Characterization of early skill profiles for infants across varying genetic likelihoods for neurodevelopmental disorders.

Several infant behaviors spanning multiple developmental domains have been identified as promising markers of early neurodivergence, such as ADHD or ASD. Some of these early markers include social-communication differences, atypical attention, and motor deficits. Research involving early predictors of ADHD features in infants is scarcer than research involving early predictors of ASD. However, studies among school-age children have observed comparable profiles of language, attention, and motor skills between children with ASD and children with ADHD. Given that assessing early features of ASD and ADHD is fundamental to increasing earlier diagnoses, this study examined parent-reported social-communication, attention, and motor profiles across 12-month-old infants at elevated genetic likelihoods for ASD (EL-ASD) and ADHD (EL-ADHD), and low genetic likelihood for either disorder (LL). Parent responses on the CSBS-CG, FYI, and EMQ were compared across the three groups. Results showed EL-ASD participants as scoring lower than both LL and EL-ADHD participants on parent-reported social skills and attention constructs (Responding to and Initiating Social Attention). Although FYI constructs are meant to measure attention, the Responding to and Initiating Social Attention subscales also include aspects of social communication. Differences between EL-ADHD and LL infants on measures of social-communication, motor, and attention skills were not observed, suggesting that parent-reported differences between EL-ADHD and LL infants' behavior may not be as detectable during infancy as those associated with ASD. Future research is required to further the understanding of developmental differences of infants with features of ADHD.