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.