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Background: Reward processing has been proposed to underpin the atypical social feature of autism spectrum disorder (ASD). However, previous neuroimaging studies have yielded inconsistent results regarding the specificity of atypicalities for social reward processing in ASD. Aims: Utilising a large sample, we aimed to assess reward processing in response to reward type (social, monetary) and reward phase (anticipation, delivery) in ASD. Method: Functional magnetic resonance imaging during social and monetary reward anticipation and delivery was performed in 212 individuals with ASD (7.6–30.6 years of age) and 181 typically developing participants (7.6–30.8 years of age). Results: Across social and monetary reward anticipation, whole-brain analyses showed hypoactivation of the right ventral striatum in participants with ASD compared with typically developing participants. Further, region of interest analysis across both reward types yielded ASD-related hypoactivation in both the left and right ventral striatum. Across delivery of social and monetary reward, hyperactivation of the ventral striatum in individuals with ASD did not survive correction for multiple comparisons. Dimensional analyses of autism and attention-deficit hyperactivity disorder (ADHD) scores were not significant. In categorical analyses, post hoc comparisons showed that ASD effects were most pronounced in participants with ASD without co-occurring ADHD. Conclusions: Our results do not support current theories linking atypical social interaction in ASD to specific alterations in social reward processing. Instead, they point towards a generalised hypoactivity of ventral striatum in ASD during anticipation of both social and monetary rewards. We suggest this indicates attenuated reward seeking in ASD independent of social content and that elevated ADHD symptoms may attenuate altered reward seeking in ASD. [ABSTRACT FROM AUTHOR]

There is mixed evidence on the association between headache and attention-deficit/hyperactivity disorder (ADHD), as well as headache and ADHD medications. This systematic review and meta-analysis investigated the co-occurrence of headache in children with ADHD, and the effects of ADHD medications on headache. Embase, Medline and PsycInfo were searched for population-based and clinical studies comparing the prevalence of headache in ADHD and controls through January 26, 2021. In addition, we updated the search of a previous systematic review and network meta-analysis of double-blind randomized controlled trials (RCTs) on ADHD medications on June 16, 2020. Trials of amphetamines, atomoxetine, bupropion, clonidine, guanfacine, methylphenidate, and modafinil with a placebo arm and reporting data on headache as an adverse event, were included. Thirteen epidemiological studies and 58 clinical trials were eligible for inclusion. In epidemiological studies, a significant association between headache and ADHD was found [odds ratio (OR) = 2.01, 95% confidence interval (CI) = 1.63–2.46], which remained significant when limited to studies reporting ORs adjusted for possible confounders. The pooled prevalence of headaches in children with ADHD was 26.6%. In RCTs, three ADHD medications were associated with increased headache during treatment periods, compared to placebo: atomoxetine (OR = 1.29, 95% CI = 1.06–1.56), guanfacine (OR = 1.43, 95% CI = 1.12–1.82), and methylphenidate (OR = 1.33, 95% CI = 1.09–1.63). The summarized evidence suggests that headache is common in children with ADHD, both as part of the clinical presentation as such and as a side effect of some standard medications. Monitoring and clinical management strategies of headache in ADHD, in general, and during pharmacological treatment are recommended. [ABSTRACT FROM AUTHOR]

While neurodevelopmental disorders (NDDs) are highly heritable, several environmental risk factors have also been suggested. However, the role of familial confounding is unclear. To shed more light on this, we reviewed the evidence from twin and sibling studies. A systematic review was performed on case control and cohort studies including a twin or sibling within-pair comparison of neurodevelopmental outcomes, with environmental exposures until the sixth birthday. From 7,315 screened abstracts, 140 eligible articles were identified. After adjustment for familial confounding advanced paternal age, low birth weight, birth defects, and perinatal hypoxia and respiratory stress were associated with autism spectrum disorder (ASD), and low birth weight, gestational age and family income were associated with attention-deficit/hyperactivity disorder (ADHD), categorically and dimensionally. Several previously suspected factors, including pregnancy-related factors, were deemed due to familial confounding. Most studies were conducted in North America and Scandinavia, pointing to a global research bias. Moreover, most studies focused on ASD and ADHD. This genetically informed review showed evidence for a range of environmental factors of potential casual significance in NDDs, but also points to a critical need of more genetically informed studies of good quality in the quest of the environmental causes of NDDs. [ABSTRACT FROM AUTHOR]

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

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. [ABSTRACT FROM AUTHOR]

The article focuses on the association between caffeine consumption, ADHD, and pediatric headaches. Topics include increased caffeine consumption and its potential role in self-medication for ADHD symptoms, caffeine withdrawal headache in children and adolescents, and the mechanisms of caffeine-associated headaches, including adenosine receptor up-regulation and interference with the circadian system.

Background: Mortality has been suggested to be increased in autism spectrum disorder (ASD).Aims: To examine both all-cause and cause-specific mortality in ASD, as well as investigate moderating role of gender and intellectual ability.Method: Odds ratios (ORs) were calculated for a population-based cohort of ASD probands (n = 27,122, diagnosed between 1987 and 2009) compared with gender-, age- and county of residence-matched controls (n = 2,672,185).Results: During the observed period, 24,358 (0.91%) individuals in the general population died, whereas the corresponding figure for individuals with ASD was 706 (2.60%; OR = 2.56; 95% CI 2.38-2.76). Cause-specific analyses showed elevated mortality in ASD for almost all analysed diagnostic categories. Mortality and patterns for cause-specific mortality were partly moderated by gender and general intellectual ability.Conclusions: Premature mortality was markedly increased in ASD owing to a multitude of medical conditions. [ABSTRACT FROM AUTHOR]

Background: Autism spectrum disorder (ASD) is linked to social brain activity and facial affect recognition (FAR).Aims: To examine social brain plasticity in ASD.Method: Using FAR tests and functional magnetic resonance imaging tasks for FAR, we compared 32 individuals with ASD and 25 controls. Subsequently, the participants with ASD were assigned to FAR computer-aided cognitive training or a control group.Results: The ASD group performed more poorly than controls on explicit behavioural FAR tests. In the scanner, during implicit FAR, the amygdala, fusiform gyrus and other regions of the social brain were less activated bilaterally. The training group improved on behavioural FAR tests, and cerebral response to implicit affect processing tasks increased bilaterally post-training in the social brain.Conclusions: Individuals with ASD show FAR impairments associated with hypoactivation of the social brain. Computer-based training improves explicit FAR and neuronal responses during implicit FAR, indicating neuroplasticity in the social brain in ASD. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM PUBLISHER]

Research on acoustic communication and its underlying neurobiological substrates has led to new insights about the functioning of central pattern generators (CPGs). CPG-related atypicalities may point to brainstem irregularities rather than cortical malfunctions for early vocalizations/babbling. The “vocal pattern generator,” together with other CPGs, seems to have great potential in disentangling neurodevelopmental disorders and potentially predict neurological development. [ABSTRACT FROM PUBLISHER]