Journalist Mark Peters noted that the term’s usage goes back to the mid-1400s, where the word described “a blockage, holding back, or slowing.” Then, in the 20th century, it began to be used in medical contexts, and Terri Mauro reported that it was even used in the first Diagnostic and Statistical Manual for Mental Disorders (DSM). However, she mentioned that it began to be evolve from a medical term that described those with intellectual disabilities to an informal way of belittling people’s intelligence.
In 2010, a federal law named “Rosa’s Law” was passed that removed the term from federal labor, health, and education policies. These terms were replaced with “individual with an intellectual disability” and “intellectual disability.” The law’s text can be found on the U.S. Congress’s website. Terri Mauro also reported that the DSM-5 did not include this term.
Always try to specify the type of disability being referenced. Otherwise, the term “intellectually disabled” is acceptable. Use people-first language. Ask the person which terms they prefer.
At times, words that are considered outdated may be appropriate because of the story’s historical context. In those cases, attribute the term or note its historic use. For example, “The doctor said he was retarded, a term widely used at the time.”