The terms used to describe 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 retardation and
mentally retarded 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 and
politically incorrect and in need of replacement.
[2] The term
intellectual disability or
intellectually challenged is now preferred by most advocates in most English-speaking countries.
Clinically, however, mental retardation is a subtype of
intellectual disability, which is a broader concept and includes intellectual deficits that are too mild to properly qualify as mental retardation, too specific (as in
specific learning disability), or acquired later in life, through
acquired brain injuries or
neurodegenerative diseases like
dementia. Intellectual disabilities may appear at any age.
Developmental disability is any disability that is due to problems with
growth and development. This term encompasses many
congenital medical conditions that have no mental or intellectual components, although it, too, is sometimes used as a euphemism for MR.
[3] Because of its specificity and lack of confusion with other conditions,
mental retardation is still the term most widely used and recommended for use in professional medical settings, such as formal scientific research and health insurance paperwork.
[4]