The association between reaction time variability and social problems in children with ADHD: support for the role of attentional fluctuations in social interactions

Children with attention-deficit/hyperactivity disorder (ADHD) typically experience social interaction problems. Neurocognitive functions, such as working memory and inhibitory control have been included in several studies of social problems in ADHD, with inconsistent findings emerging. Intraindividual reaction time variability (RTV) has been understudied as a factor explaining social problems in children with ADHD, despite being one of the most consistent cognitive impairments in the disorder. In the current study, we hypothesized that greater RTV would relate to greater parent-reported social problems and may reflect the negative impact of attentional fluctuations on social interactions in ADHD. We tested the association between RTV and social problems while accounting for the effects of working memory and inhibitory control in two independent samples of children with ADHD and typically developing (TD) peers. The neurocognitive functions were assessed through performance-based laboratory measures. Sample one, derived in Norway, included 41 children with ADHD and 35 TD children. Sample two, derived in the United States, included 73 children with ADHD and 26 TD children. Linear regression analyses, controlling for other relevant variables, indicated that greater RTV was associated with greater social problems across both samples. Our results support the view that attentional variability is linked to social problems in children with ADHD.