Le nombre de symptômes de type autistique : quelle est leur place dans le processus de développement ?

Neurocognitive development in early childhood is a process that can predict the development of social, emotional, and cognitive skills that would allow a child to make a successful transition in a formal school environment. However, it is possible that neurocognitive development is hindered by behaviors that are associated with psychopathology. Furthermore, such symptoms are continuously distributed to various degrees in the general population (DiMartino et al., 2009). As in any psychopathology, autism spectrum disorder (ASD) can have symptoms that are mild and within normative parameters to more severe symptoms that actually cause functional impairment. However, past research has often involved children with ASD rather than using community-based samples. Having no ASD diagnosis does not preclude the presence of early ASD symptoms. Through two studies that involve a community-based sample, the current dissertation attempted to determine if the number of early ASD symptoms can be both an outcome and a risk factor for other variables in child development during the first three years. In the first study, we assessed the association between sleep quality indicators at 12 months and the number of early ASD symptoms at 24 months. This study revealed that the number of night wakings is significantly associated with the subsequent number of early ASD symptoms. However, child socio-emotional competence at 12 months makes a greater relative contribution than any sleep quality indicator even if the former variable was controlled. Lesser infant socio-emotional competence predicts a higher number of subsequent ASD symptoms. In the second study, the number of early ASD symptoms at 24 months acted as a predictor of child social, emotional, and cognitive maturity at 36 months.  Results reveal that children who showed more early ASD symptoms are at risk of developing a lower subsequent developmental maturity. Furthermore, maternal stress levels at 24 months of age act as a moderator of the observed association. Specifically, we observed that higher maternal stress levels interact with the number of early ASD symptoms to amplify the association between the latter and subsequent developmental maturity. In conclusion, both studies presented in this dissertation show a longitudinal link between the number of early ASD symptoms, child psychological development, and the role of parenting stress. They support the importance of assessing early ASD symptoms as a quantitative entity in children coming from the general population. Results further suggest the importance of implementing systematic ASD screening, which would help psychoeducators to identify needs for each child earlier before intervention services are provided. Finally, any intervention plan will have to include means that help worried parents to feel less under stress as success for any intervention plan is not possible without parents being involved as intervention partners.

Keyphrases: Autism spectrum disorders, Screening, Infant sleep, Sleep, Night wakings, Sleep onset latency, Socio-emotional-cognitive maturity, Developmental psychopathology