A broad category of disorders characterized by an impairment to the intelligence an individual possesses. These impairments can result from trauma, birth, or disease and are not restricted to any particular age group.

Subnormal intellectual functioning which originates during the developmental period. This has multiple potential etiologies, including genetic defects and perinatal insults. Intelligence quotient (IQ) scores are commonly used to determine whether an individual has an intellectual disability. IQ scores between 70 and 79 are in the borderline range. Scores below 67 are in the disabled range. (from Joynt, Clinical Neurology, 1992, Ch55, p28)

Intellectual disability is characterized by significantly subaverage intellectual functioning (often expressed as an intelligence quotient < 70 to 75) combined with limitations of adaptive functioning (ie, communication, self-direction, social skills, self-care, use of community resources, and maintenance of personal safety), along with...

Intellectual disability (ID) is a descriptive term for subaverage intelligence and impaired adaptive functioning arising in the developmental period (< 18 y). ID and other neurodevelopmental disabilities are seen often in a general pediatric practice.

Intellectual disability, any of several conditions characterized by subnormal intellectual functioning and impaired adaptive behaviour that are identified during the individual's developmental years. Increasingly, sensitivity to the negative connotations of the label mentally retarded prompted the...