What’s with the rapid rise in autism?
Posted on April 22nd, 2008 by Lisa
Is the rise in autism due to better diagnosis? Heightened awareness? Or is there a genuine increase in incidence? As a Speech-Language Pathologist, I’m often asked those sort of questions. When we don’t know what causes autism, these can be difficult questions to answer. So it was good to read a press release about an expert doing new research on the rise in the incidence of autism.
The press release reports that Professor Dorothy Bishop, a Welcome Trust Principal Research Fellow at the University of Oxford, led a study revisiting 38 adults who had been diagnosed with developmental language disorders as children. These adults are now between the ages of 15 and 31, and none of them had been given an autism diagnosis.
Professor Bishop and colleagues looked at whether they now met current diagnostic criteria for autistic spectrum disorders — either through reports of their childhood behavior or on the basis of their current behavior.
These were children that people were saying were not autistic in the 1980s, but when we talk to their parents now about what they were like as children, it’s clear that they would be classified as autistic now. Criteria for diagnosing autism were much more stringent in the 1980s than nowadays and a child wouldn’t be classed as autistic unless he or she was very severe. Now, children are being identified who have more subtle characteristics and who could in the past easily have been missed.
Professor Bishop cautions against using the results to suggest that the prevalence of autism is not genuinely rising. She states:
We can’t say that genuine cases of autism are not on the increase as the numbers in our study are very small. However, this is the only study to date where direct evidence has been found of people who would have had a different diagnosis today than they were given fifteen or twenty years ago.
Results will be published this month in the Journal of Developmental Medicine & Child Neurology.