Autism and Intellectual Disability

Testing at ARUP Laboratories

About 1 percent of the general population is thought to have Intellectual Disability, and about 10% of individuals with Intellectual Disability have Autism Spectrum Disorder (ASD) or autistic traits. However, a much higher percentage of individuals with ASD have Intellectual Disability3.

The incidence of autism is 1 in 68 births in the United States. The occurrence is about 4.5 times more common in boys with a 1 in 42 incidence rate and girls have a rate of 1 in 1892.

About 1 in 6 children in the United States had a developmental disability in 2006-2008, ranging from mild disabilities such as speech and language impairments to serious developmental disabilities, such as intellectual disabilities, cerebral palsy, and autism2.

  • Autism spectrum disorder (ASD) is a developmental disability that can cause significant social, communication and behavioral challenges. The learning, thinking, and problem-solving abilities of people with ASD can range from gifted to severely challenged. Some people with ASD need a lot of help in their daily lives; others need less. A diagnosis of ASD now includes several conditions that used to be diagnosed separately: autistic disorder, pervasive developmental disorder not otherwise specified (PDD-NOS), and Asperger syndrome. These conditions are now all called autism spectrum disorder.
  • Intellectual disability is a disability characterized by significant limitations in both intellectual functioning and in adaptive behavior, which covers many everyday social and practical skills. This disability originates before the age of 18.