Intellectual Disability
Condition
(Cognitive Disability; Developmental Disability)
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 how the brain formed, such as hydrocephalus
- 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
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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.
A child may have:
- Issues with 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 the 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 issues.
Treatment
The goal of treatment is to improve function and quality of life. There is no cure. Treatment may help 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
An intellectual disability cannot always be prevented. Proper prenatal care may lower the risk of some causes.
The Arc
Nemours Kids Health
CANADIAN RESOURCES:
Canadian Psychological Association
Special Olympics Canada
The Arc
Nemours Kids Health
CANADIAN RESOURCES:
Canadian Psychological Association
Special Olympics Canada
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.
- 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.
- Purugganan, O. Intellectual disabilities. Pediatrics in Review, 2018; 39 (6): 299-309.
- Questions and answers about persons with intellectual disabilities in the workplace. US Equal Employment Opportunities Commission website. Available at: http://www.eeoc.gov/laws/types/intellectual_disabilities.cfm.
Contributors
- James P. Cornell, MD
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