017 fathers who underwent genotyping, psychiatric, and cognitive assessments. We calculated polygenic scores (PGS) for cognition, educational attainment, attention-deficit hyperactivity disorder (ADHD), and schizophrenia for the trios. Phenotypes studied included educational and cognitive measures, ADHD and psychotic symptoms. We used a stepwise approach and multiple mediation models to analyze the effect of parental PGS on offspring traits via offspring PGS and parental phenotype. Significant results were replicated in a sample of 1,029 adolescents, 363 mothers, and 307 fathers.

RESULTS

Maternal and paternal PGS for cognition influenced offspring general intelligence and executive function via offspring PGS (genetic pathway) and parental education (phenotypic pathway). Similar results were found for parental PGS for educational attainment and offspring reading and writing skills. These pathways fully explained associations between parental PGS and offspring phenotypes, without residual direct association. Associations with maternal, but not paternal, PGS were replicated. No associations were found between parental PGS for psychopathology and offspring specific symptoms.

CONCLUSIONS

Our findings indicate that parental genetics influences offspring cognition and educational attainment by genetic and phenotypic pathways, suggesting the expression of parental phenotypes partially explain the association between parental genetic risk and offspring outcomes. Multiple mediations might represent an effective approach to disentangle distinct pathways for intergenerational transmission of behavioral traits.

Genetic variants associated with longitudinal changes in brain structure across the lifespan

Human brain structure changes throughout the lifespan. Altered brain growth or rates of decline are implicated in a vast range of psychiatric, developmental and neurodegenerative diseases. In this study, we identified common genetic variants that affect rates of brain growth or atrophy in what is, to our knowledge, the first genome-wide association meta-analysis of changes in brain morphology across the lifespan. Longitudinal magnetic resonance imaging data from 15,640 individuals were used to compute rates of change for 15 brain structures. The most robustly identified genes GPR139, DACH1 and APOE are associated with metabolic processes. We demonstrate global genetic overlap with depression, schizophrenia, cognitive functioning, insomnia, height, body mass index and smoking. Gene set findings implicate both early brain development and neurodegenerative processes in the rates of brain changes. Identifying variants involved in structural brain changes may help to determine biological pathways underlying optimal and dysfunctional brain development and aging.

Brain charts for the human lifespan

Over the past few decades, neuroimaging has become a ubiquitous tool in basic research and clinical studies of the human brain. However, no reference standards currently exist to quantify individual differences in neuroimaging metrics over time, in contrast to growth charts for anthropometric traits such as height and weight1. Here we assemble an interactive open resource to benchmark brain morphology derived from any current or future sample of MRI data ( http://www.brainchart.io/ ). With the goal of basing these reference charts on the largest and most inclusive dataset available, acknowledging limitations due to known biases of MRI studies relative to the diversity of the global population, we aggregated 123,984 MRI scans, across more than 100 primary studies, from 101,457 human participants between 115 days post-conception to 100 years of age. MRI metrics were quantified by centile scores, relative to non-linear trajectories2 of brain structural changes, and rates of change, over the lifespan. Brain charts identified previously unreported neurodevelopmental milestones3, showed high stability of individuals across longitudinal assessments, and demonstrated robustness to technical and methodological differences between primary studies. Centile scores showed increased heritability compared with non-centiled MRI phenotypes, and provided a standardized measure of atypical brain structure that revealed patterns of neuroanatomical variation across neurological and psychiatric disorders. In summary, brain charts are an essential step towards robust quantification of individual variation benchmarked to normative trajectories in multiple, commonly used neuroimaging phenotypes.

Mental health conditions in Lesbian, Gay, Bisexual, Transgender, Queer and Asexual youth in Brazil: A call for action

BACKGROUND

Lesbian, Gay, Bisexual, Transgender, Queer, and Asexual (LGBTQA+) youth have a greater chance of experiencing stressful life events when compared to cisgender heterosexual peers, which can lead to mental health problems. We aimed to estimate the prevalence of mental disorders among LGBTQA+ youths from two large cities in Brazil.

METHODS

Participants were 13-22 years old youths from the 3rd wave of the Brazilian High-Risk Cohort for Psychiatric Disorders (n = 1475). Mental disorders were assessed using the Development and Well-Being Behavior Assessment. Sexual orientation and gender identity were assessed using a self-report confidential questionnaire. Data were analyzed through logistic regressions (adjusting for sociodemographic) using sampling weights to account for attrition and our oversampling high-risk design.

RESULTS

15.18% of the sample described themselves as LGBTQA+. The LGBTQA+ group presented higher rates of anxiety disorders (30.14% vs. 13.37%; OR = 3.37; 95%CI:2.51-4.50), depressive disorders (27.75% vs. 15.34%; OR = 2.17; 95%CI:1.60-2.93) and post-traumatic stress disorder (4.98% vs. 2.25%; OR = 4.20; 95%CI:2.24-7.82), if compared with the cisgender heterosexual group. No difference was found for conduct disorders (2.97% vs. 5.21%; OR = 0.82; 95%CI:0.35-1.65) or attention deficit hyperactivity disorder (5.92% vs. 3.28%; OR = 1.56; 95%CI:0.83-2.79).

LIMITATIONS

Although recruitment was performed at 57 schools in the two cities, sampling was non-probabilistic and included only urban areas, which might bias prevalence estimates and group comparisons.

CONCLUSIONS

Our results elucidate the mental health disparities between LGBTQA+ people and cisgender heterosexuals in Brazil. It highlights the need to promote the inclusion of this population in policy formulation and support actions to mitigate the suffering related to sexual orientation and gender identity.

ENIGMA-anxiety working group: Rationale for and organization of large-scale neuroimaging studies of anxiety disorders

Anxiety disorders are highly prevalent and disabling but seem particularly tractable to investigation with translational neuroscience methodologies. Neuroimaging has informed our understanding of the neurobiology of anxiety disorders, but research has been limited by small sample sizes and low statistical power, as well as heterogenous imaging methodology. The ENIGMA-Anxiety Working Group has brought together researchers from around the world, in a harmonized and coordinated effort to address these challenges and generate more robust and reproducible findings. This paper elaborates on the concepts and methods informing the work of the working group to date, and describes the initial approach of the four subgroups studying generalized anxiety disorder, panic disorder, social anxiety disorder, and specific phobia. At present, the ENIGMA-Anxiety database contains information about more than 100 unique samples, from 16 countries and 59 institutes. Future directions include examining additional imaging modalities, integrating imaging and genetic data, and collaborating with other ENIGMA working groups. The ENIGMA consortium creates synergy at the intersection of global mental health and clinical neuroscience, and the ENIGMA-Anxiety Working Group extends the promise of this approach to neuroimaging research on anxiety disorders.

Mega-analysis methods in ENIGMA: The experience of the generalized anxiety disorder working group

The ENIGMA group on Generalized Anxiety Disorder (ENIGMA-Anxiety/GAD) is part of a broader effort to investigate anxiety disorders using imaging and genetic data across multiple sites worldwide. The group is actively conducting a mega-analysis of a large number of brain structural scans. In this process, the group was confronted with many methodological challenges related to study planning and implementation, between-country transfer of subject-level data, quality control of a considerable amount of imaging data, and choices related to statistical methods and efficient use of resources. This report summarizes the background information and rationale for the various methodological decisions, as well as the approach taken to implement them. The goal is to document the approach and help guide other research groups working with large brain imaging data sets as they develop their own analytic pipelines for mega-analyses.

Mental health interventions following COVID-19 and other coronavirus infections: a systematic review of current recommendations and meta-analysis of randomized controlled trials

OBJECTIVE

To review the most common mental health strategies aimed at alleviating and/or preventing mental health problems in individuals during the coronavirus disease 2019 (COVID-19) and other coronavirus pandemics.

METHODS

We conducted a systematic review of the literature assessing three databases (PubMed, SCOPUS, and PsycINFO). A meta-analysis was performed with data from randomized controlled trials (RCTs). For non-RCT studies, a critical description of recommendations was performed.

RESULTS

From a total of 2,825 articles, 125 were included. Of those, three RCTs were included in the meta-analysis. The meta-analysis revealed that the interventions promoted better overall mental health outcomes as compared to control groups (standardized mean difference [SMD] = 0.87 [95%CI 0.33-1.41], p < 0.001, I2 = 69.2%), but did not specifically improve anxiety (SMD = 0.98 [95%CI -0.17 to 2.13], p > 0.05; I2 = 36.8%). Concerning the systematic review, we found a large body of scientific literature proposing recommendations involving psychological/psychiatric interventions, self-care, education, governmental programs, and the use of technology and media.

CONCLUSIONS

We found a large body of expert recommendations that may help health practitioners, institutional and governmental leaders, and the general population cope with mental health issues during a pandemic or a crisis period. However, most articles had a low level of evidence, stressing the need for more studies with better design (especially RCTs) investigating potential mental health interventions during COVID-19.

PROSPERO REGISTRATION

CRD42020190212.

Cortical and subcortical brain structure in generalized anxiety disorder: findings from 28 research sites in the ENIGMA-Anxiety Working Group

The goal of this study was to compare brain structure between individuals with generalized anxiety disorder (GAD) and healthy controls. Previous studies have generated inconsistent findings, possibly due to small sample sizes, or clinical/analytic heterogeneity. To address these concerns, we combined data from 28 research sites worldwide through the ENIGMA-Anxiety Working Group, using a single, pre-registered mega-analysis. Structural magnetic resonance imaging data from children and adults (5-90 years) were processed using FreeSurfer. The main analysis included the regional and vertex-wise cortical thickness, cortical surface area, and subcortical volume as dependent variables, and GAD, age, age-squared, sex, and their interactions as independent variables. Nuisance variables included IQ, years of education, medication use, comorbidities, and global brain measures. The main analysis (1020 individuals with GAD and 2999 healthy controls) included random slopes per site and random intercepts per scanner. A secondary analysis (1112 individuals with GAD and 3282 healthy controls) included fixed slopes and random intercepts per scanner with the same variables. The main analysis showed no effect of GAD on brain structure, nor interactions involving GAD, age, or sex. The secondary analysis showed increased volume in the right ventral diencephalon in male individuals with GAD compared to male healthy controls, whereas female individuals with GAD did not differ from female healthy controls. This mega-analysis combining worldwide data showed that differences in brain structure related to GAD are small, possibly reflecting heterogeneity or those structural alterations are not a major component of its pathophysiology.

Obsessive-Compulsive Symptoms, Polygenic Risk Score, and Thalamic Development in Children From the Brazilian High-Risk Cohort for Mental Conditions (BHRCS)

Background: Thalamic volume measures have been linked to obsessive-compulsive disorder (OCD) in children and adolescents. However, it is unclear if alterations in thalamic volumes occur before or after symptom onset and if there is a relation to the presence of sub-clinical obsessive-compulsive symptoms (OCS). Here, we explore the relationship between OCS and the rate of thalamic volume change in a cohort of children and youth at high risk to develop a mental disorder. A secondary aim was to determine if there is a relationship between OCS and the individual's OCD polygenic risk score (OCD-PRS) and between the rate of thalamic volume change and the OCD-PRS. Methods: The sample included 378 children enrolled in the longitudinal Brazilian High-Risk Cohort for Mental Conditions. Participants were assessed for OCS and the symmetrized percent change (SPC) of thalamic volume across two time-points separated by 3 years, along with the OCD-PRS. Zero-altered negative binomial models were used to analyze the relationship between OCS and thalamic SPC. Multiple linear regressions were used to examine the relationship between thalamic SPC and OCD-PRS. Results: A significant relationship between OCS and the right thalamus SPC (p = 0.042) was found. There was no significant relationship between changes in thalamic volume SPC and OCD-PRS. Conclusions: The findings suggest that changes in the right thalamic volume over the course of 3 years in children may be associated to OCS. Future studies are needed to confirm these results and further characterize the specific nature of OCS symptoms associated with thalamic volumes.

Lowering costs for large-scale screening in psychosis: a systematic review and meta-analysis of performance and value of information for speech-based psychiatric evaluation

OBJECTIVE

Obstacles for computational tools in psychiatry include gathering robust evidence and keeping implementation costs reasonable. We report a systematic review of automated speech evaluation for the psychosis spectrum and analyze the value of information for a screening program in a healthcare system with a limited number of psychiatrists (Maputo, Mozambique).

METHODS

Original studies on speech analysis for forecasting of conversion in individuals at clinical high risk (CHR) for psychosis, diagnosis of manifested psychotic disorder, and first-episode psychosis (FEP) were included in this review. Studies addressing non-verbal components of speech (e.g., pitch, tone) were excluded.

RESULTS

Of 168 works identified, 28 original studies were included. Valuable speech features included direct measures (e.g., relative word counting) and mathematical embeddings (e.g.: word-to-vector, graphs). Accuracy estimates reported for schizophrenia diagnosis and CHR conversion ranged from 71 to 100% across studies. Studies used structured interviews, directed tasks, or prompted free speech. Directed-task protocols were faster while seemingly maintaining performance. The expected value of perfect information is USD 9.34 million. Imperfect tests would nevertheless yield high value.

CONCLUSION

Accuracy for screening and diagnosis was high. Larger studies are needed to enhance precision of classificatory estimates. Automated analysis presents itself as a feasible, low-cost method which should be especially useful for regions in which the physician pool is insufficient to meet demand.

Assessment of Neurobiological Mechanisms of Cortical Thinning During Childhood and Adolescence and Their Implications for Psychiatric Disorders

Importance

Many psychiatric disorders can be conceptualized as disorders of brain maturation during childhood and adolescence. Discovering the neurobiological underpinnings of brain maturation may elucidate molecular pathways of vulnerability and resilience to such disorders.

Objective

To investigate the underlying neurobiological mechanisms of age-associated cortical thinning during maturation and their implications for psychiatric disorders.

Design, Setting, and Participants

This multicohort analysis used data from 3 community-based studies. The Saguenay Youth Study provided data from 1024 adolescents who were recruited at a single site in Quebec, Canada. The IMAGEN cohort provided data from 1823 participants who were recruited in 8 European cities. The Brazil High Risk Cohort Study for the Development of Childhood Psychiatric Disorders provided data from 815 participants who were recruited in 2 Brazilian cities. Cortical thickness was estimated from the results of magnetic resonance imaging (MRI) scans, and age-associated cortical thinning was estimated in 34 cortical regions. Gene expression from the Allen Human Brain Atlas was aligned with the same regions. Similarities in the interregional profiles of gene expression and the profiles of age-associated cortical thinning were measured. The involvement of dendrites, dendritic spines, and myelin was tested using 3 gene panels. Enrichment for genes associated with psychiatric disorders was tested among the genes associated with thinning and their coexpression networks. Data analysis was conducted between March and October 2019.

Main Outcomes and Measures

MRI-derived estimates of age-associated cortical thinning and gene expression in 34 cortical regions.

Results

A total of 3596 individuals aged 9 to 21 years were included in this study. Of those, 1803 participants (50.1%) were female, and the mean (SD) age was 15.2 (2.6) years. Interregional profiles of age-associated cortical thinning were associated with interregional gradients in the expression of genes associated with dendrites, dendritic spines, and myelin; the variance in thinning explained by the gene panels across different points ranged from 0.45% to 10.55% for the dendrite panel, 0.00% to 9.98% for the spine panel, and 0.19% to 26.39% for the myelin panel. These genes and their coexpression networks were enriched for genes associated with several psychiatric disorders.

Conclusions and Relevance

In this study, genetic similarity between interregional variation in cortical thinning during maturation and multiple psychiatric disorders suggests overlapping molecular underpinnings. This finding adds to the understanding of the neurodevelopmental mechanisms of psychiatric disorders.

Predictors of gaming disorder in children and adolescents: a school-based study

Objective:

To determine whether psychiatric and gaming pattern variables are associated with gaming disorder in a school-based sample.

Methods:

We analyzed data from the Brazilian High-Risk Cohort for Psychiatric Disorders, a community sample aged 10 to 18, using questionnaires on gaming use patterns. We applied the Gaming Addiction Scale to diagnose gaming disorder and the Development and Well-Being Behavior Assessment for other diagnoses.

Results:

Out of 407 subjects, 83 (20.4%) fulfilled the criteria for gaming disorder. More role-playing game players were diagnosed with gaming disorder that any other genre. Gaming disorder rates increased proportionally to the number of genres played. Playing online, being diagnosed with a mental disorder, and more hours of non-stop gaming were associated with higher rates of gaming disorder. When all variables (including age and gender) were considered in a logistic regression model, the number of genres played, the number of non-stop hours, the proportion of online games, and having a diagnosed mental disorder emerged as significant predictors of gaming disorder.

Conclusion:

Each variable seems to add further risk of gaming disorder among children and adolescents. Monitoring the length of gaming sessions, the number and type of genres played, time spent gaming online, and behavior changes may help parents or guardians identify unhealthy patterns of gaming behavior.

Relative Age and Attention-Deficit/Hyperactivity Disorder: Data From Three Epidemiological Cohorts and a Meta-analysis

OBJECTIVE

To investigate the effect of relatively younger age on attention-deficit/hyperactivity disorder (ADHD) symptoms and diagnosis through three population-based cohorts and a meta-analysis.

METHOD

This study included participants of three community-based cohorts in Brazil: 1993 Pelotas Cohort (N = 5,249), 2004 Pelotas Cohort (N = 4,231), and Brazilian High-Risk Study for Psychiatric Disorders (HRC study) (N = 2,511). We analyzed the effect of relatively younger age on ADHD symptoms and diagnosis. For the meta-analysis, we searched MEDLINE, PsycINFO, and Web of Science from inception through December 25, 2018. We selected studies that reported measures of association between relative immaturity and an ADHD diagnosis. We followed the Meta-analysis Of Observational Studies in Epidemiology guidelines. The protocol for meta-analysis is available on PROSPERO (CRD42018099966).

RESULTS

In the meta-analysis, we identified 1,799 potentially eligible records, from which 25 studies including 8,076,570 subjects (164,049 ADHD cases) were analyzed with their effect estimates. The summarized relative risk of an ADHD diagnosis was 1.34 (95% CI, 1.26-1.43, p < .001) for children born in the first 4 months of the school year (relatively younger). Heterogeneity was high (I² = 96.7%). Relative younger age was associated with higher levels of ADHD symptoms in the 1993 Pelotas Cohort (p = .003), 2004 Pelotas Cohort (p = .046), and HRC study (p = .010).

CONCLUSION

Children and adolescents who are relatively younger compared with their classmates have a higher risk of receiving an ADHD diagnosis. Clinicians should consider the developmental level of young children when evaluating ADHD symptoms.

Detecting multiple differentially methylated CpG sites and regions related to dimensional psychopathology in youths

Background

Psychiatric symptomatology during late childhood and early adolescence tends to persist later in life. In the present longitudinal study, we aimed to identify changes in genome-wide DNA methylation patterns that were associated with the emergence of psychopathology in youths from the Brazilian High-Risk Cohort (HRC) for psychiatric disorders. Moreover, for the differentially methylated genes, we verified whether differences in DNA methylation corresponded to differences in mRNA transcript levels by analyzing the gene expression levels in the blood and by correlating the variation of DNA methylation values with the variation of mRNA levels of the same individuals. Finally, we examined whether the variations in DNA methylation and mRNA levels were correlated with psychopathology measurements over time.

Methods

We selected 24 youths from the HRC who presented with an increase in dimensional psychopathology at a 3-year follow-up as measured by the Child Behavior Checklist (CBCL). The DNA methylation and gene expression data were compared in peripheral blood samples (n = 48) obtained from the 24 youths before and after developing psychopathology. We implemented a methodological framework to reduce the effect of chronological age on DNA methylation using an independent population of 140 youths and the effect of puberty using data from the literature.

Results

We identified 663 differentially methylated positions (DMPs) and 90 differentially methylated regions (DMRs) associated with the emergence of psychopathology. We observed that 15 DMPs were mapped to genes that were differentially expressed in the blood; among these, we found a correlation between the DNA methylation and mRNA levels of RB1CC1 and a correlation between the CBCL and mRNA levels of KMT2E. Of the DMRs, three genes were differentially expressed: ASCL2, which is involved in neurogenesis; HLA-E, which is mapped to the MHC loci; and RPS6KB1, the gene expression of which was correlated with an increase in the CBCL between the time points.

Conclusions

We observed that changes in DNA methylation and, consequently, in gene expression in the peripheral blood occurred concurrently with the emergence of dimensional psychopathology in youths. Therefore, epigenomic modulations might be involved in the regulation of an individual’s development of psychopathology.

Reaction time variability and attention-deficit/hyperactivity disorder: is increased reaction time variability specific to attention-deficit/hyperactivity disorder? Testing predictions from the default-mode interference hypothesis

Increased reaction time variability (RTV) is one of the most replicable behavioral correlates of attention-deficit/hyperactivity disorder (ADHD). However, this may not be specific to ADHD but a more general marker of psychopathology. Here we compare RT variability in individuals with ADHD and those with other childhood internalizing and externalizing conditions both in terms of standard (i.e., the standard deviation of reaction time) and alternative indices that capture low-frequency oscillatory patterns in RT variations over time thought to mark periodic lapses of attention in ADHD. A total of 667 participants (6-12 years old) were classified into non-overlapping diagnostic groups consisting of children with fear disorders (n = 91), distress disorders (n = 56), ADHD (n = 103), oppositional defiant or conduct disorder (ODD/CD; n = 40) and typically developing controls (TDC; n = 377). We used a simple two-choice reaction time task to measure reaction time. The strength of oscillations in RTs across the session was extracted using spectral analyses. Higher RTV was present in ADHD compared to all other disorder groups, effects that were equally strong across all frequency bands. Interestingly, we found that lower RTV to characterize ODD/CD relative to TDC, a finding that was more pronounced at lower frequencies. In general, our data support RTV as a specific marker of ADHD. RT variation across time in ADHD did not show periodicity in a specific frequency band, not supporting that ADHD RTV is the product of spontaneous periodic lapses of attention. Low-frequency oscillations may be particularly useful to differentiate ODD/CD from TDC.

Effects of the interaction between genetic factors and maltreatment on child and adolescent psychiatric disorders

We evaluated the effects of the interaction between child maltreatment (CM) and single nucleotide polymorphisms (SNPs) on development of mental disorders (MD) and psychopathology. We genotyped 720 individuals from a Brazilian community school-based prospective study, focusing on SNPs in 21 genes known to be associated with mental disorders. CM was assessed via a multi-informant-measure, which was previously validated. To test G × CM, we used linear or logistic models depending on variable evaluated (MD or dimensional psychopathology). After Bonferroni multiple comparison correction, we did not find any statistically significant association of G × CM with either MD or psychopathology.

Childhood trauma and adolescent psychotic experiences in a community-based cohort: The potential role of positive attributes as a protective factor

OBJECTIVE

To investigate how a set of positive social and personality characteristics called 'positive attributes' affects the emergence and persistence of Psychotic Experiences (PE) in adolescence.

METHOD

We used data from a community-based Brazilian High-Risk Cohort (HRC). 2511 6-12 year-old children were evaluated at baseline, and 80.05% completed a 3-year follow-up interview. At baseline, childhood trauma was assessed using parent- and self-report, and positive attributes were assessed by parent-report. Trained psychologists rated self-reported PE at both time points. Linear models evaluated the effect of childhood trauma and positive attributes on PE at follow-up. Mediation models tested i.) the indirect effect of positive attributes on the association between childhood trauma and follow-up PE and, ii.) the indirect effect of childhood trauma and positive attributes on the relationship between PE at baseline and follow-up.

RESULTS

Higher levels of baseline PE (B = 0.157, p < .001) and higher childhood trauma (B = 0.110, p < .001) were associated with increased follow-up PE. Higher positive attributes predicted lower PE after 3 years, adjusting for the prevalence of baseline PE and childhood trauma (B = -0.042, p < .022). Positive attributes partially mediated the relationship between childhood trauma and follow-up PE. The indirect pathway of childhood trauma and positive attributes mediated the association between baseline and follow-up PE.

CONCLUSIONS

Higher levels of positive social and behavioral traits in childhood may diminish the subsequent emergence of PE. As these attributes can be promoted, our findings suggest that positive attributes may represent a novel target for preventive interventions in children at risk of developing PE.

Effect of male-specific childhood trauma on telomere length

Child maltreatment (CM) is a global issue with serious lifelong consequences. In fact, maltreatment during childhood might be an important risk factor for the development of psychiatric disorders. Furthermore, previous studies showed a strong relationship between telomere length (TL) and early life stress. Considering that only a few studies have evaluated this relationship in children and that even fewer considered the sex as a possible moderator, we investigated whether TL in the blood of both children and adolescents was associated with psychopathology and with a history of CM, and whether these associations were moderated by the sex. In this cross-sectional study, 561 individuals (ranging between 6 and 14 years of age) from a large prospective community school-based study, i.e., the Brazilian High-Risk Cohort (HRC), were evaluated. The Child Behavior Checklist (CBCL) score was used to assess psychopathology, whereas a latent variable encompassing some questions about history of adverse environment and trauma was employed to determine the CM history. TL was measured in blood cells using a multiplex quantitative polymerase chain reaction. Additionally, TL was inserted in two moderation models, in which the CBCL score/CM, TL and sex were the independent variables, the outcome, and the moderator variable, respectively. Although an association between psychiatric symptoms and TL was not observed, a relation between CM and TL moderated by the sex was seen, indicating that males with higher CM scores presented with shorter telomeres than did females. Our results suggest that child maltreatment could influence telomere length in both children and adolescents and that this effect is mediated by the sex.

Reward Processing in Depression: A Conceptual and Meta-Analytic Review Across fMRI and EEG Studies

OBJECTIVE

A role for aberrant reward processing in the pathogenesis of depression has long been proposed. However, no review has yet examined its role in depression by integrating conceptual and quantitative findings across functional MRI (fMRI) and EEG methodologies. The authors quantified these effects, with an emphasis on development.

METHOD

A total of 38 fMRI and 12 EEG studies were entered into fMRI and EEG meta-analyses. fMRI studies primarily examined reward anticipation and reward feedback. These were analyzed using the activation likelihood estimation method. EEG studies involved mainly the feedback-related negativity (FRN) event-related potential, and these studies were analyzed using random-effects meta-analysis of the association between FRN and depression.

RESULTS

Analysis of fMRI studies revealed significantly reduced striatal activation in depressed compared with healthy individuals during reward feedback. When region-of-interest analyses were included, reduced activation was also observed in reward anticipation, an effect that was stronger in individuals under age 18. FRN was also significantly reduced in depression, with pronounced effects in individuals under age 18. In longitudinal studies, reduced striatal activation in fMRI and blunted FRN in EEG were found to precede the onset of depression in adolescents.

CONCLUSIONS

Taken together, the findings show consistent neural aberrations during reward processing in depression, namely, reduced striatal signal during feedback and blunted FRN. These aberrations may underlie the pathogenesis of depression and have important implications for development of new treatments.

Polygenic Risk Score for Alzheimer's Disease: Implications for Memory Performance and Hippocampal Volumes in Early Life

OBJECTIVE

Alzheimer's disease is a heritable neurodegenerative disorder in which early-life precursors may manifest in cognition and brain structure. The authors evaluate this possibility by examining, in youths, associations among polygenic risk score for Alzheimer's disease, cognitive abilities, and hippocampal volume.

METHOD

Participants were children 6-14 years of age in two Brazilian cities, constituting the discovery (N=364) and replication samples (N=352). As an additional replication, data from a Canadian sample (N=1,029), with distinct tasks, MRI protocol, and genetic risk, were included. Cognitive tests quantified memory and executive function. Reading and writing abilities were assessed by standardized tests. Hippocampal volumes were derived from the Multiple Automatically Generated Templates (MAGeT) multi-atlas segmentation brain algorithm. Genetic risk for Alzheimer's disease was quantified using summary statistics from the International Genomics of Alzheimer's Project.

RESULTS

Analyses showed that for the Brazilian discovery sample, each one-unit increase in z-score for Alzheimer's polygenic risk score significantly predicted a 0.185 decrement in z-score for immediate recall and a 0.282 decrement for delayed recall. Findings were similar for the Brazilian replication sample (immediate and delayed recall, β=-0.259 and β=-0.232, both significant). Quantile regressions showed lower hippocampal volumes bilaterally for individuals with high polygenic risk scores. Associations fell short of significance for the Canadian sample.

CONCLUSIONS

Genetic risk for Alzheimer's disease may affect early-life cognition and hippocampal volumes, as shown in two independent samples. These data support previous evidence that some forms of late-life dementia may represent developmental conditions with roots in childhood. This result may vary depending on a sample's genetic risk and may be specific to some types of memory tasks.

Testing Measurement Invariance across Groups of Children with and without Attention-Deficit/ Hyperactivity Disorder: Applications for Word Recognition and Spelling Tasks

Although studies have consistently demonstrated that children with attention-deficit/hyperactivity disorder (ADHD) perform significantly lower than controls on word recognition and spelling tests, such studies rely on the assumption that those groups are comparable in these measures. This study investigates comparability of word recognition and spelling tests based on diagnostic status for ADHD through measurement invariance methods. The participants (n = 1,935; 47% female; 11% ADHD) were children aged 6–15 with normal IQ (≥70). Measurement invariance was investigated through Confirmatory Factor Analysis and Multiple Indicators Multiple Causes models. Measurement invariance was attested in both methods, demonstrating the direct comparability of the groups. Children with ADHD were 0.51 SD lower in word recognition and 0.33 SD lower in spelling tests than controls. Results suggest that differences in performance on word recognition and spelling tests are related to true mean differences based on ADHD diagnostic status. Implications for clinical practice and research are discussed.

Prevalence, clinical correlates and maternal psychopathology of deliberate self-harm in children and early adolescents: results from a large community study

Objectives:

Little is known about the prevalence and correlates of deliberate self-harm (DSH) in children from low- and middle-income countries. We investigated the prevalence of DSH and its clinical and maternal psychopathological associations in Brazilian children (n=2,508, ages 6-14y) in a community-based study.

Methods:

Participants of the High Risk Cohort Study for the Development of Childhood Psychiatric Disorders (HRC) and their mothers were assessed in structured interviews. Current (last month) and lifetime DSH were estimated, including analysis stratified by age groups. Logistic regressions were performed to investigate the role of the children’s clinical diagnoses and maternal psychopathology on DSH prevalence estimates, adjusting for potential confounding factors.

Results:

The prevalence of current DSH was 0.8% (children 0.6%, adolescents 1%) and lifetime DSH was 1.6% (1.8% and 1.5%, respectively). Current and lifetime DSH were more frequent in children with depression, attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD), even in multiple models accounting for demographic variables and co-occurring psychiatric disorders. Maternal anxiety disorder was strongly associated with current and lifetime DSH in offspring; whereas current DSH, specifically in young children, was associated with maternal mood disorder.

Conclusion:

Diagnoses of depression, ADHD and ODD were consistently associated with DSH, as was having a mother with anxiety disorder.

Perinatal complications, lipid peroxidation, and mental health problems in a large community pediatric sample

Replicated evidence indicates that perinatal complications are associated with increased markers of oxidative stress and with mental health problems in children. However, there are fewer reports on the impact of perinatal complications in later phases of development. We aimed to investigate the estimated effects of perinatal complications on levels of lipid peroxidation and on psychopathology in children and adolescents. The study is part of the High Risk Cohort Study for Psychiatric Disorders; the population was composed by 554 students, 6-14 years of age. Serum levels of malondialdehyde, a product of lipid peroxidation, were measured by the TBARS method. A household interview with parents and caregivers was conducted and included inquiries about perinatal history, the Child Behavior Checklist (CBCL), and parent's evaluation, using the Mini International Psychiatric Interview (MINI). We created a cumulative risk index, conceptualized as each individual's cumulative exposure to perinatal complications. Results indicate that perinatal complications were associated with higher levels of TBARS. After adjusting for age, gender, socio-economic status, CBCL total problems score, parental psychopathology, and childhood maltreatment, children exposed to 3 or more perinatal complications had an 26.9% (95% CI 9.9%, 46.6%) increase in TBARS levels, relative to the unexposed group. Exploratory mediation analysis indicated that TBARS levels partially mediated the association between perinatal complications and externalizing problems. In conclusion, an adverse intrauterine and/or early life environment, as proxied by the cumulative exposure to perinatal complications, was independently associated with higher levels of lipid peroxidation in children and adolescents.

Association between irritability and bias in attention orienting to threat in children and adolescents

BACKGROUND

Irritability, a frequent complaint in children with psychiatric disorders, reflects increased predisposition to anger. Preliminary work in pediatric clinical samples links irritability to attention bias to threat, and the current study examines this association in a large population-based sample.

METHODS

We studied 1,872 children (ages 6-14) using the Development and Well-Being Assessment (DAWBA), Childhood Behavior Checklist (CBCL), and dot-probe tasks. Irritability was defined using CBCL items that assessed temper tantrums and hot temper. The dot-probe task assessed attention biases for threat-related (angry face) stimuli. Multiple regression analysis was used to assess specificity of associations to irritability when adjusting for demographic variables and co-occurring psychiatric traits. Propensity score matching analysis was used to increase causal inference when matching for demographic variables and co-occurring psychiatric traits.

RESULTS

Irritability was associated with increased attention bias toward threat-related cues. Multiple regression analysis suggests associations between irritability and threat bias are independent from demographic variables, anxiety, and externalizing traits (attention-deficit/hyperactivity, conduct, and headstrong/hurtful), but not from broad internalizing symptoms. Propensity score matching analysis indicated that this association was found for irritable versus nonirritable groups matched on demographic and co-occurring traits including internalizing symptoms.

CONCLUSIONS

Irritability in children is associated with biased attention toward threatening information. This finding, if replicated, warrants further investigation to examine the extent to which it contributes to chronic irritability and to explore possible treatment implications.

Specific and social fears in children and adolescents: separating normative fears from problem indicators and phobias

Objective:

To distinguish normative fears from problematic fears and phobias.

Methods:

We investigated 2,512 children and adolescents from a large community school-based study, the High Risk Study for Psychiatric Disorders. Parent reports of 18 fears and psychiatric diagnosis were investigated. We used two analytical approaches: confirmatory factor analysis (CFA)/item response theory (IRT) and nonparametric receiver operating characteristic (ROC) curve.

Results:

According to IRT and ROC analyses, social fears are more likely to indicate problems and phobias than specific fears. Most specific fears were normative when mild; all specific fears indicate problems when pervasive. In addition, the situational fear of toilets and people who look unusual were highly indicative of specific phobia. Among social fears, those not restricted to performance and fear of writing in front of others indicate problems when mild. All social fears indicate problems and are highly indicative of social phobia when pervasive.

Conclusion:

These preliminary findings provide guidance for clinicians and researchers to determine the boundaries that separate normative fears from problem indicators in children and adolescents, and indicate a differential severity threshold for specific and social fears.

Poor stimulus discriminability as a common neuropsychological deficit between ADHD and reading ability in young children: a moderated mediation model

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is frequently associated with poorer reading ability; however, the specific neuropsychological domains linking this co-occurrence remain unclear. This study evaluates information-processing characteristics as possible neuropsychological links between ADHD symptoms and RA in a community-based sample of children and early adolescents with normal IQ (⩾70).

METHOD

The participants (n = 1857, aged 6-15 years, 47% female) were evaluated for reading ability (reading single words aloud) and information processing [stimulus discriminability in the two-choice reaction-time task estimated using diffusion models]. ADHD symptoms were ascertained through informant (parent) report using the Development and Well-Being Assessment (DAWBA). Verbal working memory (VWM; digit span backwards), visuospatial working memory (VSWM, Corsi Blocks backwards), sex, socioeconomic status, and IQ were included as covariates.

RESULTS

In a moderated mediation model, stimulus discriminability mediated the effect of ADHD on reading ability. This indirect effect was moderated by age such that a larger effect was seen among younger children.

CONCLUSION

The findings support the hypothesis that ADHD and reading ability are linked among young children via a neuropsychological deficit related to stimulus discriminability. Early interventions targeting stimulus discriminability might improve symptoms of inattention/hyperactivity and reading ability.

A general psychopathology factor (P factor) in children: Structural model analysis and external validation through familial risk and child global executive function

High rates of comorbidities and poor validity of disorder diagnostic criteria for mental disorders hamper advances in mental health research. Recent work has suggested the utility of continuous cross-cutting dimensions, including general psychopathology and specific factors of externalizing and internalizing (e.g., distress and fear) syndromes. The current study evaluated the reliability of competing structural models of psychopathology and examined external validity of the best fitting model on the basis of family risk and child global executive function (EF). A community sample of 8,012 families from Brazil with children ages 6-12 years completed structured interviews about the child and parental psychiatric syndromes, and a subsample of 2,395 children completed tasks assessing EF (i.e., working memory, inhibitory control, and time processing). Confirmatory factor analyses tested a series of structural models of psychopathology in both parents and children. The model with a general psychopathology factor ("P factor") with 3 specific factors (fear, distress, and externalizing) exhibited the best fit. The general P factor accounted for most of the variance in all models, with little residual variance explained by each of the 3 specific factors. In addition, associations between child and parental factors were mainly significant for the P factors and nonsignificant for the specific factors from the respective models. Likewise, the child P factor-but not the specific factors-was significantly associated with global child EF. Overall, our results provide support for a latent overarching P factor characterizing child psychopathology, supported by familial associations and child EF. (PsycINFO Database Record

Serum copeptin in children exposed to maltreatment

AIM

Childhood maltreatment (CM) has been related to a persistent reprograming of stress-response. Copeptin is a marker of hypothalamic-pituitary-adrenal axis activation; however, few studies have examined copeptin levels in children exposed to CM. The aim of this study was to compare serum copeptin levels in children reporting child abuse and/or neglect and children with no history of CM.

METHODS

This study included 65 children with a positive history of moderate to severe CM, as reported by themselves and their parent(s) during a clinical interview, and 71 children with no history of CM as a comparison group. CM was considered moderate to severe based on the child-reported frequency of being exposed to events related to sexual abuse, physical abuse, emotional abuse, emotional neglect, and/or physical neglect. Child psychopathology symptoms were assessed using the Child Behavior Checklist (CBCL). We measured serum copeptin concentration using enzyme-linked immunosorbent assay.

RESULTS

Children exposed to CM exhibited higher levels of serum copeptin compared to children without CM when controlling for sex, age, and psychiatric morbidity. The CBCL total score, including internalizing and externalizing symptoms, was higher in children with CM. We found no correlation between copeptin and CBCL scores for internalizing symptoms and externalizing symptoms.

CONCLUSION

CM is associated with copeptin serum levels independently of age, sex, and symptom severity. Copeptin is a promising new biomarker for children with a history of abuse and/or neglect.

Association of serum interleukin-6 with mental health problems in children exposed to perinatal complications and social disadvantage

There is consistent evidence that inflammation is involved in mental disorders pathogenesis. Herein, using data from the High Risk Cohort Study for Psychiatric Disorders, we investigated the relationship between parental mood disorders (PMD), environmental factors, serum interleukin-6 (IL6) and mental health problems in children aged 6-12. We measured the serum levels of IL6 in 567 children. Information related to socio-demographic characteristics, mental health problems and multiple risk factors, as well as parent's psychiatric diagnosis, was captured. We evaluated two groups of environmental risk factors (i.e. perinatal complications and social disadvantage) using a cumulative risk model. Results showed that higher serum levels of IL6 were associated with PMD (RR=1.072, p=0.001), perinatal complications (RR=1.022, p=0.013) and social disadvantage (RR=1.024, p=0.021). There was an interaction between PMD and social disadvantage (RR=1.141, p=0.021), as the effect of PMD on IL6 was significantly higher in children exposed to higher levels of social disadvantage. Moreover, there was a positive correlation between IL6 and mental health problems (RR=1.099, p=0.026), which was moderated by exposure to perinatal complications or social disadvantage (RR=1.273, p=0.015 and RR=1.179, p=0.048, respectively). In conclusions, there is evidence of a differential inflammatory activation in children with PMD and exposure to environmental risk factors, when compared to matched peers. Systemic inflammation may be involved in the pathway linking familial risk and mental health problems.

Socioeconomic Disadvantage Moderates the Association between Peripheral Biomarkers and Childhood Psychopathology

BACKGROUND

Socioeconomic disadvantage (SED) has been consistently associated with early life mental health problems. SED has been shown to impact multiple biological systems, including the regulation of neurotrophic proteins, immune-inflammatory and oxidative stress markers, which, conversely, have been reported to be relevant to physiological and pathological neurodevelopment This study investigated the relationship between SED, different domains of psychopathology, serum levels of interleukin-6 (IL6), thiobarbituric acid-reactive substance (TBARS) and brain-derived neurotrophic factor (BDNF). We hypothesized that a composite of socioeconomic risk would be associated with psychopathology and altered levels of peripheral biomarkers. In addition, we hypothesized that SED would moderate the associations between mental health problems, IL6, TBARS and BDNF.

METHODS AND FINDINGS

Using a cross-sectional design, we measured the serum levels of IL6, TBARS and BDNF in 495 children aged 6 to 12. We also investigated socio-demographic characteristics and mental health problems using the Child Behaviour Checklist (CBCL) DSM-oriented scales. SED was evaluated using a cumulative risk model. Generalized linear models were used to assess associations between SED, biomarkers levels and psychopathology. SED was significantly associated with serum levels of IL6 (RR = 1.026, 95% CI 1.004; 1.049, p = 0.020) and TBARS (RR = 1.077, 95% CI 1.028; 1.127, p = 0.002). The association between SED and BDNF was not statistically significant (RR = 1.031, 95% CI 0.997; 1.066, p = 0.077). SED was also significantly associated with all CBCL DSM-oriented scales (all p < 0.05), whereas serum biomarkers (i.e. IL6, TBARS, BDNF) were associated with specific subscales. Moreover, the associations between serum biomarkers and domains of psychopathology were moderated by SED, with stronger correlations between mental health problems, IL6, TBARS, and BDNF being observed in children with high SED.

CONCLUSIONS

In children, SED is highly associated with mental health problems. Our findings suggest that this association may be moderated via effects on multiple interacting neurobiological systems.

Inflammation, neurotrophism and oxidative stress and childhood psychopathology in a large community sample

OBJECTIVE

To investigate the association between peripheral biomarkers and child psychopathology in a large community sample.

METHOD

A total of 625 aged 6- to 13-year old subjects were recruited from a community school-based study. Psychopathology was assessed using the Child Behaviour Checklist (CBCL). Psychiatric diagnosis was evaluated using the Development and Well-Being Assessment. The following biomarkers were examined in peripheral blood: brain-derived neurotrophic factor, cytokines (IL-2, IL-4, IL-6, IL-10, IL-17, IFN-g, and TNF-α), chemokines (eotaxin/CCL11, IP-10, MCP-1), cytokine receptors (sTNFR1 and sTNFR2), and the oxidative stress marker TBARS.

RESULTS

We found significant associations between sTNFR2, eotaxin/CCL11 and CBCL total score, as well as with specific dimensions of psychopathology. There were different patterns of association between these biomarkers and psychological and behavioural symptoms in children with and without a mental disorder. TBARS, IL-6 and MCP-1 were more specific to some clusters of symptoms in children with a psychiatric diagnosis.

CONCLUSION

Our data support the potential use of biomarkers, especially those involved in immune-inflammatory pathways, in investigating neurodevelopmental psychopathology. Their association with different dimensions of symptoms might be of useful when analyzing illness severity and clusters of symptoms within specific disorders.

Abnormalities in sleep patterns in individuals at risk for psychosis and bipolar disorder

AIM

To compare patterns of sleep and the presence of sleep disturbances in individuals in at-risk mental states (ARMS) for psychosis and bipolar disorder (BD) with a healthy control (HC) group.

METHODS

This was a comparative study involving 20 individuals in ARMS for psychosis or BD, according to the Comprehensive Assessment of At-Risk Mental States, and 20 age- and sex-matched healthy controls. Quality of sleep in the previous month was assessed using the Pittsburgh Sleep Quality Index, diurnal somnolence was evaluated using The Epworth Sleepiness Scale, and chronotype was determined using the Questionnaire of Morningness/Eveningness (QME). All of the participants underwent polysomnography (PSG) during the entire night for two consecutive nights. The first night aimed to adapt the subject to the environment, and only the data from the second night were used for the analysis.

RESULTS

Compared with the HC group, individuals in the ARMS group reported significantly worse sleep quality, as measured by the Pittsburgh Sleep Quality Index. Both groups had scores consistent with daytime sleepiness on the Epworth Sleepiness Scale, and there were no differences with regard to chronotype between the groups, with a predominance of the indifferent type in both groups. In the PSG assessment, we observed increased Sleep Latency (SL) and increased Rapid Eye Movement Sleep Onset Latency (REMOL) in the ARMS group, compared to the HC group.

CONCLUSION

The results of this study indicated that sleep abnormalities could be found early in the course of mental diseases, even in at-risk stages, and support the further investigation of their predictive value in the transition to psychosis and BD.

Gene expression analysis in blood of ultra-high risk subjects compared to first-episode of psychosis patients and controls

OBJECTIVES

This study aimed to investigate peripheral blood gene expression in ultra-high-risk subjects (UHR) compared to first-episode psychosis individuals (FEP) and healthy controls (HC).

METHODS

We enrolled 22 UHR, 66 FEP and 67 HC and investigated the expression of 12 genes using Taqman assays. We used the Univariate General Linear Model, as well as Bonferroni correction for multiple comparisons.

RESULTS

We found that UFD1L (ubiquitin fusion degradation 1 like (yeast)) gene was upregulated in UHR group compared to HC and FEP (P = 3.44 × 10^-6 ; P = 9.41 × 10^-6). MBP (myelin basic protein) was downregulated in UHR compared to FEP (P = 6.07 × 10^-6). DISC1 (disrupted in schizophrenia 1) was also upregulated in UHR compared to FEP but lost statistical significance when corrected for age.

CONCLUSIONS

These genes are directly related to neurodevelopmental processes and have been associated to schizophrenia. Recent findings described that DISC1 overexpression can disrupt MBP expression, thus, we think that these alterations in UHR individuals could be associated with a common process. UFD1L showed a different pattern of expression only for UHR group, suggesting that they can be under an acute endoplasmatic reticulum stress, demanding elevated levels of Ufd1. Further studies can improve knowledge on disease progression and putative targets to preventive strategies.

Specificity of basic information processing and inhibitory control in attention deficit hyperactivity disorder

BACKGROUND

Both inhibitory-based executive functioning (IB-EF) and basic information processing (BIP) deficits are found in clinic-referred attention deficit hyperactivity disorder (ADHD) samples. However, it remains to be determined whether: (1) such deficits occur in non-referred samples of ADHD; (2) they are specific to ADHD; (3) the co-morbidity between ADHD and oppositional defiant disorder/conduct disorder (ODD/CD) has additive or interactive effects; and (4) IB-EF deficits are primary in ADHD or are due to BIP deficits.

METHOD

We assessed 704 subjects (age 6-12 years) from a non-referred sample using the Development and Well-Being Assessment (DAWBA) and classified them into five groups: typical developing controls (TDC; n = 378), Fear disorders (n = 90), Distress disorders (n = 57), ADHD (n = 100), ODD/CD (n = 40) and ADHD+ODD/CD (n = 39). We evaluated neurocognitive performance with a Two-Choice Reaction Time Task (2C-RT), a Conflict Control Task (CCT) and a Go/No-Go (GNG) task. We used a diffusion model (DM) to decompose BIP into processing efficiency, speed-accuracy trade-off and encoding/motor function along with variability parameters.

RESULTS

Poorer processing efficiency was found to be specific to ADHD. Faster encoding/motor function differentiated ADHD from TDC and from fear/distress whereas a more cautious (not impulsive) response style differentiated ADHD from both TDC and ODD/CD. The co-morbidity between ADHD and ODD/CD reflected only additive effects. All ADHD-related IB-EF classical effects were fully moderated by deficits in BIP.

CONCLUSIONS

Our findings challenge the IB-EF hypothesis for ADHD and underscore the importance of processing efficiency as the key specific mechanism for ADHD pathophysiology.

Cutting edge: evidence for a signaling partnership between urokinase receptors (CD87) and L-selectin (CD62L) in human polymorphonuclear neutrophils

Leukocyte urokinase plasminogen activator receptors (uPARs) cluster at adhesion interfaces and at migratory fronts where they participate in adhesion, chemotaxis, and proteolysis. uPAR aggregation triggers activation signaling even though this glycolipid-anchored protein must associate with membrane-spanning proteins to access the cell interior. This study demonstrates a novel partnership between uPAR and L-selectin in human polymorphonuclear neutrophils. Fluorescence resonance energy transfer demonstrated a direct physical association between uPAR and L-selectin. To examine the role of L-selectin in uPAR-mediated signaling, uPAR was cross-linked and intracellular Ca(2+) concentrations were measured by spectrofluorometry. A mAb reactive against the carbohydrate binding domain (CBD) of L-selectin substantially inhibited uPAR-mediated Ca(2+) mobilization, whereas mAbs against the beta(2) integrin complement receptor 3 (CR3), another uPAR-binding adhesion protein, had no effect. Similarly, fucoidan, a sulfated polysaccharide that binds to L-selectin CBD, inhibited the Ca(2+) signal. We conclude that uPAR associates with the CBD region of L-selectin to form a functional signaling complex.

Clustering of urokinase receptors (uPAR; CD87) induces proinflammatory signaling in human polymorphonuclear neutrophils

Leukocytes use urokinase receptors (uPAR; CD87) in adhesion, migration, and proteolysis of matrix proteins. Typically, uPAR clusters at cell-substratum interfaces, at focal adhesions, and at the leading edges of migrating cells. This study was undertaken to determine whether uPAR clustering mediates activation signaling in human polymorphonuclear neutrophils. Cells were labeled with fluo-3/AM to quantitate intracellular Ca2+ ([Ca2+]i) by spectrofluorometry, and uPAR was aggregated by Ab cross-linking. Aggregating uPAR induced a highly reproducible increase in [Ca2+]i (baseline to peak) of 295 +/- 37 nM (p = 0.0002). Acutely treating cells with high m.w. urokinase (HMW-uPA; 4000 IU/ml) produced a response of similar magnitude but far shorter duration. Selectively aggregating uPA-occupied uPAR produced smaller increases in [Ca2+]i, but saturating uPAR with HMW-uPA increased the response to approximate that of uPAR cross-linking. Cross-linking uPAR induced rapid and significant increases in membrane expression of CD11b and increased degranulation (release of beta-glucuronidase and lactoferrin) to a significantly greater degree than cross-linking control Abs. The magnitude of degranulation correlated closely with the difference between baseline and peak [Ca2+]i, but was not dependent on the state of uPA occupancy. By contrast, selectively cross-linking uPA-occupied uPAR was capable of directly inducing superoxide release as well as enhancing FMLP-stimulated superoxide release. These results could not be duplicated by preferentially cross-linking unoccupied uPAR. We conclude that uPAR aggregation initiates activation signaling in polymorphonuclear neutrophils through at least two distinct uPA-dependent and uPA-independent pathways, increasing their proinflammatory potency (degranulation and oxidant release) and altering expression of CD11b/CD18 to favor a firmly adherent phenotype.

Urokinase receptor (CD87) aggregation triggers phosphoinositide hydrolysis and intracellular calcium mobilization in mononuclear phagocytes

Leukocytes utilize urokinase receptors (uPAR; CD87) in adhesion, migration, and matrix proteolysis. uPAR aggregate at cell-substratum interfaces and at leading edges of migrating cells, so this study was undertaken to determine whether uPAR aggregation is capable of initiating activation signaling. Monocyte-like U937 cells were labeled with fluo-3-acetoxymethyl ester to quantitate intracellular Ca2+ concentrations ([Ca2+]i) by spectrofluorometry, and uPAR was aggregated by mAb cross-linking. uPAR aggregation induced highly reproducible increases in [Ca2+]i of 103.0 +/- 10.9 nM (p < 0.0001) and >3-fold increases in cellular d-myoinositol 1,4,5-trisphosphate (Ins(1,4,5)P3) levels. Similar increases in [Ca2+]i were also elicited by uPAR aggregation in human monocytes, but cross-linking a control IgG2a had no effect on [Ca2+]i. Selectively cross-linking uPA-occupied uPAR with an anti-uPA mAb produced smaller increases in [Ca2+]i, but fully saturating uPAR with exogenous uPA enhanced the [Ca2+]i response to equal the effect of aggregating uPAR directly. Increased [Ca2+]i was inhibited by thapsigargin, herbimycin A, and U73122, but only partially reduced by low extracellular [Ca2+], indicating that uPAR aggregation increases [Ca2+]i by activating phospholipase C through a tyrosine kinase-dependent mechanism, generating Ins(1,4,5)P3 and releasing Ca2+ from Ins(1,4, 5)P3-sensitive intracellular stores. Cross-linking the beta2 integrin CR3 could not duplicate the effect of uPAR cross-linking, and uPAR-triggered Ca2+ mobilization was not blocked by anti-CR3 mAbs. These results indicate that uPAR aggregation initiates phosphoinositide hydrolysis by mechanisms that are not strictly dependent on associated uPA or CR3.

Fibrinogen activates NF-kappa B transcription factors in mononuclear phagocytes

Adhesion to extracellular matrices is known to modulate leukocyte activation, although the mechanisms are not fully understood. Mononuclear phagocytes are exposed to fibrinous provisional matrix throughout migration into inflammatory foci, so this study was undertaken to determine whether fibrinogen triggers activation of NF-kappa B transcription factors. U937 cells differentiated with PMA in nonadherent culture were shown to express two fibrinogen-binding integrins, predominately CD11b/CD18, and to a lesser extent, CD11c/CD18. Cells stimulated with fibrinogen (10-100 microg/ml)/Mn2+ (50 microM) for 2 h were examined by electrophoretic mobility shift assay. NF-kappa B activation, minimal in unstimulated cells, was substantially up-regulated by fibrinogen. Fibrinogen also caused activation of AP-1, but not SP1 or cAMP response element-binding protein (CREB) factors. Blocking mAbs against CD18 and CD11b abrogated fibrinogen-induced NF-kappa B activation. To determine the effects on transcriptional regulation, U937 cells were transfected with a plasmid containing the HIV-1 enhancer (bearing two NF-kappa B sites) coupled to a chloramphenicol acetyltransferase (CAT) reporter. Cells were subsequently stimulated with 1) PMA for 24 h, inducing CAT activity by 2.6-fold, 2) fibrinogen/Mn2+ for 2 h, inducing CAT activity by 3.2-fold, or 3) costimulation with fibrinogen and PMA, inducing 5.7-fold the CAT activity induced by PMA alone. We conclude that contact with fibrinogen-derived proteins may contribute to mononuclear phagocyte activation by signaling through CD11b/CD18, resulting in selective activation of transcriptional regulatory factors, including NF-kappa B.

Enhancement of analgesic effect of intrathecal neostigmine and clonidine on bupivacaine spinal anesthesia

BACKGROUND AND OBJECTIVES

Intrathecal administration of neostigmine has been shown to produce analgesia in both animals and humans. The concurrent administration of intrathecal neostigmine and clonidine has been reported to produce no neurotoxicity in sheep. The purpose of the present study was to evaluate the efficacy and safety of the combining intrathecal neostigmine and clonidine for the relief of pain in patients after cesarean delivery.

METHODS

After giving their consents, 80 parturients who were scheduled for cesarean delivery during spinal anesthesia were enrolled by a double-blind randomized design into four groups: bupivacaine group (n = 20) received intrathecal (i.t.) 10 mg bupivacaine; bupivacaine + neostigmine group (n = 19) received i.t. 10 mg bupivacaine + 50 microg neostigmine; bupivacaine + clonidine group (n = 20) received i.t. 10 mg bupivacaine + 150 microg clonidine; and bupivacaine + both (n = 21) received i.t. 10 mg bupivacaine + 50 microg neostigmine + 150 microg clonidine. The maximum spread of anesthesia, duration of analgesia and motor block, vital signs, and incidence of adverse effects were recorded for 14 hours postinjection. Fifty milligrams intramuscular meperidine was given as a rescue analgesic whenever patient's pain score was greater than 5/10 by the visual analog scale.

RESULTS

The demographic data were similar for all four groups. Bupivacaine + both group had a significantly higher maximum spread of anesthesia of 23.3 +/- 2.9 segments than bupivacaine group of 20.5 +/- 2.9 segment. Bupivacaine + both group showed a later onset of postsurgical pain of 6.5 +/- 1.5 hours as compared to bupivacaine group of 1.3 +/- 0.6 hours. The pain score in bupivacaine + both group was significantly lower than that of bupivacaine group during the first 10 hours. The 24-hour meperidine consumption also was lower in bupivacaine + both group than that of bupivacaine group. However, motor block was significantly prolonged from 3.5 +/- 1.1 hours in bupivacaine group to 7.1 +/- 1.6 hours in bupivacaine + both group. In addition, other side effects such as nausea and vomiting and dizziness were significantly increased in bupivacaine + both group.

CONCLUSION

Our study showed that the combination of 150 microg i.t. clonidine and 50 microg neostigmine provided longer postsurgical analgesia than with either drug used alone. However, this combination also produced significantly more adverse effects of prolonged motor block and nausea and vomiting. A further study combining the two study drugs but using a lower dose of i.t. neostigmine (e.g., 25 microg) is recommended.