Abstract
The article reviews studies of early diagnosis of Autistic Spectrum Disorder. Currently, there are no objective measures that can be used for accurate diagnosis, and the diagnosis remains clinical. The article provides guidelines for evaluation.
SINCE FIRST described by Kanner,1 much has been learned about the diagnosis and treatment of the autism/pervasive developmental disorders (PDD). Initial reports suggested that prognosis was extremely poor, and children with autism/PDD were considered resistant to treatment. Autism/PDD is best viewed as a social-communication learning disability. Just as some children have trouble learning reading and math, children with autism/PDD have trouble learning social-communication skills. It is now well recognized that autism/PDD is a biologic disorder and that early intervention is effective. Therefore, since children with autism/PDD benefit from early intervention the need for early identification and diagnosis has become increasingly important.2 For the purposes of this article, Autistic Spectrum Disorder (ASD) will be used to encompass the range of PDDs with the exception of Rett's disorder.
In order to understand the early development of children with ASD, it is necessary to first understand how typical children develop. In the first 3 to 4 years of life, typical children make tremendous developmental strides. They learn how to regulate states of arousal, gain physical coordination, and develop increasing knowledge about persons and objects in the world. While individual physical growth patterns may vary, most typical children reach developmental milestones at an even rate, and all areas of development are intimately related. Early identification of ASD has been difficult because it involves disruption in multiple developmental pathways. Some of the symptoms are not readily apparent until a child is past 3 years of age, when his or her social opportunities increase. However, several studies3-6 using retrospective analysis of videotapes have reported that symptoms are present as early as 9 to 12 months of age. Diagnosis is complicated by the fact that the expression of the syndrome is extremely varied, ranging from children who are very severely affected to those who are very mildly affected. The focus of this article is to provide general clinical guidelines for evaluating young children who may present with social-communication delays consistent with ASD.