The symptoms of autism spectrum disorders in adolescence and adulthood.

Seltzer MM, Krauss MW, Shattuck PT, Orsmond G, Swe A, Lord C.

Journal of Autism and Developmental Disorders 2003; 33(6): 565-581.

Background: There has been very little written about the life course of people with autism. Most literature is concerned with young children, but it is important to understand the way in which children with autism can be expected to develop through life. This study looks at a fairly large group of adolescents and adults and assesses how their symptoms of autism changed as they got older.

Question: Do autistic symptoms change during adolescence and adulthood amongst those whose diagnosis of ASD was made during childhood?

Design: Cross-sectional study.

Setting: The study was conducted in the American states of Wisconsin and Massachusetts.

Participants: 405 people with a diagnosis of an autism spectrum disorder between the ages of 10 and 53 years. The participants were divided into two age groups, 10 to 21, and 22 to 53 years of age. All had met the study criteria of having received a diagnosis of an ASD (autistic disorder, Asperger's Disorder, or PDD-NOS) from a professional and having ADI-R scores that match their diagnosis. People with Rett's Disorder, Childhood Disintegrative Disorder, tuberous sclerosis, or Fragile X syndrome were not included in the study. 73.1% of the participants were male and their average age was 21.74 years.

Assessment of prognostic factors: The ADI-R domains of communication, reciprocal social interaction, and restricted, repetitive behaviours and interests were scored.

Main Outcome Measures: Each participant received a score reflecting "current" level of impairment. They also received a "lifetime" score based on whether a symptom had been present at age 4-5 or at any time in their life, as reported by their mother. The items that made up the "lifetime" score showed a lack of social interaction for its own sake, rather than to benefit oneself (e.g., shared enjoyment as compared to requesting behaviour). The "current" score reflected the presence of abnormal behaviours.

Main Results: The communication and restricted, repetitive behaviours areas continued to present problems for individuals with autism throughout the lifespan. For the reciprocal social interaction domain, there were fewer adolescents than adults who currently had severe enough symptoms to warrant a diagnosis of autism. The adolescents were less impaired than the adults in the domain of reciprocal social interaction, but were more affected in relation to the restricted repetitive behaviours and interests. About 20% of all those who had moderate to severe symptoms in each domain during their lifetime were reported to be without symptoms during adolescence or adulthood.

Conclusions: This study raises valuable points about the life course of people with autism. The finding that the severity of symptoms decreased and in some cases disappeared is particularly interesting. The study has many strengths, particularly the number of subjects taking part and the fact that participants were individuals living in the community rather than individuals being seen at a clinic. The difference between the two groups could be related to the severity of symptoms. The study also looked at areas of life experience of adolescents and adults with autism that are usually neglected.

This study should be viewed somewhat cautiously as there were many factors that influenced its findings. Over the years, diagnostic methods have changed, there has been much improvement in treatment, and there are probably considerable developmental changes that take place during the years. The mothers' possibly inaccurate recall of behaviour that occurred many years ago could also influence the results. This study points up the need for continued research in this area.