The comprehensiveness and severity of executive dysfunction in high-functioning autism (HFA) spectrum disorder have not reached a unified conclusion especially in patients in adulthood. Clarifying this issue is critical for guiding clinical diagnosis and targeted intervention. The primary objective of the present meta-analysis was to study the characteristics of executive function (EF) in adults with HFA compared to typically developing (TD) adults, by taking five key components into consideration, including inhibition, working memory, flexibility, planning, and fluency. The PubMed and Embase databases were searched to identify peer-reviewed studies that compared EF in adults with and without HFA from 1980 to November 2018. Hedges' g effect sizes were computed to measure the primary outcome. Moderators like age, sex, and diagnostic tools were controlled using meta-regressions. Forty-two studies satisfying the selection criteria were included, which resulted in a large sample size of 2419 participants. A moderate overall effect size for reduced EF across domains was found in adults with HFA, compared with TD (g = 0.57, 95% confidence interval 0.47-0.66). Subsequently, a broad executive dysfunction was found in adults with HFA in this study (flexibility [g = 0.69], planning [g = 0.64], inhibition [g = 0.61], working memory [g = 0.48], fluency [g = 0.42]), with the predominated impairment on flexibility and planning. Taken together, these results provide evidence for the executive dysfunction hypothesis and may assist in the clinical diagnosis and targeted intervention, suggesting the necessity of sustained intervention on EF for individuals with HFA from childhood to adulthood.

Background Although methylphenidate (MPH) and atomoxetine (ATX) can improve clinical symptoms and functional impairments in attention deficit/hyperactive disorder (ADHD), the underlying psychopharmacological mechanism have not been clearly elucidated. Therefore, we aimed to explore the shared and unique neurologic basis of these two medications in alleviating the clinical symptoms and functional impairments observed in ADHD. Methods Sixty-seven ADHD and 44 age-matched children with typical development were finally included and underwent resting-state functional magnetic resonance imaging (fMRI) scans at baseline. Then patients were assigned to MPH, ATX or untreated subgroups, based on the patients’ and their parents’ choice, for a 12-week follow-up, and underwent a second fMRI scan. The treatment effect on degree centrality (DC) was identified and correlated with clinical symptoms and functional impairments in the ADHD group. Results Both of MPH and ATX normalised the DC value in extensive brain regions mainly involving fronto-cingulo-parieto-cerebellum circuits. However, ATX showed limited significant effects on the cerebellum compared to ADHD at baseline. The improvements in clinical symptoms were correlated with increased DC in the right inferior temporal gyrus in both MPH and ATX subgroups, but showed opposite effects. The alleviation of functional impairments in the school/learning domain negatively correlated with decreased DC in the bilateral cerebellum after MPH treatment, while the family functional domain positively correlated with decreased DC in the cerebellum and negatively correlated with decreased DC in the postcentral gyrus after ATX treatment. Conclusions Both MPH and ATX can normalise abnormal brain functions that mainly involve the fronto-cingulo-parieto-cerebellum circuit in ADHD. Furthermore, the two medications affected shared and unique effective brain regions to alleviate clinical symptoms and functional impairment.

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IntroductionPreterm (PT) infants are at high likelihood for poor neurodevelopmental outcomes, including autism spectrum disorder (ASD), attention-deficit hyperactivity disorder (ADHD) and other neurodevelopmental disorders (NDDs), which could considerably impair the individuals’ functions throughout their whole life. The current cohort study aims to investigate adverse outcomes, especially NDDs, in PT children, and the related early aberrant brain developmental biomarkers.Methods and analysisThis is a prospective cohort study in Beijing, China. We plan to recruit 400 PT infants born at <37 weeks of gestational age (GA), and 200 full-term (FT) controls during the neonatal period (40 weeks corrected GA), then follow them up until they reach 6 years of age. This cohort is designed to assess neuropsychological functions, brain development, related environmental risk factors and the incidence of NDDs by using the following measures: (1) social, emotional, cognitive and sensorimotor functions; (2) MRI, electroencephalogram and functional near-infrared spectroscopy; (3) social economic status, maternal mental health and DNA methylation; and (4) symptoms and diagnosis of NDDs. Main data analyses will include comparing the neurodevelopment outcomes and brain developmental trajectories between PT and FT children using linear or logistic regressions and mixed-effects models. Regression analyses and machine learning will be used to identify early biological predictors and environmental risk or protective factors for later NDDs outcomes.Ethics and disseminationEthical approval has been obtained from the research ethics committee of Peking University Third Hospital (M2021087). This study is under review in the Chinese Clinical Trial Register. The study results from the current cohort will be disseminated and popularised through social media to participating parents, as well as parents who are giving care to PT children.