Disabilities, Severe and Multiple

Moderate and Severe Intellectual Disabilities

The term severe disabilities might be applied to any disability category (e.g., “severe learning disability”), but it is most often associated with individuals with an intellectual disability that is substantially below average. The term intellectual disability has replaced the older term mental retardation. The newer term is more consistent with terminology used worldwide and more acceptable to stakeholders. Most major associations have changed their name to reflect the new terminology, including the President's Committee for People with Intellectual Disability (formerly the President's Committee on Mental Retardation) and the American Association on Intellectual and Developmental Disabilities (AAIDD, formerly the American Association on Mental Retardation). The 11th edition of the AAIDD Intellectual Disability: Definition, Classification, and Systems of Support manual, used to diagnose the condition worldwide, changed the term to intellectual disability in this edition. The AAIDD manual defines intellectual disability as “characterized by significant limitations both in intellectual functioning and in adaptive behavior as expressed in conceptual, social, and practical adaptive skills. This disability originates before age 18” (p. 1). Although the focus here is moderate and severe disability, it should be noted that an intellectual disability can be mild, requiring only minimal support to function in activities of daily living.