The term intellectual disability, also known as mental retardation, refers to any number of congenital or acquired mental handicaps that occur under the age of 18. The cause of a intellectual disability ranges from fetal alcohol syndrome to chromosome issues to head injuries. While symptoms vary based on the severity of the intellectual disability, a diagnosis is typically based on an intelligence quotient (IQ) score of 70 or below, coupled with at least two mental impairments that affect one's day-to-day life. Intellectual disabilities cannot technically be treated because they are not a disease. The majority of cases can, however, be managed sufficiently to allow for a reasonable quality of life.
Intellectual disability can be caused by chromosomal abnormalities present before birth, such as Down's syndrome and Wolf-Hirschhorn syndrome as well as brain abnormalities. In can also be caused by drug or alcohol abuse during pregnancy as well as fragile X syndrome and prolonged asphyxiation during labor and delivery. Intellectual disabilities can also occur after birth, most commonly as a result of meningitis or a severe head injury.
A person with an intellectual disability often has oral delays, memory lapses, difficulties with problem solving, and issues with realizing, understanding, accepting, and practicing social rules. The person may have trouble learning things that those without an intellectual disability find relatively easy; in many cases, the intellectually disabled person cannot learn these things at all.
Intellectual disabilities are categorized by four subgroups: mild, moderate, severe, and profound. Those with mild intellectual disabilities have an IQ score of 50 to 69 and typically require some type of aid during their lifetime, although many are capable of caring for themselves in day-to-day tasks. Persons with a moderate disability have an IQ score of 35 to 49 and typically require aid in many daily tasks, although they can often live well in group home settings during adulthood.
Those with IQ scores of 20 to 34 are classified as severe and typically require a primary caregiver for their entire life. Profound cases of intellectual disabilities include persons with an IQ score of below 20. These individuals often cannot walk or speak coherently and typically require intensive care for their entire life. Any IQ score under 70, when coupled with social issues or the inability to care for oneself, is considered an intellectual disability.
There is no typical treatment for an intellectual disability. Programs such as early intervention, behavioral therapies, and specialized classes often provide these persons with the greatest chance of living as independently as they are capable. In some cases, especially severe and profound cases, these therapies are of little to no help in developing independence. Many people with intellectual disabilities can eventually work and live on their own and can function safely in society. Many, however, require the care of family members, or local government or charities, to care for them in some capacity or another.