This article comes from a subscriber’s question about ADHD and Autism.
The question is: “what is the prevalence rate of ADHD when the child has been diagnosed with Autism?”
This is a very good question. In fact this is a question that led me to do a lot of homework. I pulled out the textbooks, I pulled out notebooks from conferences I’ve been to. I pulled out journals, I searched online etc. and I finally have an answer for you. It was a very smart question.
First of all I need to go back to the DSM which as you will recall is the Diagnostic and Statistic Manual of the American Psychiatric Association that has the diagnostic criteria for the psychiatric disorders.
In the diagnostic criteria for ADHD which is covered in a previous article, there are exclusionary criteria.
Criterion E is ‘the symptoms do not occur exclusively during the course of a pervasive developmental disorder, schizophrenia or other psychotic disorder etc.”
Now for those of you who are not aware a Pervasive Developmental Disorder (PDD) is another term for autism or another disorder on the autistic spectrum (such as Asperger’s Disorder).
Thus, by strict interpretation of the DSM-IV-TR criteria, when someone has a diagnosis of Autism or a Pervasive Developmental Disorder, then they technically shouldn’t be diagnosed with ADHD.
Coming back to the question: ‘what’s the prevalence rate of ADHD when the child has been diagnosed with autism?’
According to the DSM-IV-TR, it is zero, because it is not possible.
Now the reason why I spent so much time looking for the answer is because I see it in my office a lot; kids who have Autistic Spectrum Disorders (another term for PDD, Autism or Asperger’s) and seem to have ADHD type symptoms and benefit from ADHD treatments.
I was able to find somewhat of an answer in an article published by Goldstein and Schwayback in the Journal of Autism and Developmental Disorders published in June 2005.
In that article they looked at 57 kids with an Autistic Spectrum Disorder and they reviewed all of the data available in what was called a retrospective chart review - that’s looking back at children that had already been assessed. They found that they had sufficient data in 27 children to see whether they actually had ADHD symptoms to the level that they could meet a diagnosis for ADHD. Of the 27, 7 of them or 26 % met enough criteria to reach a diagnosis of ADHD combined type. Nine of them or 33% had enough criteria to meet the ADHD inattentive type and 11 of them or 41% didn’t have any ADHD type symptoms.
In this very small sample, what I would call a preliminary study, about 26% of these Autistic kids had ADHD combined type and 33% had ADHD inattentive type; 41% didn’t have ADHD at all.
Now as I said this is a very preliminary study and it’s not conclusive at all and certainly a lot more needs to be done.
I will tell you that in my clinical practice I do see kids with Autistic Spectrum Disorders who do have symptoms of ADHD, or meet the full diagnostic criteria.
Perhaps I should have prefaced this article with the fact that I can’t do a comprehensive review of Autism in this article. Frankly, a whole blog can be written about autism because of its complexity and the struggles that families have in dealing with children (and teens and adults) with Autism. For an overview, please visit this article on Autism and Asperger’s.
So coming back to our question I guess we can say that according to a preliminary study 26% of kids with autism had ADHD combined type and 33% had ADHD inattentive type suggesting about 50 to 60 percent of kids with autistic spectrum may have ADHD. As I say take this with a big grain of salt because it’s a preliminary study.
Share This