The onset of Autistic Spectrum Disorders (ASD) is detected in the first years of life. Early intensive behavioural intervention has been identified as important in the care and treatment of persons with autistic spectrum disorders, according to the 1999 practice parameters for assessment and treatment by the American Academy of Child and Adolescent Psychiatry. The New York State Department of Health’s Early Intervention Program published Clinical Practice Guidelines in 1999 that recommends intensive behavioural and educational programs based on the best scientific evidence available. The National Research Council has also endorsed early intervention in its recent publication entitled Educating Children with Autism. A committee was formed by the National Research Council to integrate the existing scientific, theoretical and policy evidence on Educational Interventions for Children with Autism. They focused on early intervention for children with ASD from age birth to 8 years. The committee recommended “children with an Autistic Spectrum Disorder regardless of severity or function, be eligible for special education services.” (National Research Council, 2001. p.3), although they recognized that children with ASD vary a great deal in terms of the severity of symptoms and the involvement of different developmental domains.

There have been 3 consistent findings in the evidence-based research literature on early intensive behavioural intervention. First, there is agreement that children diagnosed with an Autistic Spectrum Disorder need to enter a program at an early age, before age 4. The National Research Council report went a step further recommending that children receive early intervention as soon as an Autistic Spectrum Disorder is suspected. Second, programming needs to last for 2 or more years. Third, programming needs to be intensive. Effective interventions consisted of between 20 and 40 hours of treatment each week. The National Research Council recommended a minimum of 25 hours per week or a full school day, for 12 months of the year.

Dawson and Osterling (1997) reviewed early intensive behavioural intervention studies that were effective with young children with ASD, and they found many common characteristics. The similarities included intensive one-to-one instruction using behavioural principles, with systematic programmes for both learning new skills and generalizing the acquired skills to other people, places and materials. A comprehensive developmental curriculum across all developmental domains was typically utilized and instruction typically began with attending skills and imitation skills. Once these were mastered communication, visual discrimination, self-help and social skills were taught. Learning environments were consistent, structured and predictable, therapists were trained and supervised on an ongoing basis, and families were involved with setting goals as well as working with their child both in treatment with supervision and outside of therapy times to provide additional intervention. The programs supported the transition to school and inclusion with typical peers. Dawson and Osterling noted a few differences between the early intensive behavioural interventions. Settings varied from contrived, individual settings to more naturalistic environments such as group child care settings. Some programs focused more on cognitive skill development, while others focused on social communication skill outcomes.

The evidence to date shows that intensive intervention based on the principles of applied behaviour analysis is a recommended “best practice” for treatment of young children with ASD. This recommendation is based on a comprehensive review of the best scientific evidence available. Impressive developmental gains have been reported and, this foundation helps to guide our clinical judgment, yet many questions remain unanswered. Little is known about the many aspects of early behavioural intervention such as the intensity, settings and curriculum. Research is needed to compare the effectiveness of different forms of early behavioural treatments. More study is needed to understand the interaction between behavioural intervention, and the characteristics of the children involved in the treatment and their families.

Fortunately we have the opportunity to begin to examine some of these important questions by evaluating existing progranmmes of early intensive behavioural intervention in Ontario, funded by the Ministry of Community, Family and Children Services. The inspiration to understand the impact of early intensive behavioural intervention on the development of young children with ASD stems from the children and families we encounter in our work.