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Curated and updated for the community by APA
Intellectual disability involves problems with general mental abilities that affect functioning in two areas:
Intellectual disability affects about one percent of the population, and of those about 85 percent have mild intellectual disability.
See definition, symptoms, & treatment
United Cerebral Palsy (UCP)
ARC for People with Intellectual and Developmental Disabilities
I have heard the terms intellectual disability and developmental disability. Are they the same?
These terms are not the same, though there is some overlap. Developmental disability is a broad category that includes intellectual disability (ID) as well as autism spectrum disorder and other developmental diagnoses. Intellectual disability refers to people whose cognitive ability and adaptive functioning are significantly below average. People with autism spectrum disorder have difficulties with social interaction and impairments in communication; many also have intellectual disability. Read More
At what age can a child be evaluated for intellectual disability?
Parents and caretakers are often the first to notice delays in a child’s development.
If you’re concerned about the development of your infant or toddler, or you suspect your child has a disability, talk with your child’s pediatrician. You may also contact your local early Intervention program directly (see links below) and ask to have your child evaluated. Early intervention is a national system of services that helps babies and toddlers (birth to 3 years) with developmental delays or disabilities. Evaluation is provided free of charge.
See contact information for state early intervention programs. Learn more about early intervention from the Center for Parent Information and Resources. Read More
What is involved in diagnosing intellectual disability?
Intellectual disability involves problems in both intellectual and adaptive functioning.
Intellectual functioning is assessed with an exam by a doctor and through standardized testing. While a specific full-scale IQ test score is no longer required for diagnosis, standardized testing is used as part of diagnosing intellectual disability. A full scale IQ score of around 70 to 75 indicates a significant limitation in intellectual functioning. However, the IQ score must be considered in relation to the bigger picture of the person’s general mental abilities. Also, specific areas of intellectual functioning (identified in IQ subtest scores) can vary a great deal. So the full scale IQ score may not accurately reflect overall intellectual functioning.
Adaptive functioning refers to a child’s abilities with common skills needed for everyday life compared to other children the same age. Three areas of adaptive functioning are considered: conceptual (such as language and academic skills); social (such as communication skills and the ability to follow rules); and practical (such as personal care and other daily life skills). Adaptive functioning is assessed through standardized measures (questionnaires/checklists) with the individual and through interviews with family members, teachers and caregivers. Read More
About the Expert:
Mark J. Hauser, M.D. Psychiatrist practicing in the Greater Boston Area President, On-Site Psychiatric Services, Inc.
Jordan, 32, loves his work. He lives with and assists his aging grandparents. He is able to help them with cooking, cleaning, and exercising daily. Jordan has been very successful at helping his grandparents live independently by maintaining the basic chores of their home and keeping a structured environment for them. He describes himself as "a good helper."
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MAY 16, 2018
Since 2008, increased federal funding for these programs and the additionally enrolled or eligible people for either of the federal programs, have led to the growth of the residential intellectual disability facilities in the U.S. Although the demand for housing or residential facilities for people with intellectual disabilities has been increasing in the recent years, the adequate supply of such facilities has not kept the required pace.
MAY 14, 2018
Under federal law, students with disabilities are supposed to attend class with their typically-developing peers as much as possible, but new research suggests that may not be happening. In what researchers say is the first study to look at national trends in school placement for students with intellectual disabilities over the last four decades, they found that the majority of these children spent most or all of their time in self-contained settiings.
MAY 9, 2018
The current edition of the “Diagnostic and Statistical Manual of Mental Disorders,” or DSM-5, introduced a new term and definition for ‘mental retardation,’ renaming the condition ‘intellectual disability.’ Although the change took place five years ago, we still lack empirical findings to evaluate its reliability, validity and impact.
Physician Reviewed
Ranna Parekh, M.D., M.P.H. November 2015