This developmental disability affects roughly three percent of the population. People with mental retardation function at below-average intellectual levels, as measured by IQ tests and other psychological assessment techniques.
Three-fourths of people with mental retardation are classified as "mildly retarded." These individuals, whose IQ test scores fall between 52 and 68 (compared to an average score of 100 in the general population), usually are able to live independently or semi-independently as adults, provided they have the right kind of training as children.
WHEN SHOULD I SUSPECT THAT MY CHILD IS MENTALLY RETARDED?
Children who are mentally retarded achieve several developmental milestones more slowly than their peers. Thus, they may not master such skills as sitting and walking (which usually occur in the first year of life) until well after their first or even second birthdays. Speech also develops quite slowly; severely retarded children may never learn to talk spontaneously.
Mental retardation usually becomes apparent during the first or second year of life. Although normal children develop at vastly different rates, a clear pattern of lags in several areas suggest a problem. Other disorders, including behavior problems, autism and neurological problems, are often associated with retardation.
WHAT CAUSES MENTAL RETARDATION?
Most mental retardation is probably caused by a combination of genetic and environmental factors. In about five percent of cases, a specific genetic cause is known. Down's syndrome, which occurs when a baby has one extra chromosome (one of the structures in the nuclei of all cells that hold and transmit genetic information), is the most common identified genetic cause. Almost as common, particularly among males, is fragile X syndrome, in which a segment of the X chromosome (one of the chromosomes that determines gender) is abnormal. Children with this syndrome vary in intelligence form the low end of the normal range to severely deficient. They have a number of distinctive physical characteristics, such as a protruding tongue, stubby fingers and eyelids that appear to slant upward. Children with Down's syndrome also have a high frequency (30 to 40 percent) of congenital heart defects. The likelihood of having a baby with Down's syndrome is greater among women over 35 than among younger women, and it increases with advancing maternal age.
Certain diseases or infections in the mother can also result in mental disabilities in the baby, as can maternal abuse of drugs or alcohol. Difficulties in the birth process (for example, premature birth, birth injuries and temporary oxygen deprivation) sometimes result in mental retardation, as well.
HOW CAN THE DOCTOR TELL IF MY CHILD IS MENTALLY RETARDED?
If you suspect that your child's development is significantly delayed, get testing as soon as you can. Your doctor can do an initial screening based on motor skills achievement and social responsiveness. If the doctor suspects a disability, he may refer you to a psychologist or other mental health expert who can give your child a number of tests of intelligence and adaptive behavior, which comprises social and self-care skills, to determine the severity of the problem.
WHAT TREATMENTS ARE AVAILABLE?
Children with mental retardation can receive help from an array of public, private and non-profit agencies that specialize in developmental disabilities. Mental retardation is a lifelong condition for which there is no cure. However, retarded children are able to learn, and many can have happy and rewarding lives. Teaching should begin in infancy with early intervention enrichment programs that focus on sensorimotor development.
All states are now required to have early intervention programs for developmentally disabled children beginning at birth, and the public schools must provide special education beginning at the age of three. These programs teach skills, such as toilet training, self-feeding, dressing and speech. As children move up through school, daily living skills, as well as reading and speech, are taught.
If other conditions coexist with retardation, these conditions also need treatment. A child with seizures needs medication, and a child with behavior problems may need counseling and behavior modification.
COPING WITH A MENTAL DISABILITY
• A mentally disabled child needs the same love and support as any other child.
• Don't expect your child to keep up with peers, but don't set your expectations too low. Retarded children can learn.
• Become an advocate for your child. Find the best school setting and make sure it provides needed training. Explore and use any community services that could help your child, including schools, camps and recreational and vocational programs.
• Don't be burdened by guilt or depression. If you feel stressed, frustrated or unhappy, get help. Turn to parent groups for support.
LONG-TERM OUTLOOK
Most people with mental retardation can live rewarding and productive lives. With the necessary skills for taking care of themselves and relating to others, mildly retarded people can hold jobs and live on their own. Moderately retarded and some severely retarded people can learn to work in certain settings geared toward their abilities and live in goup homes or similar residences. There they can learn to do some things for themselves, such as dressing and preparing simple meals. They can often go out alone, shop and attend recreational activities. Most important, they can make and maintain friendships. Severely retarded people will always need fulltime care but even they can continue to learn as long as someone will teach them.
