The results leading to this publication have received funding from the Innovative Medicines Initiative 2 Joint Undertaking under grant agreement No 777394 for the project AIMS-2-TRIALS. This Joint Undertaking receives support from the European Union's Horizon 2020 research and innovation programme and EFPIA and AUTISM SPEAKS, Autistica, SFARI. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results. Any views expressed are those of the author(s) and not necessarily those of the funders.
In recent years, there has been a surge of interest in the general factor of psychopathology ("p"), which is intended to summarize broad psychiatric comorbidity into a single index. In this study, rather than attempting to validate this model using statistical techniques, we compared the magnitude (as indicated by the variance explained in the respective indicators) and the predictive validity of the "p" factor with those of the general factor of intelligence ("g"). To compare the magnitude, for "g", we analyzed fifteen Wechsler Adult Intelligence Scale subtests (N=1,200). For "p", we analyzed fourteen psychiatric diagnoses in Swedish adults (N=909,699), eight self‐ and parent‐rated psychopathology scales in Swedish adolescents (N=2,069), and sixteen parent‐rated psychopathology scales in Swedish children (N=14,589). To compare the predictive validity, we analyzed Swedish male military conscripts (N=414,595, mean age: 18.3 years) with measures on both "g" and "p" (derived from eight psychiatric diagnoses). We then examined their unique associations with three intelligence‐related outcomes (annual income, highest education, and university entrance exam scores), and sixteen adverse outcomes (e.g., suicidal behavior, psychotropic medication prescription, and criminality) retrieved from registers (mean age at follow‐up = 29.2 years). Results indicated that the magnitudes of "g" and "p" were very similar. Controlling for "p", "g" significantly predicted later education (standardized beta, β=0.38, SE=0.01) and university entrance exam scores (β=0.48, SE=0.01). Controlling for "g", "p" significantly predicted all adverse outcomes (mean β=0.32; range: 0.15 to 0.47). These findings support the notion that psychopathology indicators can be combined into a single score, similar to how intelligence subtests are combined into a general intelligence score. This "p" score might supplement specific diagnoses when formulating a management plan and predicting prognosis.
The objective of this pilot study was to evaluate the effectiveness of a group-based intervention aiming at improving social and communication skills in individuals with autism spectrum disorder. Over a period of 11 months, N = 17 children and adolescents received treatment according to the manualised Frankfurt Social Skills Training (KONTAKT). Parent, teacher, expert and blind expert ratings were assessed to judge outcome regarding peer interaction, autistic behaviours, adaptive functioning and family burden. The participants exhibited improvements pre to follow-up treatment, particularly in the area of autistic symptomatology. Effect sizes (partial eta squared) ranged from 0.02 to 0.69. Among other things, regression models showed a positive influence of IQ and language skills on gains in social skills. Findings indicate that KONTAKT might be useful for enhancing social skills and reducing autism-related psychopathology over time in different contexts. Nevertheless, controlled trials are needed to reassure its effectiveness.
In: Twin research and human genetics: the official journal of the International Society for Twin Studies (ISTS) and the Human Genetics Society of Australasia, Band 17, Heft 6, S. 553-562
Background: Recent studies have reported associations between air pollution exposure and neurodevelopmental disorders in children, but the role of pre- and postnatal exposure has not been elucidated. Aim: We aimed to explore the risk for autism spectrum disorders (ASD) and attention-deficit hyperactivity disorder (ADHD) among children in relation to pre- and postnatal exposure to air pollution from road traffic. Methods: Parents of 3,426 twins born in Stockholm during 1992–2000 were interviewed, when their children were 9 or 12 years old, for symptoms of neurodevelopmental disorders. Residence time-weighted concentrations of particulate matter with a diameter <10 μm (PM10) and nitrogen oxides (NOx) from road traffic were estimated at participants' addresses during pregnancy, the first year, and the ninth year of life using dispersion modeling, controlling for seasonal variation. Multivariate regression models were used to examine the association between air pollution exposure and neurodevelopmental outcomes, adjusting for potential confounding factors. Results: No clear or consistent associations were found between air pollution exposure during any of the three time windows and any of the neurodevelopmental outcomes. For example, a 5–95% difference in exposure to NOx during pregnancy was associated with odds ratios (ORs) of 0.92 (95% confidence interval (CI): 0.44–1.96) and 0.90 (95% CI: 0.58–1.40) for ASD and ADHD respectively. A corresponding range in exposure to PM10 during pregnancy was related to ORs of 1.01 (95% CI: 0.52–1.96) and 1.00 (95% CI: 0.68–1.47) for ASD and ADHD. Conclusions: Our data do not provide support for an association between pre- or postnatal exposure to air pollution from road traffic and neurodevelopmental disorders in children.
The results leading to this publication have received funding from the Innovative Medicines Initiative 2 Joint Undertaking under grant agreement No 777394 for the project AIMS-2-TRIALS. This Joint Undertaking receives support from the European Union's Horizon 2020 research and innovation programme and EFPIA and AUTISM SPEAKS, Autistica, SFARI. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results. Any views expressed are those of the author(s) and not necessarily those of the funders.
In: Twin research and human genetics: the official journal of the International Society for Twin Studies (ISTS) and the Human Genetics Society of Australasia, Band 21, Heft 1, S. 1-11
Hundreds of penetrant risk loci have been identified across different neurodevelopmental disorders (NDDs), and these often involve rare (<1% frequency) copy number variations (CNVs), which can involve one or more genes. Monozygotic (MZ) twin pairs are long thought to share 100% of their genomic information. However, genetic differences in the form of postzygotic somatic variants have been reported recently both in typically developing (TD) and in clinically discordant MZ pairs. We sought to investigate the contribution of rare CNVs in 100 twin pairs enriched for NDD phenotypes with a particular focus on postzygotic CNVs in MZ pairs discordant for autism spectrum disorder (ASD) using the Illumina Infinium PsychArray. In our sample, no postzygotic de novo CNVs were found in 55 MZ twin pairs, including the 13 pairs discordant for ASD. We did detect a higher rate of CNVs overlapping genes involved in disorders of the nervous system, such as a rare deletion affecting HNRNPU, in MZ pairs discordant and concordant for ASD in comparison with TD pairs (p = .02). Our results are in concordance with earlier findings that postzygotic de novo CNV events are typically rare in genomic DNA derived from saliva or blood, and suggests that the discordance of NDDs in our sample of twins is not explained by discordant CNVs. Still, studies investigating postzygotic variation in MZ discordant twins using DNA from different tissues and single cells and higher resolution genomics are needed in the future.
In: Twin research and human genetics: the official journal of the International Society for Twin Studies (ISTS) and the Human Genetics Society of Australasia, Band 24, Heft 4, S. 217-227
AbstractTwin studies can help us understand the relative contributions of genes and environment to phenotypic trait variation, including attentional and brain activation measures. In terms of applying methodologies such as electroencephalography (EEG) and eye tracking, which are key methods in developmental neuroscience, infant twin studies are almost nonexistent. Here, we describe the Babytwins Study Sweden (BATSS), a multi-method longitudinal twin study of 177 MZ and 134 DZ twin pairs (i.e., 622 individual infants) covering the 5−36 month time period. The study includes EEG, eye tracking and genetics, together with more traditional measures based on in-person testing, direct observation and questionnaires. The results show that interest in participation in research among twin parents is high, despite the comprehensive protocol. DNA analysis from saliva samples was possible in virtually all participants, allowing for both zygosity confirmation and polygenic score analyses. Combining a longitudinal twin design with advanced technologies in developmental cognitive neuroscience and genomics, BATSS represents a new approach in infancy research, which we hope to have impact across multiple disciplines in the coming years.
In: Twin research and human genetics: the official journal of the International Society for Twin Studies (ISTS) and the Human Genetics Society of Australasia, Band 14, Heft 6, S. 495-508
The Child and Adolescent Twin Study in Sweden (CATSS) is an ongoing longitudinal twin study targeting all twins born in Sweden since July 1, 1992. Since 2004, parents of twins are interviewed regarding the children's somatic and mental health and social environment in connection with their 9th or 12th birthdays (CATSS-9/12). By January 2010, 8,610 parental interviews concerning 17,220 twins had been completed, with an overall response rate of 80%. At age 15 (CATSS-15) and 18 (CATSS-18), twins and parents complete questionnaires that, in addition to assessments of somatic and mental health, include measures of personality development and psychosocial adaptation. Twin pairs in CATSS-9/12 with one or both twins screening positive for autism spectrum disorders, attention deficit/hyperactivity disorder, tic disorders, developmental coordination disorder, learning disorders, oppositional defiant disorder, conduct disorder, obsessive–compulsive disorder, and/or eating problems have been followed with in-depth questionnaires on family, social environment and personality, and subsequently by clinical assessments at age 15 together with randomly selected population controls, including 195 clinically assessed twin pairs from the first 2 year cohorts (CATSS-15/DOGSS). This article describes the cohorts and study groups, data collection, and measures used. Prevalences, distributions, heritability estimates, ages at onset, and sex differences of mental health problems in the CATSS-9/12, that were analyzed and found to be overall comparable to those of other clinical and epidemiological studies. The CATSS study has the potential of answering important questions on the etiology of childhood mental health problems and their role in the development of later adjustment problems.
In: Twin research and human genetics: the official journal of the International Society for Twin Studies (ISTS) and the Human Genetics Society of Australasia, Band 17, Heft 3, S. 164-176
Neurodevelopmental disorders affect a substantial minority of the general population. Their origins are still largely unknown, but a complex interplay of genetic and environmental factors causing disturbances of the central nervous system's maturation and a variety of higher cognitive skills is presumed. Only limited research of rather small sample size and narrow scope has been conducted in neurodevelopmental disorders using a twin-differences design. The Roots of Autism and ADHD Twin Study in Sweden (RATSS) is an ongoing project targeting monozygotic twins discordant for categorical or dimensional autistic and inattentive/hyperactive-impulsive phenotypes as well as other neurodevelopmental disorders, and typically developing twin controls. Included pairs are 9 years of age or older, and comprehensively assessed for psychopathology, medical history, neuropsychology, and dysmorphology, as well as structural, functional, and molecular brain imaging. Specimens are collected for induced pluripotent (iPS) and neuroepithelial stem cells, genetic, gut bacteria, protein-/monoamine, and electron microscopy analyses. RATSS's objective is to generate a launch pad for novel surveys to understand the complexity of genotype-environment-phenotype interactions in autism spectrum disorder and attention-deficit hyperactivity disorder (ADHD). By October 2013, RATSS had collected data from 55 twin pairs, among them 10 monozygotic pairs discordant for autism spectrum disorder, seven for ADHD, and four for other neurodevelopmental disorders. This article describes the design, recruitment, data collection, measures, collected pairs' characteristics, as well as ongoing and planned analyses in RATSS. Potential gains of the study comprise the identification of environmentally mediated biomarkers, the emergence of candidates for drug development, translational modeling, and new leads for prevention of incapacitating outcomes.
Individuals with special education needs have been particularly affected by the COVID-19 pandemic as they have been shown to be at high risk of losing medical and institutional support at a time when people are being asked to stay isolated, suffering increased anxiety and depression as a consequence. Their families have often found themselves under tremendous pressure to provide support, engendering financial hardship, and physical and emotional strains. In such times, it is vital that international collaborations assess the impact on the individuals and their families, affording the opportunity to make national and international comparisons of how people have coped and what needs to be done to optimize the measures taken by families, associations and governments. This paper introduces one such collaboration.