Rural communities face significant challenges regarding the adequate availability of diagnostic-, treatment-, and support-services for individuals with autism spectrum disorder (ASD). Specifically, a variety of factors, including geographic distance between families and service providers, low reliance on health care professionals, and cultural characteristics, contribute to the diminished availability and utilization of services. Together, these factors lead to risks for delayed ASD screening and diagnosis, yielding lower educational and functional outcomes. The purpose of this review is to outline the specific diagnosis and treatment barriers that affect individuals with ASD and their families in rural settings. Telehealth feasibility and efficacy research is also reviewed, suggesting that telecommunication services may offer an inroad for addressing the specific service barriers faced by rural communities. Together, the current review identifies specific needs for both research and support services that address the specific access barriers characteristic of rural settings.

Background Early brain overgrowth (EBO) in autism spectrum disorder (ASD) is amongst the best-replicated biological associations in psychiatry. Most positive reports have compared head circumference (HC) in ASD (an excellent proxy for early brain size) with well-known reference norms. We sought to reappraise evidence for the EBO hypothesis given (i) the recent proliferation of longitudinal HC studies in ASD, and (ii) emerging reports that several of the reference norms used to define EBO in ASD may be biased towards detecting HC overgrowth in contemporary samples of healthy children. Methods (1)Systematic review of all published HC studies in children with ASD. (2)Comparison of 330 longitudinally gathered HC measures between birth and 18 months from male children with autism(n=35) and typically developing controls(n=22). Results In systematic review, comparisons with locally recruited controls were significantly less likely to identify EBO in ASD than norm-based studies(p<0.006). Through systematic review and analysis of new data we replicate seminal reports of EBO in ASD relative to classical HC norms, but show that this overgrowth relative to norms is mimicked by patterns of HC growth age in a large contemporary community-based sample of US children(n~75,000). Controlling for known HC norm biases leaves inconsistent support for a subtle, later-emerging and sub-group specific pattern of EBO in clinically-ascertained ASD vs. community controls. Conclusions The best-replicated aspects of EBO reflect generalizable HC norm biases rather than disease-specific biomarkers. The potential HC norm biases we detail are not specific to ASD research, but apply throughout clinical and academic medicine.

BackgroundNeurobiological research in autism spectrum disorders (ASD) has paid little attention on brain mechanisms that cause and maintain restricted and repetitive behaviors and interests (RRBIs). Evidence indicates an imbalance in the brain’s reward system responsiveness to social and non-social stimuli may contribute to both social deficits and RRBIs. Thus, this study’s central aim was to compare brain responsiveness to individual RRBI (i.e., circumscribed interests), with social rewards (i.e., social approval), in youth with ASD relative to typically developing controls (TDCs).MethodsWe conducted a 3T functional magnetic resonance imaging (fMRI) study to investigate the blood-oxygenation-level-dependent effect of personalized circumscribed interest rewards versus social rewards in 39 youth with ASD relative to 22 TDC. To probe the reward system, we employed short video clips as reinforcement in an instrumental incentive delay task. This optimization increased the task’s ecological validity compared to still pictures that are often used in this line of research.ResultsCompared to TDCs, youth with ASD had stronger reward system responses for CIs mostly within the non-social realm (e.g., video games) than social rewards (e.g., approval). Additionally, this imbalance within the caudate nucleus’ responsiveness was related to greater social impairment.ConclusionsThe current data support the idea of reward system dysfunction that may contribute to enhanced motivation for RRBIs in ASD, accompanied by diminished motivation for social engagement. If a dysregulated reward system indeed supports the emergence and maintenance of social and non-social symptoms of ASD, then strategically targeting the reward system in future treatment endeavors may allow for more efficacious treatment practices that help improve outcomes for individuals with ASD and their families.Electronic supplementary materialThe online version of this article (10.1186/s13229-018-0195-7) contains supplementary material, which is available to authorized users.

Previous work has found gender differences in restricted and repetitive behaviors and interests (RRBI) for autism spectrum disorder (ASD). Compared to girls, affected boys have increased stereotyped and restricted behaviors; however much less is known about gender differences in other areas of RRBI. This study aims to identify whether specific RRBI (i.e., stereotyped, self‐injurious, compulsive, insistence on sameness, ritualistic, and restricted), as measured by item‐level data on the Repetitive Behavior Scale‐Revised (RBS‐R), can distinguish girls from boys with ASD. Participants included 615 individuals with ASD (507 boys; 82.4%), ages 3–18 years of age (M = 10.26, SD = 4.20), who agreed to share data with the National Database for Autism Research (NDAR). Multivariate analysis of variance and discriminant function analysis (DFA) were used to determine whether item‐level RBS‐R data could correctly classify cases by gender. DFA results suggest that RBS‐R items significantly differentiate gender. Strongly differentiating RBS‐R items had greater success in correctly classifying affected boys (67.90%) than girls (61.00%). Items that best‐discriminated gender were heightened stereotyped behaviors and restricted interests items in boys and compulsive, sameness, restricted, and self‐injurious behavior items in girls. This study is the first to find that girls with ASD may have increased compulsive, sameness, and restricted RRBI compared to boys. Additionally, findings support heightened self‐injurious behaviors in affected girls. Future research should disentangle whether elevated rates of RRBI in girls are central to the presentation of ASD in girls or an epiphenomenon of the high rates of co‐occurring disorders (e.g., anxiety) noted in girls. Autism Res 2019, 12: 274–283 © 2018 International Society for Autism Research, Wiley Periodicals, Inc. Lay Summary This study is the first to examine a comprehensive measure of repetitive behavior in children with autism, with findings of increased compulsive, insistence on sameness, and self‐injurious behavior characterizing girls and increased stereotyped and restricted behavior characterizing boys. Future research should determine whether these elevated behaviors in girls are directly part of the autism presentation in girls or symptoms of co‐occurring psychopathology. It is important for autism diagnostic measures to best capture the types of repetitive behavior girls may demonstrate.

Distorted empathic processing has been observed across multiple psychiatric disorders. Simulation theory provides a theoretical framework that proposes a mechanism through which empathy difficulties may arise. Specifically, introspection-centric simulation theory (IST) predicts that an inability to accurately interpret and describe internal affective states may lead to empathy difficulties. The purpose of this review is to synthesize and summarize an empirical literature suggesting that simulation theory provides insights into a cognitive and neurobiological mechanism (i.e., alexithymia and insula pathology) that negatively impacts empathic processing, in addition to how disruptions in these processes manifest across psychiatric disorders. Specifically, we review an emerging non-clinical literature suggesting that consistent with IST, alexithymia and associated insula pathology leads to empathy deficits. Subsequently, we highlight clinical research suggesting that a large number of disorders characterized by empathy pathology also feature alexithymia. Collectively, these findings motivate the importance for future work to establish the role of alexithymia in contributing to empathy deficits across clinical symptoms and disorders. The current review suggests that simulation theory provides a tractable conceptual platform for identifying a potential common cognitive and neural marker that is associated with empathy deficits across a wide array of diagnostic classes.

Autism spectrum disorder (ASD) is often associated with high levels of inflexible thinking and rigid behavior. The neural correlates of these behaviors have been investigated in adults and older adolescents, but not children. Prior studies utilized set-shifting tasks that engaged multiple levels of shifting, and depended on learning abstract rules and establishing a strong prepotent bias. These additional demands complicate simple interpretations of the results. We used functional magnetic resonance imaging (fMRI) to investigate the neural correlates of set-shifting in 20 children (ages 7-14) with ASD and 19 typically developing, matched, control children. Participants completed a set-shifting task that minimized non-shifting task demands through the use of concrete instructions that provide spatial mapping of stimuli-responses. The shift/stay sets were given an equal number of trials to limit the prepotent bias. Both groups showed an equivalent ‘switch cost’, responding less accurately and slower to Switch stimuli than Stay stimuli, although the ASD group was less accurate overall. Both groups showed activation in prefrontal, striatal, parietal, and cerebellum regions known to govern effective set-shifts. Compared to controls, children with ASD demonstrated decreased activation of the right middle temporal gyrus across all trials, but increased activation in the mid-dorsal cingulate cortex/superior frontal gyrus, left middle frontal and right inferior frontal gyri during the Switch vs. Stay contrast. The successful behavioral switching performance of children with ASD comes at the cost of requiring greater engagement of frontal regions, suggesting less efficiency at this lowest level of shifting.

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Background: Children with autism spectrum disorder (ASD) and co-occurring attention deficit/ hyperactivity disorder (ADHD) symptoms have worse functional outcomes and treatment response than those without ADHD symptoms. Here we test the hypothesis that aberrant functional connectivity of two large-scale executive brain networks implicated in ADHD-the frontoparietal and salience/ventral attention networks-also play a role in ADHD symptoms in ASD. Methods: We compared resting-state functional connectivity of the two executive brain networks in children with ASD (n=77) and typically developing controls (n=82). These two executive brain networks are comprised of five sub-networks (three fronto-parietal, two salience/ventral attention). After identifying aberrant functional connections among subnetworks, we examined dimensional associations with parent-reported ADHD symptoms. Results: Weaker functional connectivity in ASD was present within and between fronto-parietal and salience/ventral attention sub-networks. Decreased functional connectivity within a single salience/ventral attention sub-network, as well as between two fronto-parietal sub-networks, significantly correlated with ADHD symptoms. Furthermore, follow-up linear regressions demonstrated that the salience/ventral attention and fronto-parietal sub-networks explain unique variance in ADHD symptoms. These executive brain network-ADHD symptom relationships remained significant after controlling for ASD symptoms. Finally, specificity was also demonstrated through the use of a control brain network (visual) and a control comorbid symptom domain (anxiety). Conclusion: The present findings provide novel evidence that both fronto-parietal and salience/ ventral attention networks' weaker connectivities are linked to ADHD symptoms in ASD. Moreover, co-occurring ADHD in the context of ASD is a source of meaningful neural heterogeneity in ASD.