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Intellectual & Developmental Disabilities


Developmental disabilities (DDs) are often severe, lifelong conditions due to physical, learning, language or behavioral impairment. Most DDs begin before a baby is born, but some occur after birth due to injury, infection or other factors. Such disabilities can affect day-to-day functioning, include significant behavioral challenges and usually last throughout life.

DDs occur among all racial, ethnic and socioeconomic groups. Approximately 1 in 6 children, ages 3-17—about 17% of all U.S. children—has a physical or mental impairment, including:

A narrower subset of DDs are intellectual and developmental disabilities (IDDs). Starting before age 18, IDD types may vary based on the source of information—but all are typically characterized by differences with:

1. Intellectual functioning or intelligence, including ability to learn, reason, problem solve and other skills

2. Adaptive behavior, including everyday social and life skills

Children and adults with disabilities can be well, active and a part of the community. They can get the tools and information to make healthy choices, learn how to prevent illness and manage related, functional limitations in such of activities as:

Common known causes of DDs

Specific causes of most developmental disabilities are unknown and likely result from interaction between genetic, environmental and social factors:

Prenatal exposure to substances, such as smoking and drinking. Fetal alcohol syndrome is caused from maternal drinking during pregnancy

Genetic and chromosomal abnormalities, causing such conditions as Down syndrome, Rett syndrome or Fragile X syndrome 

Certain infections in pregnancy or in the baby’s first months

Increased risk for IDDs

Research has identified factors that may put children at risk for ASD and other DDs:

    • Parental health
    • Low birthweight, premature birth, multiple birth and infections during pregnancy 
    • Exposure of mother or child to high levels of environmental toxins, such as lead
    • Children with a sibling with ASD are at higher risk of having ASD
    • Untreated newborn jaundice causing brain damage and possibly cerebral palsy and hearing, vision and teeth problems

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