What are the causes?
There are many different causes of mental retardation. They include:

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 consequences

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 potential.

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.

Source:
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.