ASD Trajectories

Recent statistics have confirmed more children are being diagnosed as having an
autism spectrum disorder (ASD). The most recent prevalence estimates for children is 1 per 110 children aged 8 years. This has raised the visibility of ASDs for parents and the public in general. Due to this increased awareness many new questions are being asked. The biggest question concerns outcome. Parents and the general public want to know what are the developmental expectations for a child diagnosed with an ASD. This is a difficult question to answer due to the almost certain multiple causes of autism and the variability of presentation. In addition, the roles of genetic predisposition and environmental factors support the complexity of causation and presentation. Although information concerning developmental trajectory and prognostic forecasting is limited, there are certain patterns parents should be aware of.

A child’s development over time can be analyzed in terms of a series of time related skills. Following the patterns of skill acquisition allows a learning trajectory to be determined. When this is done for children with ASDs there is no single expected learning trajectory.  A range of trajectories has recently been reported for the major
symptom issues of communication, social skills and repetitive behaviors (Pediatrics, April 2,2012).

The patterns fell into various categories. The categories ranged from low to high functioning (HF). In general from birth through age 14 years patterns of functioning improved most for children who were high functioning and less for those who were low functioning. Children with high functioning scores tend to improve most over time.  Repetitive behaviors remained flat for all the ranges except for a small set of children (7%) who showed a decrease in functioning and another small set (8%) who showed improvement. There was a subset of children, however, called “bloomers.” Bloomers initially resemble low functioning children with ASD but over time they change and resemble high functioning children with ASD. The percentage of children in the sample staudied ranged from 7.5-10.7%.

This information is important for parents. Although studies spanning extended life periods are limited many clinicians have recognized a small percentage of children who initially begin in the low functioning range do, in fact, substatially improve and perform in the high functioning range by mid adolesence. Children who do bloom are those without intellectual disablity and those with more educated, non-minority mothers. The factors that relate to this are unknown. Possible causes include positive environmental diversity and the quality and quantity of interventions.

As a parent what can you learn from this? Although these findings need to be confirmed by future data reviews and modeling the information does support the diversity of ASD
presentation; the general improvement in communication and social skills over
time; the relative lack of change in repetitive behaviors  over time with the
exception of one group that improved and 1 group that worsened;  and the
presence of a group of children (“bloomers”0 diagnosed as having an ASD who
initially are in the low functioning category and dramatically improved to the high functioning level as they aged to age 14 years.

This study provides helpful prognostic advice to set and understand expectations for a child with an ASD.