Children with autism spectrum disorders (ASDs) have a wide trajectory of developmental outcome. It is especially difficult to determine long term outcome in children under 3 years of age. For children over age 3 years the absence of expressive language, global cognitive delays and a disinterest in social interaction are highly suggestive of long term problems. As a general rule early identification and service provision associated with educational and community inclusion are the most important factors effecting long term adaptive behavior.
Many children with mild forms of ASDs including those in the past diagnosed as having Pervasive Developmental Disorders not otherwise specified (NOS) and high functioning (HF) Asperger Syndrome (AS) have positive outcomes and develop abilities that allow integrated functioning in school and workplace settings. The majority of these children, however, continue to display residual signs of social awkwardness, restricted interests and repetitive behaviors and activities.
More impaired outcomes are seen for children with more extensive or severe intellectual disabilities, seizures, associated psychiatric or medical disorders and more severe signs and symptoms of ASD. These children have more difficulty adapting to their surroundings and learning. Those with normal intelligence and minimal autistic symptoms have the greatest chance of transitioning successfully into the adult years.
Genetic prognostic information is difficult to provide due to the wide spectrum of diagnosis. When a broad inclusion is used for children with a diagnosis of an idiopathic ASD there may be a 20-30% risk of having a second child after the first child is diagnosed. If a second child is diagnosed then the risk may increase to 40-50% for the third child.