Intellectual Disability

Intellectual Disability is a condition of arrested or incomplete development of the mind, which is especially characterized by impairment of skills manifested during the developmental period, which contribute to the overall level of intelligence, i.e. cognitive, language, motor, and social abilities. It can occur with or without any other mental or physical disorder. Intellectual Disability can be categorized according to the following four levels:

Mild mental retardation: The range 50 to 69 is indicative of mild mental retardation. Mildly retarded people acquire language with some delay but most achieve the ability to use speech for everyday purposes. Most of them also achieve full independence in self-care and in practical and domestic skills, even if the rate of development is considerably slower than normal. The main difficulties are usually seen in academic school work, and many have particular problems in reading and writing.

Moderate mental retardation: The IQ is usually in the range 35 to 49. Individuals in this category are slow in developing comprehension and use of language, and their eventual achievement in this area is limited. Achievement of self-care and motor skills is also retarded, and some need supervision throughout life. Progress in school work is limited, but a proportion of these individuals learn the basic skills needed for reading, writing, and counting.

Severe mental retardation: The IQ is usually in the range 20 to 34. Most people in this category suffer from a marked degree of motor impairment or other associated deficits, indicating the presence of clinically significant damage to or maldevelopment of the central nervous system.

Profound mental retardation: The IQ in this category is estimated to be under 20, which means in practice that affected individuals are severely limited in their ability to understand or comply with requests or instructions. Most such individuals are immobile or severely restricted in mobility, incontinent, and capable at most of only very rudimentary forms of nonverbal communication. They possess little or no ability to care for their own basic needs, and require constant help and supervision.