What is Autism? What's PDD-NOS? What's the difference?

There are so many ways to explain "Autism." Sam was originally diagnosed with PDD-NOS, and now has a diagnosis of Autism Spectrum Disorder. Here is the most "dummied down" version of an explaination I have found as of now. (Courtsey of WebMD) Hope this helps you to understand. I know it sure helped clear up this differences for me.


Autism Spectrum Disorders

The forms of autism are thought to overlap considerably. But the fact that there is wide variation in symptoms among children with autism led to the concept of autism spectrum disorder. Autism seems to be on the rise, and autism spectrum disorders affect between two and six children out of every 1,000 in the U.S. It's unclear, though, whether the growing incidence of autism represents a real increase or just improved detection. Early diagnosis of an autism spectrum disorder is important. That's because detection leads to treatment, and with early treatment, a child with autism can gain improved language and social skills.

Signs of Autism Spectrum Disorder

Autism spectrum disorders affect three different areas of a child's life:
social interaction
communication (nonverbal and/or verbal)
repetitive behaviors or interests

Each child with an autism spectrum disorder will have his or her own individual pattern of autism. Sometimes, a child's development is delayed from birth. Other children with autism develop normally before suddenly losing social or language skills. In some children, a loss of language is the impairment. In others, unusual behaviors (like spending hours lining up toys) predominate.

Parents are usually the first to notice something is wrong. However, the diagnosis of autism is often delayed. The parents or a physician often downplay early signs of autism. They may optimistically suggest "it's just a phase" or a trivial delay in development. Children with a suspected autism spectrum disorder should be evaluated by a professional team with experience in diagnosing autism.

There are three main forms of autism spectrum disorder, and two rare, severe autistic-like conditions:
Asperger's syndrome
pervasive developmental disorder, not otherwise specified ( PDD-NOS)
autistic disorder (Here's our Lily bug!)
Rett syndrome
childhood disintegrative disorder

Asperger's Syndrome
The mildest form of autism, Asperger's syndrome affects boys three times more often than girls. Children with Asperger's syndrome become obsessively interested in a single object or topic. They often learn all about their preferred subject, and discuss it nonstop. Their social skills are markedly impaired, though. They are often awkward and uncoordinated physically.
Because Asperger's syndrome is mild compared to other autism spectrum disorders, some doctors call it "high-functioning autism." As children with Asperger syndrome enter young adulthood, though, they are at high risk for anxiety and depression.

Pervasive Developmental Disorder, Not Otherwise Specified (PDD-NOS)
This mouthful of a diagnosis applies to most children with autistic spectrum disorder. Children whose autism is more severe than Asperger's syndrome but not as severe as autistic disorder are diagnosed with PDD-NOS. Autism symptoms in kids with PDD-NOS vary widely, making it hard to generalize. Overall, compared to children with other autistic spectrum disorders, children with PDD-NOS have: impairment in social interaction -- like all children with autistic spectrum disorder better language skills than kids with autistic disorder, but not as good as those with Asperger's syndrome fewer repetitive behaviors than children with Asperger's syndrome or autistic disorder a later age of onset However, no two children with PDD-NOS are exactly alike in their symptoms. In fact, there are no agreed-upon criteria for diagnosing PDD-NOS. In effect, if a child seems autistic to professional evaluators but doesn't meet all the criteria for autistic disorder, he or she has PDD-NOS.

Autistic Disorder
Children who meet more rigid criteria for diagnosis of autism have autistic disorder. They have more severe impairments involving social and language functioning, as well as repetitive behaviors. Often, they have mental retardation and seizures as well.

There are two rare, severe forms of autistic spectrum disorder that are considered separately from the others: Rett syndrome and childhood disintegrative disorder.

Rett Syndrome
Almost exclusively affecting girls, Rett syndrome is rare. About one in 10,000 to 15,000 girls develop this severe form of autism. Between 6 and 18 months of age, a little girl stops responding socially, wrings her hands habitually, and loses language skills. Coordination problems appear and can become severe. Rett syndrome is usually caused by a genetic mutation. The mutation usually occurs randomly, rather than being inherited. Treatment focuses on physical therapy and speech therapy to improve function.

Childhood Disintegrative Disorder
The most severe autistic spectrum disorder, childhood disintegrative disorder (CDD), is also the least common. After a period of normal development, usually between age 2 and 4, a child with CDD rapidly loses multiple areas of function. Social and language skills are lost, as well as intellectual abilities. Often, the child develops a seizure disorder. Children with childhood disintegrative disorder are severely impaired and don't recover their lost function.
Fewer than two children per 100,000 with an autistic spectrum disorder meet criteria for childhood disintegrative disorder. Boys are affected by CDD more often than girls.