Background Models of Autism Spectrum Disorders (ASD) as neural dysconnection syndromes have been predominantly supported by examinations of abnormalities in cortico-cortical networks in adults with autism. A broader body of research implicates subcortical structures, particularly the striatum, in the physiopathology of autism. Resting state fMRI has revealed detailed maps of striatal circuitry in healthy and psychiatric populations, and vividly captured maturational changes in striatal circuitry during typical development. Methods Using resting state fMRI, we examined striatal functional connectivity in 20 children with ASD and 20 typically developing children (TDC) between the age of 7.6 and 13.5 years. Whole-brain voxel-wise statistical maps quantified within-group striatal FC and between-group differences for three caudate and three putamen seeds, for each hemisphere. Results Children with ASD mostly exhibited prominent patterns of ectopic striatal functional connectivity (i.e., functional connectivity present in ASD but not in TDC), with increased functional connectivity between nearly all striatal subregions and heteromodal associative and limbic cortex previously implicated in the physiopathology of ASD (e.g., insular and right superior temporal gyrus). Additionally, we found striatal functional hyperconnectivity with the pons, thus expanding the scope of functional alterations implicated in ASD. Secondary analyses revealed ASD-related hyperconnectivity between the pons and insular cortex. Conclusions Examination of functional connectivity of striatal networks in children with ASD revealed abnormalities in circuits involving early developing areas such as the brainstem and insula, with a pattern of increased functional connectivity in ectopic circuits that likely reflects developmental derangement rather than immaturity of functional circuits.

We examined to what extent increased parent reports of autistic traits in some children with Attention Deficit Hyperactivity Disorder (ADHD) are the result of ADHD-related symptoms or qualitatively similar to the core characteristics of autism spectrum disorders (ASD). Results confirm the presence of a subgroup of children with ADHD and elevated ratings of core ASD traits (ADHD+) not accounted for by ADHD or behavioral symptoms. Further, analyses revealed greater oppositional behaviors, but not ADHD severity or anxiety, in the ADHD+ subgroup compared to those with ADHD only. These results highlight the importance of specifically examining autistic traits in children with ADHD for better characterization in studies of the underlying physiopathology and treatment.

Objective: Individuals with Attention-Deficit/Hyperactivity Disorder (ADHD) are often characterized as inconsistent across many contexts. ADHD is also associated with deficits in executive function. We examined the relationships between response time variability on five brief computer tasks to parents’ ratings of ADHD-related features and executive function in a group of children with a broad range of ADHD symptoms from none to full diagnosis. Methods: We tested 98 children (mean age 9.9±1.4 yrs; 66 boys) from community clinics on short Tasks of Executive Control (TEC) and the Eriksen Flanker Task, while a parent completed the Conners Parent Rating Scale and Behavior Rating Inventory of Executive Function. Results: Variability for two of the TEC tasks explained significant proportions of the variance of all five ADHD-related Conners subscales and several executive function subscales. By contrast, variability on the flanker task or mean response times for any task were not associated with any rating scale. Conclusions: The significant dimensional relationships observed between variability measures and parent ratings support the utility of response time variability as an objective measure in ADHD and aspects of executive functioning that is superior to response time means or accuracy measures.

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