National Institute of Child Health & Human Development
Autism and the MMR Vaccine

What is autism?

Autism is a complex biological disorder of development that lasts throughout a person’s life. People with autism have problems with social interaction and communication, so they may have trouble having a conversation with you, or they may not look you in the eye. They sometimes have behaviors that they have to do or that they do over and over, like not being able to listen until their pencils are lined up or saying the same sentence again and again. They may flap their arms to tell you they are happy, or they might hurt themselves to tell you they are not.

One person with autism may have different symptoms, show different behaviors, and come from different environments than others with autism.Because of these differences, doctors now think of autism as a “spectrum” disorder, or a group of disorders with a range of similar features. Doctors classify people with autism spectrum disorder (ASD) based on their autistic symptoms. A person with mild autistic symptoms is at one end of the spectrum. A person with more serious symptoms of autism is at the other end of the spectrum. But they both have a form of ASD.

The National Institute of Child Health and Human Development (NICHD), part of the National Institutes of Health (NIH), is one of the NIH Institutes doing research into various aspects of autism, including its causes, how many people have it, and its treatments.

NICHD
Last Update: 08/15/2006