In the early stages it may be very difficult to pick up mental retardation in a child. Some cases may be picked up by an astute physician or parent. But usually it is not until the infant grows older and suddenly the mother senses that her child is not measuring up or making progress as one would expect. Then the parent realizes that all is not well.
There are various classifications used that may follow on from tests. For example, a child with an IQ (Intelligence Quotient) of 80-89 is considered to be “dull normal.” From 70-79, a child is classified as “borderline defective,” and one with an IQ of 69 or below is said to be “mentally defective.”
There are many reasons attributed to it, and some have been quite uncontrollable. For example, the mother may have suffered from some kind of infection antenatally, such as when the infant’s brain was being developed. There may have been Rh blood incompatibilities, or the child may be a Down’s syndrome baby. During birth there may have been an inadequate oxygen supply for many and varied reasons.
Brain infections, the aftermath of serious infections, such as meningitis, encephalitis, herpes infections or any of the other viral or bacterial brain infections, may have played a major part. Or the child may have been subjected to toxins, chemicals, or an underactive thyroid gland. The latter, cretinism, once common, is now far less likely with routine screening of the blood of all newborn babes in many large hospitals, and adequate treatment for any adversely affected. This has proved to be a major improvement in cases due to this cause.
As the child gets older, the child cannot benefit from events that would normally educate the average person. Experience and instruction offer no benefits and the patient does not meet the standards of others in the same age group, and falls more and more behind. Often such children are antisocial and cannot cope with those of like age. So they become restive, resentful, irritable and argumentative, and may act unreliably. Testing by a specially devised system will quickly offer the diagnosis, and may indicate the extent of the problem.
Often the child is kept at home, and the parents take care of the upbringing and education, limited though this may be. Often they are prepared to spend the time and energy to make life reasonably tolerable for such children, allowing them to learn a great deal in this manner.
As they become older, these places are often the ideal. Here they receive special instruction by trained supervisors and teachers. Many ultimately develop various skills and may take their place in society, serving in a limited capacity and performing reasonably acceptable work considering their handicap.
Parent self-help groups are usually formed by parents with similar problems, and are often very active and extremely helpful. Psychologically they can offer worthwhile support for the parent as well as the child. This may be very important, especially as the child may be wholly dependent on the parents for many years to come.
In recent times, the two outstanding developments have been at-birth blood screening tests for the detection of phenylketonuria and hypothyroidism, both of which used to be notorious for producing mental retardation. This is probably the greatest single “breakthrough” in helping detect problems before they actually occur. Both are now virtually standard in every obstetrics hospital throughout the country.