Intellectual disability is often poorly understood because its effects vary greatly among those who have it. Many people with intellectual disability are mildly affected and may not be identified until later during school years. Individuals with intellectual disability may also have physical, medical, behavioral, psychological, or emotional problems.
People with intellectual disability who have a very low intelligence quotient (IQ) have serious limitations in their ability to function. However, with early intervention and appropriate support, they can also lead satisfying lives. The goal of treating intellectual disability is to help children stay in the family and take part in community life. In the United States, they are guaranteed education and other services.
Intellectual disability usually begins in childhood and is characterized by limitations in both intelligence and adaptive skills. The following 3 criteria must be met for a diagnosis of intellectual disability:
Any condition that impairs development of the brain before birth, during birth, or during childhood can cause intellectual disability. The main causes can be categorized as follows:
Genetic abnormalities may be inherited from parents or may be caused by environmental factors. There are many genetic diseases are associated with intellectual disability. Examples include:
Prematurity and low birth weight may sometimes lead to intellectual disability. Other birth complications and conditions or physical stress in the newborn stage may also injure an infant's brain.
Other conditions that can damage a child's brain and possibly lead to intellectual disability include:
The American Association on Intellectual and Developmental Disabilities (AAIDD) has a process for diagnosing and classifying a person with intellectual disability. This process involves assessing the person's IQ and adaptive skills. Adaptive skills fall into 3 categories:
The best assistance for people with intellectual disability begins with diagnosis and help early in life. Treatment includes:
With enough education and support, many people with intellectual disability can learn to take care of their basic needs and to live in the community.
Newborn screening followed by proper treatment can prevent intellectual disability resulting from certain conditions. Examples include:
Vaccines can prevent certain infectious diseases that may lead to intellectual disability. Women who plan to become pregnant should be current on all recommended vaccinations, such as:
Other interventions that can reduce the risk of intellectual disability include:
Many parents also choose to have certain tests done during pregnancy, including ultrasound, amniocentesis, chorionic villus sampling, and blood tests. These tests cannot prevent intellectual disability, but they can give parents more time to prepare for a child with intellectual disability.
American Association on Intellectual and Developmental Disabilities
Centers for Disease Control and Prevention
Intellectual disability. The ARC website. Available at: http://www.thearc.org/page.aspx?pid=2543. Accessed July 19, 2016.
Children with an intellectual disability. The American Academy of Child and Adolescent Psychiatry website. Available at: http://www.aacap.org/aacap/Families_and_Youth/Facts_for_Families/Facts_for_Families_Pages/Children_with_an_Intellectual_Disability_23.aspx. Updated October 2013. Accessed July 19, 2016.
Diagnostic adaptive behavior scale. American Association on Intellectual and Developmental Disabilities website. Available at: http://aaidd.org/intellectual-disability/diagnostic-adaptive-behavior-scale. Accessed July 19, 2016.
Free appropriate public education for students with disabilities. US Department of Education website. Available at: http://www2.ed.gov/about/offices/list/ocr/docs/edlite-FAPE504.html. Updated August 2010. Accessed July 19, 2016.
Intellectual disability. National Dissemination Center for Children With Disabilities website. Available at: http://nichcy.org/disability/specific/intellectual. Updated July 2015. Accessed July 19, 2016.
Intellectual disability. Merck Manual Professional Version website. Available at: https://www.merckmanuals.com/professional/pediatrics/learning-and-developmental-disorders/intellectual-disability. Updated February 2016. Accessed July 19, 2016.
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Last reviewed July 2016 by Michael Woods, MD Last Updated: 10/3/2014