Intellectual disability (ID), also called
intellectual development disorder (IDD) or
general learning disability (UK and Ireland),
[1] and formerly known as
mental ******ation (MR),
[2][3][4] is a generalized
neurodevelopmental disordercharacterized by significantly impaired
intellectual and
adaptive functioning. It is defined by an
IQ score
below 70 in addition to deficits in two or more
adaptive behaviors that affect everyday, general living. Once focused almost entirely on
cognition, the definition now includes both a component relating to mental functioning and one relating to individuals' functional skills in their environments. As a result of this focus on the person's abilities in practice, a person with an unusually low IQ may not be considered intellectually disabled. Intellectual disability is subdivided into
syndromic intellectual disability, in which intellectual deficits associated with other medical and behavioral
signs and symptoms are present, and
non-syndromic intellectual disability, in which intellectual deficits appear without other abnormalities.
Down syndrome and
Fragile X syndrome are examples of syndromic intellectual disabilities.
The terms used for this condition are subject to a process called the
euphemism treadmill. This means that whatever term is chosen for this condition, it eventually becomes perceived as an insult. The terms
mental ******ation and
mentally ******ed were invented in the middle of the 20th century to replace the previous set of terms, which were deemed to have become offensive. By the end of the 20th century, these terms themselves have come to be widely seen as disparaging,
politically incorrect, and in need of replacement.
[5] The term
intellectual disability is now preferred by most advocates and researchers in most English-speaking countries.
[3][4] As of 2013, the term "mental ******ation" is still used by the
World Health Organization in the
ICD-10 codes, which have a section titled "Mental ******ation" (codes F70–F79). In the next revision, the ICD-11 is expected to replace the term "mental ******ation" with "intellectual disability" or "intellectual developmental disorder," which the
DSM-5 already uses.
[6][7] Because of its specificity and lack of confusion with other conditions, the term "mental ******ation" is still sometimes used in professional medical settings around the world, such as formal scientific research and health insurance paperwork.
[8]
