Autism
Key points
- Autism is a complex developmental disorder that appears in the first 3 years of life, although it is sometimes diagnosed much later.
- Autism is a physical condition linked to abnormal biology and neurochemistry in the brain.
- Most parents of autistic children suspect that something is wrong by the time the child is 18 months old and seek help by the time the child is 2.
- Routine developmental screening should be performed for all children at all well-child visits to their pediatrician.
Alternative names
Autistic disorder/Autism spectrum; Pervasive developmental delay
Definition
Autism is a complex developmental disorder that appears in the first 3 years of life, although it is sometimes diagnosed much later. It affects the brain's normal development of social and communication skills.
Autism is a spectrum that encompasses a wide range of behavior. The core features include impaired social interactions, impaired verbal and nonverbal communication, and restricted and repetitive patterns of behavior.
The symptoms may vary from quite mild to quite severe. A related, milder condition is Asperger's syndrome.
Causes, incidence, and risk factors
Autism is a physical condition linked to abnormal biology and neurochemistry in the brain. The exact causes of these abnormalities remain unknown, but this is a very active area of research. It is likely a combination of factors that leads to Autism.
Genetic factors seem to be important. For example, identical twins are much more likely than fraternal twins or siblings to both have Autism. Similarly, language abnormalities are more common in relatives of autistic children. Chromosomal abnormalities and other neurological problems are also more common in families with Autism.
Autism may also be linked to certain changes or abnormalities along the digestive tract. This has raised question about whether diet or other factors may play a role in the disease. For example, there is some question of whether eating certain foods like wheat and milk may worsen symptoms of Autism. The theory is that proteins in these foods (gluten in grains and casein in dairy products) may cause the gut to become leaky in children with Autism. The leakiness introduces certain substances into the brain, possibly contributing to the behavioral problems associated with Autism. Research testing this theory is underway.
The exact number of children with Autism is not known, but estimates suggest that roughly 1 in 1,000 children are affected. affects boys 3 to 4 times more often than girls. Family income, education, and lifestyle do not seem to affect the risk of .
Written and revised by
David Cohen, M.D.
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