The term developmental disability has evolved over the years from one that included specific conditions - either “mental retardation” [now known as “intellectual disability”] or conditions closely related to “mental retardation” including cerebral palsy, epilepsy, autism, and dyslexia. Eventually, developmental disability was defined in functional terms, so that anyone whose disability results in substantial functional limitations in 3 or more areas of major life activity that is manifested before the age of 22 is a person with DD. It does not necessarily mean that the person has an intellectual disability or a condition related to intellectual disability although most people with severe intellectual disabilities are likely to also fit the definition of DD. [See the history of the act.]
This is the definition of developmental disability under the DD Act of 2000:
Title I — Programs for Individuals with Developmental Disabilities
Subtitle A — General Provisions
SEC 102 Definitions
A. IN GENERAL.—The term “developmental disability” means a severe, chronic disability of an individual that—
i. is attributable to a mental or physical impairment or combination of mental and physical impairments;
ii. is manifested before the individual attains age 22;
iii. is likely to continue indefinitely;
iv. results in substantial functional limitations in 3 or more of the following areas of major life activity:
- Receptive and expressive language.
- Capacity for independent living.
- Economic self-sufficiency; and
- reflects the individual’s need for a combination and sequence of special, interdisciplinary, or generic services, individualized supports, or other forms of assistance that are of lifelong or extended duration and are individually planned and coordinated.
B. INFANTS AND YOUNG CHILDREN.—An individual from birth to age 9, inclusive, who has a substantial developmental delay or specific congenital or acquired condition, may be considered to have a developmental disability without meeting 3 or more of the criteria described in clauses (i) through (v) of subparagraph (A) if the individual, without services and supports, has a high probability of meeting those criteria later in life.
Other programs and services not covered by the DD Act may base eligibility or participation on a specific medical diagnosis, the income of the individual, or a combination of these or other factors.