LAUSR

Understanding both for whom and how interventions work is a crucial next step in providing personalized care to children with autism spectrum disorder (ASD). Autistic children present with heterogeneity both within core ASD criteria and with respect to co‐occurring mental health challenges, which may affect their ability to benefit from intervention. In a secondary data analysis of a randomized control trial evaluating an executive function (EF) training with 70 7‐ to 11‐year‐old autistic children, we explored: (1) whether co‐occurring attention‐deficit/hyperactivity disorder (ADHD) features or anxiety features at baseline moderated the extent to which children benefited from the EF training. In other words, we asked, “For whom is training effective?” We also explored: (2) the extent to which changes in a brain‐based measure of target engagement predicted the clinical outcomes of the EF training. This is a step towards asking, “How is training effective?” We found that EF training improved behavioral inhibition only for children with clinically significant co‐occurring ADHD features. Anxiety features, while prevalent, did not moderate EF training efficacy. Finally, for the EF training group only, there was a significant correlation between pre‐to‐post change in an EEG‐based measure of target engagement, N2 incongruent amplitude during a flanker task, and change in repetitive behaviors, a behavioral outcome that was reported in the parent RCT to have improved with training compared to waitlist control. This study provides preliminary evidence that EF training may differentially affect subgroups of autistic children and that changes at the neural level may precede changes in behavior.