"What's the difference between Asperger's Syndrome and High-Functioning Autism?"
The short answer is: "very little, if any." And in the DSM-5, which comes out in May of 2013, Aspergers will be referred to as "High-Functioning Autism" (HFA).
Aspergers and HFA are currently considered separate diagnoses along the spectrum of autistic disorders. Even so, there are many similarities between the disorders so that some consider them to be different labels for the same condition.
Both those with Aspergers and HFA have difficulties with sensory functioning and can't tolerate certain noises or certain kinds of tactile stimuli. By definition, those with either disorder have an IQ which is at, near or above the normal intelligence range. Both conditions involve a child or adult who has learned to function in society or in their surroundings by relying on the skills they happen to be good at.
Children with Aspergers and HFA think better in visual terms. They see pictures in their heads when recalling something and don’t have a particularly good ability to think in words. Both diagnoses are associated with a relative inability to understand nonverbal cues and facial expressions.
The primary difference noted in the diagnostic criteria for each disorder is the finding of a greater speech delay in children with HFA when compared to those with Aspergers. Others feel this represents a continuum and that this shouldn’t be enough to establish one diagnosis over another. Albert Einstein, for example, was felt to have characteristics of Aspergers, yet he didn’t speak until he was three years old.
Unfortunately, there are no specific blood tests or other diagnostic tests to differentiate between the two diagnoses. Instead the diagnosis is based on clinical judgment and observation. Some children with tentative HFA will catch up on verbal skills and will carry the same diagnostic appearance that Aspergers individuals do. Their IQ may be at least as high as other children labeled with Aspergers.
Children with Aspergers and HFA are both high functioning and, in general, they can all read, write, speak and understand. In the end, the final subtleties between the two diagnoses may just be a matter of semantics and may not represent a true difference in diagnoses. And, as stated earlier, an Aspergers diagnosis will be an HFA diagnosis starting next year.