BRIEFS

The last issue of the Journal of Autism and Developmental Disorders included one of the largest examinations of the association between maternal infection during pregnancy and risk for autism. The study was conducted in the Denmark where researchers examined the maternal infection rates during pregnancy and autism diagnoses for all children born in Denmark between 1980 and 2005. ASD diagnosis was calculated by examining the Danish Psychiatric Central Registry, which includes information of all children who received outpatient or inpatient treatment with a diagnosis of ASD during those years. The researchers also examined the Danish National Hospital Registry, which includes information about all hospital admissions in the entire country during that time. Read More

I should start this new post by explaining why I’ve been mostly absent for the last month. September was an interesting and challenging month. I could say it was a perfect storm, combining the start of the academic year, preparing a new graduate seminar I had never taught before, transitioning into my new role as Assistant Professor at the University of Michigan, and rushing to get my new research laboratory functioning. Fortunately however, things are finally settling down and I can start to catch up with the child psych literature. I hope from now on I will be able to write a new post every Monday morning.

I thought it would be appropriate to start the month with some thoughts about the new Autism prevalence study that was just published in Pediatrics and which hit the news cycle this morning.

In sum, the study found that the prevalence of parent-reported rates of autism was higher than previous estimates. Specifically, they found that 1.1% of all children aged 3 to 17 had autism (1 in 91) as compared to previous estimates of approximately 1 in 150.

Does this suggest an increase in autism rates between 2003 and 2007? Maybe, in that the finding is consistent with the possibility that autism rates are increasing. However, there are a number of issues that must be taken into account, especially the methodological differences between this study and the CDC study that reported prevalence rates for 2002.

For a more detailed explanation of the CDC report from where the 1 in 150 rate comes from read my previous post on the topic: Autism rates in the USA: where did the 1 in 150 number came from? Read More

Diagnostic Substitution is one of the factors that have been proposed as a cause, or at least a contributing source, of the dramatic increases in autism observed during the last 10-15 years. The basic idea behind diagnostic substitution is that children that today receive a diagnosis of Autism, would have received a different diagnosis 20 years ago. Thus, the theory would suggest that there has not been an actual increase in the number of children affected, but instead simply a shift in the way conditions are classified.

Evidence for and against diagnostic substitution continue to accumulate. For example, last year I commented on a study showing that some adults that were diagnosed with pragmatic language impairment during their childhood actually meet diagnostic criteria for autism. But in an upcoming issue of the Journal of Autism and Developmental Disabilities, researchers from the California Department of Public Health report the findings of an examination in diagnostic coding practices in California during the past 20 years. Read More