So what is considered mild autism? As the word mild implies, it means there's a "little bit" of autism, per say. So what does that mean? On a gradient, when a child has symptoms, we look at the core symptoms of speech and language delay for example, or difficulty with social referencing and social engagement, social communication and, again, the restricted repertoire of play and repetitive behaviors. So if a child has a little bit of speech delay or some difficulty with speech and language, or a little bit of echolalia or some difficulty with social engagement, or has some repetitive stereotypic behaviors and play which can be redirected easily, you are hitting criteria of autism but the involvement is mild. With the new DSM-IV diagnosis, they actually want you to look at levels of severity. A lot of schools do the CARS, which is the Child Autism Rating Scale and they do have differentiation of mild, moderate, and severe. Mild would really come in that category when you look at symptoms and their severity. Based on that, you can actually say mild autism.
To clarify, the diagnosis of Pervasive Developmental Disorder, not otherwise specified, was often used for kids with what we now say, mild autism. Because they have just a few of the symptoms, they don't classically hit all of the autism criteria, but they have some of these differences that parents can say, for example: covering their ears, or sensitive to sounds, or not picking up in social relationships, not picking up cues, having difficulty understanding jokes, for example, being very literal or what they call poor pragmatics, or having particular fascinations-everything is Thomas the Tank engine. They can be transitioned, but they have particular tendencies which is different from another neurotypically developing child.
A lot of these children do get diagnosed with PDD, not otherwise specified, or mild autism and it's really a matter of degree. I think the important thing is to get formalized testing done so you really know where your child falls in the spectrum, and you have a sense of how impaired your child is, or how little impaired your child is, and then you can compare your child to her or himself so that they'll be measured along their own spectrum, not just with a reference to other children.