Intellectual Disability

(Cognitive Disability; Developmental Disability; Mental Retardation)

by Cynthia M. Johnson, MA

Definition

Intellectual disability is when a person has limits in:

Intellectual function—learning, reasoning, and problem solving
Adaptive behavior—daily tasks, such as communication and taking care of daily needs

Causes

The cause is not always known. The most common ones are:

Genetic problems, such as Down syndrome and Fragile X syndrome
Metabolic problems, such as phenylketonuria (PKU) and congenital hypothyroidism
Problems with brain development, such as hydrocephalus and malformation
Infections during pregnancy, such as toxoplasmosis, HIV, and rubella
Unhealthy habits during pregnancy, such as substance and alcohol use disorder
Problems at birth, such as being born very early or not getting enough oxygen
Problems during childhood, such as:
- Illnesses or infections that harm the brain, such as meningitis, encephalitis, and measles
- Head injury or near drowning
- Exposure to lead, mercury, and other toxins

Head Injury in Child

Risk Factors

This problem is more common in people who have other family members who have it. The risk is also higher in people who have any of the known causes.

Symptoms

Symptoms start before a child reaches age 18. Problems may be mild to severe. It varies from person to person.

Problems may be:

Learning and developing more slowly than other children of the same age
Problems communicating or socializing with others
Trouble learning in school
Problems doing everyday things like getting dressed or using the bathroom without help
Problems hearing, seeing, walking, or talking
Problems making decisions

Diagnosis

The doctor will ask about your child’s symptoms and health history. A physical exam will be done. Tests will be given to measure intellectual function and adaptive behavior.

Children with this problem have a higher risk for other disabilities. More tests may be done to look for these problems.

Treatment

There is no cure. The goal of treatment is to improve function and quality of life. This may allow some people to work and live on their own. Others may need support throughout their lives.

Treatment should be started early. Choices are:

Speech, physical, and occupational therapy
School-based services to help the child succeed in class
Job skills training

Prevention

Proper prenatal care may lower the risk of some causes.

RESOURCES:

The Arc
http://www.thearc.org

Kids Health—Nemours Foundation
http://kidshealth.org

CANADIAN RESOURCES:

Canadian Psychological Association
http://www.cpa.ca

Special Olympics Canada
http://www.specialolympics.ca

References:

Facts about intellectual disability. The Centers for Disease Control and Prevention website. Available at: https://www.cdc.gov/ncbddd/developmentaldisabilities/facts-about-intellectual-disability.html. Accessed January 27, 2021.

Intellectual disabilities in children—approach to the patient. EBSCO DynaMed website. Available at: https://www.dynamed.com/approach-to/intellectual-disabilities-in-children-approach-to-the-patient. Accessed January 27, 2021.

Purugganan O. Intellectual Disabilities. Pediatr Rev. 2018 Jun;39(6):299-309.

Questions and answers about persons with intellectual disabilities in the workplace. US Equal Employment Opportunities Commission website. Available at:
...(Click grey area to select URL)
Accessed January 27, 2021.

Last reviewed December 2020 by EBSCO Medical Review Board Rimas Lukas, MD
Last Updated: 1/27/2021

EBSCO Information Services is fully accredited by URAC. URAC is an independent, nonprofit health care accrediting organization dedicated to promoting health care quality through accreditation, certification and commendation.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

To send comments or feedback to our Editorial Team regarding the content please email us at healthlibrarysupport@ebsco.com. Our Health Library Support team will respond to your email request within 2 business days.