Diagnostic assessment of communicative and interactive behaviours in children with autism and receptive language disorder.

Children with autism and children with a severe specific receptive language disorder both show clear deficits in communicative language skills and in social relationships. In this study the usefulness of the Autism Diagnostic Observation Schedule (ADOS) in the differential diagnosis between these two groups of developmentally impaired children is assessed. 11 children with early infantile autism and 20 children with a specific receptive language disorder participated in the study. 18 children with an expressive language disorder were used as a control group. The ADOS was individually administered to all children by the same examiner. The results showed that on most of the ADOS measures the autistic children were clearly more deviant than the language impaired children. There were no significant differences between the two groups of language impaired children. Eight out of 11 autistic children reached the defined cut-off values on the measures "language and communication" and "social interaction" of the ADOS algorithm, whereas only three autistic children did so on the measure "stereotyped behaviour". None of the language-impaired children reached the cut-off values on more than one measure. The ADOS allowed for good assessment of certain types of behaviour. However, to confirm the diagnosis of infantile autism, additional information from parents is required.