Early diagnosis of autism spectrum disorders

Autistic spectrum disorders (ASD) are an often-disabling continuum of disorders affecting two to four in 1000 children. These disorders have a core set of defining features including impaired verbal and nonverbal communication, impaired social interaction, and restricted or repetitive patterns of behavior. The cause of autism is unclear. The disorder can be defined only by related behaviors. Although there has been considerable improvement in standardized screening techniques for ASD in the past 10 years, screening and diagnostic practices in medicine and education lag far behind clinical research. Various studies have found the average age of diagnosis to be between 3 and 6 years, with significant differences as a function of ethnicity and socio-economic status. Preliminary research suggests that in some populations, missed diagnosis and misdiagnosis of ASD are common. This may be caused partly by inadequate screening practices. It also may reflect that presentation of symptoms varies from patient to patient. Lack of resources for appropriate referral, diagnosis, and treatment may play an important role. This article discusses recent progress in ASD screening, what is known of current screening and diagnostic practices, and future directions for research and practice improvement. The best practice model for the screening and early diagnosis of autism spectrum disorders and other developmental disabilities should include routine developmental surveillance as part of well-child pediatric care. General developmental screening should be followed by autism-specific screening for those children who fail the initial developmental screen, or whose parents report suspect behaviors. Copyright © 2004 by Current Science Inc.