Researchers from Columbia University, in a study published in the current Journal of Health & Place, identified an area including West Hollywood, Beverly Hills and some less posh neighborhoods that accounted for 3% of the state's new cases of autism every year from 1993 to 2001, even though it had only 1% of the population.
Another recent study, from the University of California, Davis, published in Autism Research, also found high rates of autism in children born around Los Angeles, as well as nine other California locations. Autism, usually diagnosed before a child is 3 years old, is a developmental disorder characterized by impaired social interaction and communication and repetitive behavior.
Both of the California-based studies suggest that local environmental or social factors are driving the high autism-diagnosis rates. And they conclude that childhood vaccinations—which some people fear is a factor behind rising autism—are not to blame. Otherwise, diagnoses of the disorder would be more evenly dispersed, they say.
The studies also disagree on some points. According to the UC Davis study, greater concentrations of autism occur in communities where parents are highly educated, which could mean they have more awareness of autism and access to treatment. By contrast, the Columbia researchers discount the role of educational levels. They believe that social influences, such as shared information about diagnoses, doctors and services, are largely responsible for the high rates they found in parts of Los Angeles.
A few weeks ago, NIMH posted an interview with Peter Bearman, the lead investigator for the Columbia study:
