Intellectual disability, once commonly referred to as mental retardation and sometimes called developmental delay, is characterized by below-average intelligence and a lack of necessary skills to function in daily life. Intellectual disability is detected and diagnosed before the age of 18 and, often, can be identified before birth. In adults, the onset of symptoms similar to intellectual disability is known as dementia.
Signs of an intellectual disability may include the slow development of motor or language skills (walking and talking), behavioral problems, trouble keeping up in school, a lack of curiosity, difficulty with following rules or connecting actions with consequences. Behavioral counseling from a qualified mental health professional is often very helpful for individuals with intellectual disability.