Early referral and diagnosis of Autism Spectrum Disorder present the clinical practice with the need for more knowledge of developmental course, outcome and early predictors of outcome.
This follow-up study investigate outcome in the form of cognitive abilities, symptom severity and adaptive functioning at age 11 years of children, who under the age of 4 were consecutively referred to at child and adolescent psychiatric clinic with a suspicion of Autism Spectrum Disorders. Early predictors of these outcome measures are also investigated.
23 of 30 children were followed up at age 11 years. Following ICD-10 criteria 14 had been diagnosed within the autism spectrum (ASD), while 9 had been diagnosed with another developmental disorder (DD).
Baseline measures were observation in a semi-structured play interaction modelled after the PL-ADOS, the Mullen Scales of Early Developmet and clinical diagnosis.
Follow-up measures were the ADI-R, the Vineland Adaptive Behavior Scale – II, ADOS-G, either a short form of WISC-III, a short form of WPPSI-R or Mullen Scales of Early Development and clinical diagnosis.
Both groups show a significant increase in cognitive abilities during the follow-up period. The ASD group shows lower cognitive scores, higher degree of autistic symptoms in social interactions and communication, and a comparable level of adaptive functioning. Cross-time correlations are found for cognitive measures and measures of symptom severity. General adaptive level is best predicted by early scores of verbal IQ.
The follow-up of children referred with a suspicion of ASD shows a positive development in cognitive abilities but continuing difficulties with social interaction, communication and adaptive behaviour. The individual differences in outcome are associated with differences in early measures of cognitive abilities and symptom severity.