Autism and developmental profiles in preschoolers: stability and change over time

Increasing numbers of young children are now being diagnosed with autism spectrum disorder (ASD). This study aimed to analyse developmental trajectories in a representative group of preschool children with ASD.

In a naturalistic study, 208 preschool children with different subtypes of ASD were followed over a 2-year period. Their trajectories, as regards persistence of ASD diagnoses, developmental/intellectual levels, adaptive functioning and expressive speech, were monitored.

Developmental profiles showed considerable change over time, especially in children with atypical autism and in those with developmental delay/borderline intellectual functioning at their first assessment. Approximately 50% of the children were found to have intellectual disability (ID) at follow-up and, of these, the majority had severe ID. This was in contrast to the first assessment by the referral team when ID had rarely been mentioned or discussed.

Changes in developmental profiles during preschool years are common in children with ASD. This implies that reassessments, covering different developmental areas, are needed. Such follow-up assessments prior to the start of school will yield a more valid estimation of the child's general cognitive level and a more accurate ASD diagnosis and thus form a better basis for realistic educational planning and intervention.