Mental Retardation: Causes and Signs
It’s estimated that about 3 out of every 100 children has
mental retardation. About 613,000 children in this country ages 6 to 21 have
some degree of mental retardation and need special education in school. And 1
out of every 10 children in special education has mental retardation.
What are the causes?
There are many different causes of mental retardation. They
Health problems: Certain diseases, such as whooping
cough, measles and meningitis can sometimes cause mental retardation.
Additionally, severe malnutrition can cause mental retardation, as can exposure
to toxins such as lead or mercury.
Genetic conditions: Abnormal genes that a child
inherits from parents can cause mental retardation. A few examples of these
include Down syndrome and fragile X syndrome.
Problems during pregnancy: Women who drink alcohol
during pregnancy are more likely to have a child with mental retardation. And
there are some illnesses that can cause problems in pregnancy, such as German
measles or some infections.
Problems during birth: Not getting enough oxygen
during birth can sometimes cause mental retardation.
What are the signs?
It’s important to remember that most people with mental
retardation—about 87 percent—are only a little bit slower than the average
person in learning new things and gaining skills. It might not be clear that
they have mental retardation as infants. As they get older, parents may notice
some of the following signs:
- Developing more slowly than other children—sitting up,
crawling or walking later than usual
- Learning to talk later than most other children
- Difficulty remembering things
- Difficulty understanding accepted social rules
- Difficulty solving problems
- Difficulty understanding that their actions have
People who have mild mental retardation are usually able to
get a job and live independently. They’re completely capable of having
productive, rewarding lives. They may not even be thought of as mentally
retarded by many of the people they know.
The average I.Q. score in the general population is 100.
Scores below 70 to 75 indicate mental retardation. About 13 percent of people
with mental retardation have an I.Q. below 50. These individuals will have a
harder time in school, at home with their families and in their communities. But
these people are able to learn new things and to develop in their own way. It’s
important that parents do what they can to make sure these children reach their
Read the following two articles to find out about how
schools help in dealing with mental retardation and
what parents can do to give
their child with mental retardation the best possible chances in life.
H. Kaplan, B. Sadock, J. Grebb, Synopsis of
Psychiatry, Williams and Wilkins, 1994; National Institute of Mental Health;
National Dissemination Center for Children with Disabilities;
U.S. Department of Education.