Many autistic children have some degree of mental impairment. When tested, some areas of ability may be normal or superior, while others may be especially weak. For example, an autistic child may do well on the parts of the test that measure visual skills but earn low scores on the language subtests.
Mental retardation isn't a mandatory feature of autism, but probably about 50% of autistic children score in the mentally retarded (IQ 70 or lower) range on IQ tests. There is great variation on IQ tests among those who have autism, with a common finding being that those with autism have a higher nonverbal IQ and a much lower verbal IQ. Often this pattern is reversed in those who have Asperger syndrome. In the past, the percentage of children with mental retardation was higher (70%) because the diagnosis of autism was only used in more severely affected children. As more mildly affected children get included on the autism spectrum, the percentage of those with normal IQs also increases.
IQ test results are much more uneven in the sub-categories than normal, frequently showing a peak in visuo-spatial tasks and those that require rote memory. Because of this an autistic person may have much more skill in doing certain things than his IQ seems to indicate, and when taken to the extreme, the person may be called an autistic savant.
There are things like echolalia that separate autistic children from mentally retarded people.
More about the Autism Spectrum Test
Although the American Association on Mental Retardation continues to use the term mental retardation .The term "Mental retardation" has acquired pejorative and shameful connotations over the last few decades and is now used almost exclusively in technical or scientific contexts. Some of the alternative terms to describe the condition of mental retardation are:
- In North America the broad term developmental delay has become an increasingly preferred synonym for mental retardation. Elsewhere, however, developmental delay is generally used to imply that appropriate intervention will improve or completely eliminate the condition, allowing for "catching up." Importantly, this term carries the emotionally powerful idea that the individual's current difficulties are likely to be temporary.
- Developmental disability is preferred by most physicians. However, the term also refers to any other physical or psychiatric delay, such as delayed puberty.
- The phrase intellectual disability is increasingly being used as a synonym for people with significantly below-average IQ. These terms are sometimes used as a means of separating general intellectual limitations from specific, limited deficits as well as indicating that it is not an emotional or psychological disability. Intellectual disability is also used to describe the outcome of traumatic brain injury or lead poisoning or dementing conditions such as Alzheimer's disease. It is not specific to congenital conditions like Down syndrome.
According to the latest edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) (), there are three criteria before a person is considered to have a developmental disability:
- An IQ below 70,
- Significant limitations in two or more areas of adaptive behavior (i.e., ability to function at age level in an ordinary environment), and
- Evidence that the limitations became apparent in childhood.
- An IQ IQ below 70
|Profound mental retardation||Below 20|
|Severe mental retardation||20–34|
|Moderate mental retardation||35–49|
|Mild mental retardation||50–69|
|Borderline mental retardation||70–79|
Causes of mental retardation include:
- Genetic factors
- Problems during pregnancy and at birth, and use of forceps during birth
- General health problems, malnutrition, and iodine deficiency
- Sensory deprivation
- Psycho-social disadvantage
Mental retardation is not a disease - it is a disability, and is distinct from conditions of mental illness like schizophrenia or depression. There is no medicine to remove this disability though there are many programs available to reduce the impact of this disability to assist the children with MR to improve their condition and for adults to live a better life and find some sort of work which they may perform.
- ↑ Edelson, M.G. (2006). Are the majority of children with autism mentally retarded?: A systematic evaluation of the data. Focus on Autism and Other Developmental Disabilities, 21, 66-83. Reprint online at http://www.willamette.edu/dept/comm/reprint/edelson/, retrieved 15 April 2007
- ↑ "Many times, if the researchers had a child they couldn't test, they just assumed he or she was retarded and assigned a low IQ score." Professor challenges autism assumption. The Oregonian, November 25, 2006.. Retrieved 2007-02-25.