There is considerable overlap among the different forms of autism. The wide variation in symptoms among children with autism, however, has led to the concept of autism spectrum disorder, or ASD.
ASDs affect one out of every 88 children in the U.S. They occur more often among boys than girls. While autism appears to be on the rise, it's unclear whether the growing number of diagnoses shows a real increase or comes from improved detection.
Although the cause of autism is not known, many researchers believe genetics is responsible for 90% of the risk of a child developing autism. Rare cases may be caused by chemical exposure and other agents that can cause birth defects.
To reduce the risk of having a child with an autistic disorder:
Do not take drugs during pregnancy unless your doctor approves; this is particularly true for some seizure medications.
Do not drink alcoholic beverages of any kind while you are pregnant.
Early diagnosis is important. That's because early treatment can help a child with autism make significant gains in language and social skills.
Signs of Autism Spectrum Disorder
Autism spectrum disorders affect three different areas of a child's life:
Communication -- both verbal and non verbal
Behaviors and interests
Each child with an ASD will have his or her own pattern of autism.
Sometimes, a child's development is delayed from birth. Some children seem to develop normally before they suddenly lose social or language skills. Others show normal development until they have enough language to demonstrate unusual thoughts and preoccupations.
In some children, a loss of language is the major impairment. In others, unusual behaviors (like spending hours lining up toys) seem to to be the dominant factors.
Parents are usually the first to notice something is wrong. But a diagnosis of autism is often delayed. Parents or a physician may downplay early signs of autism, suggesting the symptoms are "just a phase" or a sign of a minor delay in development. Children with a possible autism spectrum disorder, though, should be evaluated by a professional team with experience in diagnosing autism.
Until recently, the types of ASD have been determined by guidelines in the diagnostic manual (DSM - IV) of the American Psychiatric Association. According to the CDC, the three main types of ASD are:
Pervasive developmental disorder, not otherwise specified (PDD-NOS)
The DSM -IV also included two rare but severe autistic-like conditions -- Rett syndrome and childhood disintegrative disorder.
The new diagnostic manual has made some major changes in this list of disorders. It's unclear, though, how these changes will affect the way health professionals define exactly what is an autistic spectrum disorder.
The mildest form of autism, Asperger's syndrome (AS) affects boys three times more often than girls. Children with AS become obsessively interested in a single object or topic. They often learn all about their preferred subject and discuss it nonstop. Their social skills, however, are markedly impaired, and they are often awkward and uncoordinated.
Asperger's syndrome is mild compared to other ASDs. Also, children with AS frequently have normal to above average intelligence. As a result, some doctors call it "high-functioning autism." As children with AS enter adulthood, though, they are at high risk for anxiety and depression.