Types of Mental Retardation – Different Classifications of the Condition
Posted Sep 01 2012 10:13am
Mental retardation doesn’t affect different patients in the same way. The condition may exist with varying intensities and in the form of diverse mental and behavioral disabilities. Depending on the root causes and associated symptoms, there are different types of mental retardation. Finally, the condition can be classified on the basis of the levels of intelligence quotient. Here are the details of these classifications:
Syndromic and Non-syndromic
The symptoms shown by a patient may or may not include those of other factors in addition to the intellectual disabilities. On this basis, the two types of mental retardation include:
Syndromic: Apart from the intellectual disabilities, other symptoms like abnormal shapes of body organs are also found in the patients suffering from syndromic mental retardation.
Non-Syndromic: In this type, only intellectual disabilities are exhibited by the affected patients.
IQ Based Qualification
I ntelligence quotient forms the important basis of assessments used to distinguish mentally retarded children from the normal ones. It is worth mentioning that the IQ score of 100 is considered as equivalent to normal intelligence. The individuals showing IQ score between 70 and 85 are known to possess below average intelligence, though the level is not considered as equivalent to mental retardation. This means that mentally retarded individuals have IQ score below 70. Here is the classification on the basis of different ranges of IQ scores:
Mild Retardation: It is the most common among the types of mental retardation, as it is found to affect nearly 75-85% of the total cases. So, what is mild mental retardation? The condition corresponding to the IQ score ranging from 50 to 69 defines this type. These patients can learn academic skills up to grade 6 and may later lead a self-dependent life, with the help of community and special training support.
Moderate Retardation: In this type, the IQ score is found to range from 35 to 49. Nearly 10% of the total cases belong to this category. These patients can attain the academic skills up to grade 2 only. During the adult age, these individuals can be taught the self-care skills.
Severe Retardation: Up to 4% of the mentally retarded patients show the IQ score from 20 to 34 and are known to suffer from severe retardation. Basic tasks can be taught to these individuals under close supervision only.
Profound Retardation: There are about 2% of the patients suffering from this type of mental retardation in which instability rules the minds of these patients. For their demand of constant care, these patients are admitted to special institutes.
Types Resulting from Different Causes
Mental retardation may occur due to several reasons and some of the conditions resulting from these causes are given special classification. Here are some types of mental retardation in this regard:
Down syndrome Retardation: Also called Mongolism, the condition occurs due to chromosomal anomalies.
Phenylketonuria: The condition occurs due to the brain damage caused by phenylalanine amino acid which is not broken due to the absence of an important enzyme.
Cranial Abnormalities: Though the exact causes of these conditions are not known, the patients show abnormal size of head and brain while suffering from these types of mental retardation. The sub-types include microcephaly (smaller than normal head size) and macrocephaly (larger than normal head size).
Cretinism: The mental retardation condition caused by the deficiency of iodine is called cretinism.
Asperger’s Syndrome: The condition in which the children are not able to develop social skills.
Mental retardation types may differ in terms of causes, symptoms and IQ levels, but each of them requires management through special techniques. Discuss these conditions with a qualified mental health expert to obtain more useful information.