Autism spectrum disorder (ASD) is a developmental disorder. It often appears in the first 3 years of life. ASD affects the brain's ability to develop normal social and communication skills.
Autism; Autistic disorder; Asperger syndrome; Childhood disintegrative disorder; Pervasive developmental disorder
The exact cause of ASD isn't known. It's likely a number of factors that lead to ASD. Research shows that genes may be involved since ASD runs in some families. Certain medicines taken during pregnancy may also lead to ASD in the child.
Other causes have been suspected, but not proven. Some scientists believe that damage to a part of the brain, called the amygdala, may be involved. Others are looking at whether a virus may trigger symptoms.
Some parents have heard that vaccines may cause ASD. But studies have found no link between vaccines and ASD. All expert medical and government groups state that there is no link between vaccines and ASD.
The increase in children with ASD may be due to better diagnosis and newer definitions of ASD. Autism spectrum disorder now includes syndromes that used to be regarded as separate disorders:
- Autistic disorder
- Asperger syndrome
- Childhood disintegrative disorder
- Pervasive developmental disorder