Data released last week suggested an alarming rise in the prevalence of autism, with an estimated 1 in 88 children in the United States showing symptoms of the disorder — up from the previous estimate of 1 in 110. Until now, though, there’s been little information to help parents and physicians grasp the potential course a child’s disorder may take.
A study published Monday in the journal Pediatrics takes our understanding of autism far beyond the hard numbers by sketching out autism’s six common developmental trajectories.
Researchers at Columbia University analyzed data for about 7,000 children diagnosed with autism between 1992 and 2001. Those children, participants in a large California autism registry, had been evaluated for symptoms associated with autism yearly from the time of diagnosis through age 14. This study focused on changes in the children’s social and communication functions and the extent to which they engaged in the repetitive behaviors characteristic of autism.
The researchers found that while there was great variety among individual children’s symptoms, overall their development in those areas clustered into six distinct paths or trajectories.
For the most part, the trajectories of children’s repetitive behaviors showed little variation. But in the areas of social interaction and communication, some children developed quite quickly, while others progressed far more slowly, showing little appreciable improvement over the course of their childhoods and early adolescence.
About 10 percent of the children were deemed “bloomers,” moving rapidly from being severely affected by their autism symptoms to functioning at a high level. The research found that those children tended to have been born to highly educated, older, white mothers; they also tended to have been born on the later end of the study period (closer to 2001) than earlier (closer to 1992). Minority children, those whose families were on the low end of the socioeconomic scale and those born to less-educated mothers were far less likely to be “bloomers” or to achieve high-functioning status.
Children whose initial symptoms were least severe tended to improve more rapidly than those with more severe symptoms at the time of diagnosis. And children with intellectual disabilities generally progressed very slowly.
The study’s authors suggest that this glimpse into the way different children’s autism progresses may help us understand the condition better and to improve treatment options. In particular, they note, their work highlights the need to help those families in the lowest socioeconomic groups gain access to early intervention programs and other treatments that appear to have benefited those children who bloomed.