What Are Pervasive Developmental Disorders?
"Pervasive Developmental Disorder" is a formal term that means exactly the same thing as the less formal "autism spectrum disorder." As with the autism spectrum, the group of disorders described as pervasive developmental disorders includes autistic disorder, pervasive developmental disorder not otherwise specified (PDD-NOS), Asperger syndrome, Childhood Disintegrative Disorder and Rett Syndrome.What Is Asperger Syndrome?
Asperger syndrome describes individuals at the highest-functioning end of the autism spectrum. Unlike other autism spectrum disorders, Asperger syndrome is often diagnosed in teens and adults. People with Asperger syndrome generally develop spoken language in the same way as typically developing children, but have a tough time with social communication. These difficulties that become more obvious as they get older and social expectations rise. Because people with Asperger syndrome are often very intelligent - but "quirky" - the disorder is sometimes nicknamed "geek syndrome" or "little professor syndrome."What Is Mild Autism?
The term "mild autism" is not an official diagnosis. It's simply a more descriptive term than "Asperger syndrome" or "autism." Generally speaking, when people use the term mild autism they are referring to individuals whose symptoms fit an autism spectrum diagnosis, but who has strong verbal skills and few behavioral issues. Those individuals may, however, have significant problems with social communication. They may also have problems coping with too much sensory input (loud noise, bright lights, etc.).What Is High Functioning Autism?
Like "mild" autism, high functioning autism (sometimes shortened to HFA) is a made-up term that's become more and more commonly used. HFA is a tricky term, because it can be hard to distinguish a person with HFA from a person with Asperger syndrome. The official distinction is that people with HFA had or have speech delays, while people with Asperger Syndrome have normal speech development. But there may also be very real differences in terms of social awareness, personality characteristics, and other traits. The jury is still debating the fine distinctions.What Is Severe Autism (Autistic Disorder)?
Severe autism is officially termed autistic disorder. It goes by many other names, though, including profound autism, low functioning autism, or classic autism. People with autistic disorder are often non-verbal and intellectually disabled, and may have very challenging behaviors.What Is Rett Syndrome?
Rett syndrome is a genetic disorder that affects only girls. It is the only one of the autism spectrum disorders that can be diagnosed medically (so far). Girls with Rett syndrome develop severe symptoms including the hallmark social communication challenges of autism. In addition, Rett syndrome can profoundly impair girls' ability to use their hands usefully.reference
