Intellectual Disability (ID)
Intellectual disability (ID) is below-average cognitive ability with significant limitations
in adaptive skills areas.
The diagnosis of ID is made based on testing of cognitive and adaptive skills. Cognitive
skills are things like memory, reasoning, and learning. Adaptive skills are those
skills needed in daily live, such as self-care, home living, social skills, leisure
skills, health and safety, community participation and employment. In order to have
a diagnosis of ID, a child must have below-average cognitive ability (usually defined
as an Intelligence Quotient (IQ) of below 70), along with below-average adaptive
skills. These deficits must be present before age 18. Because intelligence testing
is not reliable in young children, young children often are not diagnosed with ID
before school age. Children often first are noted to have developmental delays in
language, motor, social, adaptive, or cognitive areas. These children may catch up,
may go on to have ID, or may not meet criteria for ID but instead have a domain specific
disorder (communication disorder or motor skills disorder).
How Many People Have Intellectual Disability?
Somewhere between 1 and 3 of every 100 Americans have ID.
What Causes Intellectual Disability?
ID can be caused by any condition that impairs development of the brain before birth,
during birth, or during the early childhood years. In about 1 of 3 of people with
intellectual disabilities, the cause is unknown. The most common known causes of
intellectual disabilities are fetal alcohol spectrum disorder (FASD) and genetic
conditions including Down syndrome and ID syndrome.
Associated Developmental and Learning Issues
The impact of having an ID varies considerably, just as the range of abilities varies
considerably among all people. Children may take longer to learn to speak, walk and
take care of their personal needs, such as dressing or eating. It may take longer
to learn in school. As adults, some people are able to lead independent lives in
the community, while others require more formal supports.
There is no cure for ID, but with treatment and supports, those with intellectual
disabilities can lead satisfying lives in the community.
Associated Health Conditions
For a variety of reasons, certain health conditions are more common in children
with intellectual disability. It is important that these are recognized and treated.
A child with ID who is physically healthy is more likely to do well in school and
in other treatments. This contributes to more independence, better daily functioning,
and better quality of life.
- Dysmenorrhea (painful menstruation)
- Feeding and growth problems
- GI problems (gastroesophageal reflux disease (GERD), constipation)
- Musculoskeletal problems including hypotonia and scoliosis
- Oral health problems
- Otitis Media (ear infections)
- Sleep problems
- Vision and hearing problems
Associated Behavioral Conditions
Some, but not all, children with ID have behavioral challenges such as
- Aggression, self-injury