Stability and change among high-functioning children with pervasive developmental disorders: A 2-year outcome study.

Starr E, Szatmari P, Bryson S, Zwaigenbaum L.

Journal of Autism and Developmental Disorders, 33(1) February 2003

Bottom Line

Over a two-year time period did differences or similarities in symptoms between children with autism or Asperger syndrome become more apparent?

  • Communication symptoms decreased in both groups over time. Children with Asperger syndrome had fewer symptoms compared to children with autism.
  • Repetitive activities or stimming (e.g., rocking or hand flapping) were more likely in children with autism, but this symptom did not change over time for either group.
  • Social reciprocity or the ability to engage in give-and-take interactions with other people worsened for both groups over time, but the children with Asperger syndrome had more severe problems.
  • Children with autism and Asperger syndrome need knowledge and skills to cope with social situations so that they do not feel rejected or become victims of bullying.

Question: What is the 2-year outcome on the Autism Diagnostic Interview of a group of children diagnosed with autism or Asperger Syndrome?

Background: Many researchers and clinicians question whether there is a meaningful distinction between children who have been given the diagnosis of autism and those who have been diagnosed as having Asperger syndrome. Determining if there is dissimilarity in the outcome for children with these conditions may provide a means of differentiating them or showing that they are one and the same condition.

One of the ways that the natural history or the outcome of medical conditions can be determined is through long-term studies. Research in which children are followed over time and periodically are tested is called a time series study.

Design: Time series, a study design in which people are followed over time and on whom periodic testing is done.

Setting: Southern Ontario, Canada

Participants: Sixty-four 6- to 8-year-old children from a long-term follow-up study, selected on the basis of having an IQ of at least 70 and a diagnosis of autism or Asperger syndrome.

Assessment of Prognostic Factors: An abbreviated version of the Autism Diagnostic Interview (ADI) focusing on the portions dealing with communication, play and social development, and repetitive or stereotyped behaviour was administered.

Main Outcome Measures: Change over time in ADI items dealing with communication, play and social development, repetitive or stereotyped interests. Differences between children with a diagnosis of autism or of Asperger syndrome

Main Results:

Communication: Autistic symptoms decreased with time in both groups. Children with Asperger syndrome showed fewer symptoms compared to children with autism. Over time the differences between the two groups diminished. The differences were likely due to the nature of the testing, which could only measure the lowest level of language dysfunction and therefore could not demonstrate any improvement in the Asperger group.

Repetitive activities: children with autism fared worse on testing than children with Asperger Syndrome, but there was no change over time for either group.

Social reciprocity: Time made a significant difference in this area. Symptoms worsened for children in both groups, but the scores for children with Asperger syndrome worsened over time to a greater degree than they did for children with autism. IQ did not explain the differences between the two groups.

Conclusions: Overall, children with both autism and Asperger syndrome showed an increase in symptoms related to social interaction, but the severity of those symptoms increased over time only in children with Asperger syndrome.

Compared to children with autism, children with Asperger syndrome had fewer symptoms in all three domains, but had increased symptom severity in the realms related to social interaction. It may be that children with Asperger syndrome, because of their generally higher level of communications skills, are more aware of the social demands placed upon them, thus making their difficulties in this realm more obvious.

Children need to be given greater knowledge and skills to cope with social demands and thus reduce the emotional toll taken on them from perceived or real rejection or victimization.