The Long-Term Course of Autism. Symptomatology and Social Adaptation Across the Life Span in a German Sample with Autism Spectrum Disorders

Background: Autism is known as a chronic condition associated with persistent deficits in social functioning and daily living skills. There is still a limited number of studies validating this concept and giving insight in the course of autism across the life span. A high variability in outcome has been shown in previous stuides. As prognostic factors cognitive and language abilities were replicated, but the relationship of severity and the pattern of autistic symptomatology on the later outcome remains still unclear. To our knowledge this is the first follow-up study assessing symptom patterns and social adaptation in a German sample.

Objectives: The aim of this study was to examine the outcome of participants with autism spectrum disorders in adolescence and adulthood with specific reference to social aspects (living conditions, education, employment) and the severity and patterns of the autism symptomatology. The identification of early characteristics predicting the social outcome of this condition is another relevant aim. 

Methods: The current clinical sample comprises 20 patients first diagnosed with an autism spectrum disorder between 1991 and 2006 in Frankfurt. The patients were followed a minimum of three years after diagnosis with a mean of 9,9 years (SD 4,34).  Mean age at follow up was 21,07 years (SD 6,19). Participants received a follow-up evaluation using the ADI and ADOS for diagnosis and as outcome parameters for severity of the autism symptomatology. The psychosocial outcome was measured using a sociodemographic interview assessing living conditions, educational success and employment at follow up. The social outcome among the partcipants was summarized using a classification similar to ratings published in previous studies ranging from good, fair, restricted to poor social outcome.  

Results: All participants met diagnostic criteria for autism spectrum disorders at follow-up. Parents report still a significant reduction in autism symptom severity in all domains from early childhood (assessed retrospectively for the age of 4-5 years) to the time of initial diagnosis. In the prospective examination with the ADOS the symptom patterns appear relatively stable from initial diagnosis to follow up. The social outcome in adolescence and adulthood is classified for about half of the participants as good to fair and for half of the participants as restricted to poor. As the strongest prognostic factor for social outcome cognitive abilities at age of diagnosis is replicated. No significant correlation was found between autism symptom severity at the time of diagnosis and later social outcome.

Conclusions: The preliminary findings confirm a very high diagnostic stability for autism spectrum disorders across the life span. A large proportion of the patients with autism spectrum disorders show a markedly improvement in symptom severity from preschool to school age, but show a relative high stability of symptom severity from adolescence to adulthood. The social outcome on the other hand is quite variable and is predicted even within the high-functioning-individuals by the cognitive abilities.