Autism is a complex disorder that typically appears during the first two years of life. It is one of the 3 autism spectrum disorders (ASD), along with Asperger syndrome and Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS). It is called a “spectrum” disorder because people with ASD all have similar symptoms in 3 main areas of impairment, but when and how and what the symptoms are in each autistic individual can be very different.

1. Social Interaction
2. Communication
3. Restricted, repetitive behaviors

Three main areas of impairment in individuals within the Autism Spectrum

The current official diagnostic criteria for autism is the DSM-IV-TR, published by the American Psychiatric Association, can be found here. Please note a child does not have to show all of the items listed in order to receive the diagnosis. However, he/she must have at least 6 symptoms (including at least 2 from impairment in social interaction, 1 from communication , and 1 from restricted, repetitive behaviors).

Prevalence

The US government has reported in October 2008 that 1 in 100 American children has ASD, revising its 2007 estimate of 1 in 150 children. ASD has been more common in boys than in girls, with a 4:1 ratio.

Causes

We do not know what exactly causes ASD. Current theories have pointed to genetics, brain abnormality, immunization shots and others to be the likely candidates. Please check out our “What’s the Latest?” for the latest research on the causes of ASD.

Sources

American Psychiatric Association (2000). “Diagnostic criteria for 299.00 Autistic Disorder“. Diagnostic and Statistical Manual of Mental Disorders (4th, text revision (DSM-IV-TR) ed.). ISBN 0890420254.

Wallis, Claudia, (2009, Oct 5). New studies see a higher rate of autism: is the jump real?. Time.com. Retrieved from http://www.time.com/time/health/article/0,8599,1927824,00.html