<qa>  What is the impact of sleep disturbances on the effectiveness of behavioral and education interventions?Autism Spectrum Disorders Autistic Disorder, Pervasive Developmental Disorder, Asperger Disorder are severe developmental disorders of early childhood onset affecting as many as 1 in 150 children Center for Disease Control Prevention, 2007. They characterized by deficits in social interaction and communication, as well as repetitive behavior and restricted interests American Psychiatric Association, 2000. Given the severity and the prevalence, autism is a significant public health issue. Recent years have seen both an increase in the prevalence of autism and an improved ability to diagnose the disorder much earlier Fombonne, 2003. It is during the childs early years when it is generally agreed that intensive interventions are most likely to improve long term prognosis National Research Council, 2001. While not a core feature of autism, it is widely accepted that a large percentage children with autism spectrum disorders autism present with significant sleep issues Honomichl, Goodlin-Jones, Burnham, Gaylor Anders, 2002; Johnson, 1996; Wiggs Stores, 2004. Sleep problems in typically developing children are known to adversely impact daytime functioning, learning acquisition, as well as parenting and family functioning Dahl, 1996; Ebert Drake, 2004; Sadeh, Gruber, Raviv; 2002; Sadeh, Raviv, Gruber, 2000. For young children with autism whose development is already compromised by a range of deficits, the detrimental impact of sleep disturbances may be even more significant. However, the impact of sleep disturbances on optimal performance in behavioral and education interventions have not been systematically explored. 