DSM-IV-defined Asperger Syndrome: cognitive, behavioural, and early history differentiation from high-functioning autism

By Sally Ozonoff, Mike South, and Judith N. Miller (2000) autism, 4, 29-46.

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This study compared 23 children with high-functioning autism with 12 children with Asperger syndrome, both defined according to strict DSM-IV diagnostic criteria. The groups were well matched on chronological age, gender, and intellectual ability. Three possible sources of difference between Asperger syndrome and high-functionaing autism were examined: cognitive function, current symptomatology, and early history. We found few group differences in current presentation and cognitive functions, but many early history differences. The Asperger syndrome group generally demonstrated less severe early symptoms, a milder developmental course, and better outcome than the high-functioning autism group ... Overall, the results suggest that Asperger syndrome and high-functioning autism involve the same fundamental symptomatology, differing only in degree or severity.

The group differences in imagination and repetitive behaviour found in this study merit further exploration and may perhaps provide some evidence of external validity for the Asperger syndrome label in the future, if replicated. It is just as dangerous, and just as poor science, to prematurely discard the Asperger syndrome label as it is to unequivocally endorse it before all the data are in.