Abstract:
Autism spectrum disorder (ASD) is a pervasive developmental disorder that is characterised by deficits in social communication and restricted and repetitive behaviours, interests and activities. Recent developments in identification techniques mean that many children can be reliably diagnosed with ASD before the age of 2. Early identification creates the opportunity for early intervention. In fact, some research suggests that the earlier a child with ASD receives intervention, the greater the progress he or she is likely to make. Naturalistic developmental behavioural interventions are a relatively recent method of early intervention for children with ASD, which combine elements of previous intervention approaches (behavioural, naturalistic behavioural, and developmental/relationship-focused intervention). One such naturalistic developmental behavioural intervention is the early start Denver model (ESDM), which is designed for children with or at risk for ASD between the ages of 12 and 60 months (5 years). Research suggests that ESDM intervention may improve a range of child outcomes when delivered for at least 15 hours per week over at least 10 months. However, many families may not be able to access or afford such intensive intervention. Therefore, the two studies in this thesis evaluated the effectiveness of two ESDM delivery approaches that required relatively few hours of professional input per week. Specifically, low-intensity therapist delivered ESDM intervention, and ESDM parent training.
Study 1 used a multiple probe across participants design to evaluate the effectiveness of 3 hours per week of home-based ESDM therapy for 12 weeks for improving imitation, communication, and engagement for four young children with ASD. It also examined whether children showed increases in these outcomes with their mothers following the intervention. The results of this study suggest that, following the intervention, all four children increased their imitation skills and their engagement with the therapist. In addition three of the children had more functional utterances and one child increased his use of intentional vocalisations. These results were maintained four weeks after intervention and generalised to a lesser degree to each child’s mother. This suggests that low-intensity therapist delivered ESDM intervention may improve outcomes for children with ASD.
The results of Studies 1 and 2 suggest that both low-intensity therapist delivered ESDM intervention and ESDM parent training may be promising intervention approaches for young children with ASD. This is particularly encouraging as both approaches involved relatively few hours of professional input per week. In theory, this could increase the number of families who are able to access such intervention. More research is needed to identify the most effective low-intensity ESDM intervention method, or combination of methods.
