- What is autism spectrum disorder (ASD)?
- What are the symptoms of ASD?
- How is ASD diagnosed?
- What are some other conditions that children with ASD may have?
- How is ASD treated?
- How common is ASD?
- What causes ASD?
- What efforts are under way to improve the detection and treatment of ASD?
- How can I help a child who has ASD?
- For More Information on Autism Spectrum Disorder
How common is ASD?
Studies measuring autism spectrum disorder (ASD) prevalence—the number of children affected by ASD over a given time period—have reported varying results, depending on when and where the studies were conducted and how the studies defined ASD.
In a 2009 government survey on ASD prevalence, the Centers for Disease Control and Prevention (CDC) found that the rate of ASD was higher than in past U.S. studies. Based on health and school records of 8-year-olds in 14 communities throughout the country, the CDC survey found that around 1 in 110 children has ASD.41 Boys face about four to five times higher risk than girls.
Experts disagree about whether this shows a true increase in ASD prevalence. Since the earlier studies were completed, guidelines for diagnosis have changed. Also, many more parents and doctors now know about ASD, so parents are more likely to take their children to be diagnosed, and more doctors are able to properly diagnose ASD. These and other changes may help explain some differences in prevalence numbers. Even so, the CDC report confirms other recent studies showing that more children are being diagnosed with ASD than ever before. For more information, please visit the autism section of the CDC websiteExternal Link: Please review our disclaimer..