So what do we mean by an autism spectrum disorder? Spectrum, the word, basically means range. That is what we are seeing with these children that the three areas, the core symptoms of social engagement, speech and language communication, and restricted patterns of behavior and play. This can vary, and it's the degree to which the child has these symptoms is why we call it an autism spectrum. It's like when does a difference become a dysfunction, become a disorder, so it's really a matter of degree. I think we need to describe each child individually. You can have a child who's absolutely, for example, like an Asperger's. They have normal speech and language communication. They're not delayed. They may have difficulty with pragmatics, or staying on topic or be concrete, but they are not delayed with speech and language. Their IQ is actually within normal, but they can have certain particular interests and fascinations, or have some sensory issues, and motor coordination issues. That would be Asperger's, and that also comes within the spectrum of autism.
On the other hand, you have a child who is completely mute and non-verbal has no eye contact and spinning as if in their own world and very avoidant to touch. That is another extreme of what probably Dr. Kanner called classic autism. The new definition, where this term autism spectrum disorders has been used is really with the DSM-IV that has come into effect as of May 2013. I think we've always used that term, and it's a way of describing the child even within their own range. You can have a child who's more severely impacted, to a child who actually the symptoms get milder, so you've improved along the spectrum. There are psychological tests that you can do, for example, something like the CARS, which gives you numbers of mild, moderate, or severe. Sometimes parents like that and need that. It's often done in the school system to monitor progression and symptoms.
The spectrum, I think, also includes what we call the autism phenotype. There are people who just have some of the symptoms without hitting all the classic symptoms of autism and that was previously, or still called, Pervasive Developmental Delay, PDD, not otherwise specified. That is a commonly used term. It's like depression, not otherwise specified. Parents get confused by that, but it's like saying "You have some of the symptoms, or your child has some of these symptoms" without hitting all the symptoms, or all the criteria. Since this is a criteria based diagnosis, it's important that we put it in this kind of definition. The fact that children actually move along the spectrum helps us understand what is helping them and what is actually making their symptoms worse.