The Behavioural and Developmental Continuum of Autism Interventions: A Systematic Review

Background: Considering the importance of, and demand for interventions for ASD, and the current rising trend in new programmes, a rigorous synthesis of high quality intervention is needed to inform the clinical community, policy makers, researchers, and families of children with autism. Objectives: To review and synthesize the evidence on the efficacy and effectiveness of the behavioural and developmental continuum of interventions for autism. Methods: Comprehensive searches were conducted in 22 electronic data bases of medical and psychological literature up to May 2007. Other sources of potentially relevant studies included hand searches of relevant journals, reference tracking, and contact with experts. Included studies were clinical trials and observational analytical studies on any behavioural or developmental intervention for individuals diagnosed with autism and published in English. Two independent reviewers assessed study relevance, extracted the data, and assessed the methodological quality of the studies. Results: Evidence on the effectiveness of interventions was provided in 101 studies that were predominantly of poor to moderate methodological quality.The substantial variations among the studies in the the design, the description of the interventions, the type of controls, the type of populations, and the outcomes reported allowed for direct comparisons of only 13 of the 101 studies included in the review. Conclusions: In spite of the many published studies on the subject, there remains deep controversy and no definitive answer regarding the "best" approach to treat the core symptoms and other manifestations of autism. Management decisions need to be guided by individual clinical presentation, needs of the caregivers, and availability of resources for implementation of the intervention. Future studies on effectiveness of these interventions need to be more rigorous.