A cross-syndrome approach to atypical development: Modelling developmental trajectories in children with autism spectrum disorder, attention deficit and hyperactivity disorder and callous-unemotional traits.
The key goal of this proposal is to test whether observed overlap in symptoms of autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD) and callous-unemotional (CU) traits can result from both shared and distinct underlying developmental pathways. To test this hypothesis, I will compare infant social and attentional trajectories by applying advanced statistical methods to existing data from two longitudinal studies: the Wirral Child Health and Development Study (WCHADS) and the British Autism Study of Infant Siblings (BASIS), and newly collected experimental (eye-tracking) and questionnaire data. Study 1 tests the hypothesis that recognising emotional faces will be impaired in 6-year-olds with high ASD- and CU-traits, but infant precursors to social-affective impairment (e.g. face tracking) will differ across traits. Study 2 will test whether executive functions act as protective factors in ASD- and ADHD-traits, through interactions with the catechol-O-methyltr ansferase Val108/158Met polymorphism and behavioural habituation. The final study combines data from BASIS and WCHADS using integrative data analysis techniques in order to compare evidence for cumulative models, in which risk markers work additively to predict outcome, and cascading models, where risk factors interact over development. Characterising developmental origins, rather than just symptomatology, has important relevance for the long-term development of intervention strategies.