This definition has been challenged because it does not take account of environmental and social factors, both of which may have an important influence on retardation. The lack of a clear definition has significance, for failure to diagnose may lead to failure to treat.
The problem of mental handicap emerged in the 19th century. Before that time, the handicapped were assimilated into the general background of rural societies or they did not survive at all. The percentage of children who were mildly mentally handicapped increased with the growth of towns, because of poor housing, lack of care before, during, and after birth, malnutrition, poverty, and poor working conditions for mothers. These causes remain, but, with the improvement of general standards of living and literacy, children handicapped in this way are now among the 'ablest' of the mentally handicapped. As societies become more complex and technologically oriented, the number of people unable to cope with life increases, and the burden on the working population is correspondingly increased.
In the 19th century many schemes to train and educate the mentally handicapped were begun and found to be successful. Possibly the first attempts at education were made by Jean-Marc-Gaspard Itard, who described his work with a wild boy found in the woods of Aveyron. Truffaut's film L'Enfant sauvage is an account of Itard's attempts to socialize and educate the boy Victor, who was, however, probably already handicapped when he was found.
Since the success of treatment depends very much on the cause of the illness, improved skills in diagnosing mental handicap have also meant improved chances of rehabilitation. The aetiology of mental handicap is divided into two parts: intrinsic and extrinsic causes.
1. Intrinsic causes
2. Extrinsic causes
3. Treatment and provisions
1. Intrinsic causes
These are biological, mainly genetic. One of the commonest is Down's syndrome (mongolism), which results from a chromosome abnormality. One birth in 250 will have a chromosome abnormality, which can be diagnosed by counting the chromosomes taken in smears. Unfortunately the cause of the damage to the chromosome structure that produces Down's syndrome has not yet been identified, although a connection with infective hepatitis has been suggested. Genetic counselling may reduce the incidence of one type of Down's syndrome, for if one or both parents have an abnormal chromosome structure there is a greater likelihood that their child will have an abnormality. The chances of an abnormal birth increase with the age of the mother, and after the age of 35 special attention should be paid to the chromosomal compatibility of the parents.Other intrinsic causes are metabolic. In phenylketonuria (PKU), which occurs in one in 10,000 births, failure to metabolize the amino acid phenylalanine results in a toxic condition which affects the brain and causes retardation unless a phenylalanine-free diet is given to the child. In the United Kingdom, every newborn baby is now tested for PKU, and so a dangerous condition is prevented by early intervention. Osteogenesis imperfecta ('brittle bones'), Tay–Sachs disease, and Duchenne's muscular dystrophy (both degenerative killing diseases) are other intrinsic causes of mental retardation. The causes of many intrinsic diseases are not yet known. The American Association on Mental Deficiency (AAMD) and the American Psychiatric Association maintain lists of most of the categories of intrinsic causes of retardation, and these lists are updated as knowledge extends.
2. Extrinsic causes
These are mental handicaps that result from infections, accidents, poisoning, or other brain damage. Difficult or premature births may cause brain damage because of anoxia (shortage of oxygen supply to the brain). Babies may be born blind and/or mentally retarded if the mother is infected with rubella (German measles) before the fourth month of pregnancy. Congenital syphilis can also damage the child. (It used to be thought that this disease was the cause of Down's syndrome. The misery and anxiety such a mistaken belief must have caused parents whose children suffered from Down's syndrome can hardly be imagined.) Smoking, excessive use of alcoholic drinks, poor prenatal care, malnutrition, infection, or poisoning from environmental pollution (such as mercury or lead) may lead to immature or damaged babies.During the neonatal period, factors such as high fever, jaundice, failure to breathe properly, or inadequate or unsuitable nutrition may cause retardation. The child's brain may be damaged by poisoning from sucking toys painted with paint containing lead monoxide or cadmium, or by baby battering (see child abuse), or by falls. One category in the AAMD list should be looked at with particular attention: diseases and conditions due to unknown or uncertain factors with structural reaction alone manifest — a category into which the 'wild boy' of Aveyron might well fit. It is known that a child deprived of tender loving care will grow up with deficient sensory and social ability. If the impoverishment and lack of stimulus in a child's upbringing are not remedied early, he will grow up with reduced social and intellectual capacity and may be diagnosed as a case of 'mild' (category I) retardation. Autism is a condition which may fit into any of the categories of retardation, from I to V, and which causes great distress — particularly, perhaps, as at first sight the child may seem to be quite normal. There continues to be much debate about the nature and causes of autism.
3. Treatment and provisions
The amount of handicap in individual cases varies as much as intelligence does among 'normal' people, and this range makes management and discussion complex and difficult. Diseases caused by poisoning (intoxication) may be halted or even cured by removing the source of the poison, and eliminating the poison already in the child, before there is irreversible brain damage. Diseases caused by social factors — such as malnutrition, lack of care before, during, or after birth, poor stimulus, or infection of the mother — could be eliminated or at least reduced by social welfare programmes (for example, inoculation against measles and rubella) and by the education of parents to help counter retardation of this kind.Treatment of intrinsic causes is more difficult because the damage is irreversible. However, prevention is beginning to be possible. Amniocentesis can be used to detect chromosome abnormalities while the child is still in the womb. The technique cannot be used until the fourth month of pregnancy, and, as the fluid has to be taken out of the uterus, there is the possibility of damage to a normal fetus and the risk of natural abortion; also it must be practicable to offer induced abortion as an alternative. Once a child is born with irreversible brain damage, drugs can help to prevent fits and special programmes can help to develop existing intelligence and mobility. The Doman–Delacato course of treatment may improve the abilities of some children, although it demands tremendous dedication and energy on the part of the parents, while the cost to the family as a whole should not be disregarded. More usually, brain-damaged children go to nursery schools and then to special schools where attention is paid to individual differences and needs. If this sort of help is given from birth onwards it may be possible to educate the child and support the family who look after him. In the United Kingdom such programmes have been devised by Mr R. Brinkworth, the founder of the Down's Babies Association.
In some parts of the world there are excellent provisions, while in others they are sadly lacking or even non-existent. At best the mentally handicapped may be helped to lead relatively normal lives, to do some sort of work, and to live in sheltered housing with some support. Whether the work is in workshops or on the land, it will give the moderately handicapped a sense of individual dignity and purpose. The severely handicapped will have to spend their lives in hospitals and will need dedicated nursing as well as support from all the other social services. It is important to distinguish here between the mentally handicapped and the mentally ill (see mental illness). In the popular mind these two conditions are often confused, leading to much ill-informed fear and prejudice. None the less, there is good evidence that the mentally handicapped do have a higher incidence of neurotic and psychotic disorders.
Wherever adequate provision is made for the mentally handicapped, it will be found that the cost is great. Against this cost must be set the cost of not providing. The incidence of broken marriages is ten times higher where there is a mentally handicapped child. There are risks to physical and mental health — mothers typically suffer more than fathers, while the normal children in the family are also under pressure. Widows and deserted wives figure prominently in surveys.
In the past the mentally handicapped often died at birth or in early childhood. They survive into mature adulthood with the help of care before and after birth and the widespread use of antibiotics. Should doctors perhaps not strive 'officiously to keep alive' if spina bifida has been diagnosed and the child, and later the adult, is condemned to a crippled and handicapped life after operations which may relieve the symptoms but cannot cure the condition? How can we balance, for instance, the cost of keeping a mentally handicapped child against the cost of a kidney machine for a working man who supports a family? In a sensitive and civilized society, euthanasia is an emotive and difficult subject. Doctors need guidelines and support to avoid accusations of murder when they must make decisions which affect not only the individual family but society as a whole.See also subnormality.
— Pam Hannam
- Bibliography
- Adams, M. (1971). Mental Retardation and its Social Dimensions.
- Cuckle, H. S., and Wald, N. J. (1984). 'Maternal serum alpha-fetoprotein measurement: a screening test for Down's syndrome'. Lancet, 28 Apr.
- Grossman, H. J. (ed.) (1983). Classification in Mental Retardation.
- Heston, L. L. (1982). 'Alzheimer's dementia and Down's syndrome: genetic evidence suggesting an association'. Annals of the New York Academy of Sciences, 396.
- Kemp, R., and Henry, C. (1978). Child Abuse.
- Kurtz, R. (1977). Social Aspects of Mental Retardation.
- McNamara, J., and McNamara, B. (1977). The Special Child Handbook.
- Stone, J., and Taylor, F. (1977). A Handbook for Parents with a Handicapped Child.
- Warnock, M. (1978). Meeting Special Educational Needs.
