Mental Retardation

Mental retardation (MR) means a person has significantly below average intelligence. A person who is mentally retarded cannot easily change his behavior in response to certain situations or demands.

There are four levels of MR: mild, moderate, severe, and profound. These levels are measured using a standard test.

What is the cause?

Mental retardation can start anytime before a child reaches the age of 18 years. It can be caused by disease, a brain abnormality, or an injury. These causes can happen before a child is born or during childhood. For many children, the cause of their mental retardation is not known.

Some of the most common known causes of mental retardation occur before birth. These include:

• Down syndrome
• fetal alcohol syndrome
• fragile X syndrome
• genetic problems such as Cri-du-chat syndrome or Prader-Willi syndrome
• infections such as congenital cytomegalovirus
• birth defects that affect the brain such as hydrocephalus.

Lack of oxygen during birth, or a serious head injury, stroke, or infection such as meningitis during childhood can also lead to mental retardation.

If you suspect your child has MR, talk to your healthcare provider. Your provider may need to search for the cause. Some disorders require special medical care. A genetic problem may be discovered. If it is a genetic problem you may want to talk to your provider before you decide to have more children.

What kind of testing will my child have?

Some metabolic conditions, such as phenylketonuria (PKU), galactosemia, and congenital hypothyroidism, can cause mental retardation and other problems if babies with these conditions do not start treatment soon after birth. Parents can find out if a child has one of these conditions through a simple blood test. Newborns in the United States are tested soon after birth, but different states test for different conditions. Children who have these conditions can be treated with medicine or put on a special diet.

When your child is a baby, it is not always easy to figure out the degree of retardation or predict how a child will develop over time. Standardized screening tools can help find children who are at risk for developmental delays. As your child grows, tests are used to measure how well your child is developing compared to other children of the same age. If your child's intellectual age is a lot lower than your child's actual age, then he or she probably has mental retardation.

In the preschool and school-age years, your child can be given an IQ test. IQ stands for intelligence quotient. The IQ test can show the degree of mental retardation. The test helps predict how well your child will do academically and socially. Your healthcare provider or other specialists will figure out which tests are best for your child.

How will my child develop?

Most children with MR will learn new things but at a slower pace than normal. Your child's ability to function mentally, physically, and behaviorally depends on the severity of the MR. The following levels of retardation, based on IQ, are estimates of how well a person with MR will be able to function as a child and as an adult.

Mild (IQ range 55 to 69): Preschool-age children with mild MR often do not seem very different than other children to most people. However, they are slower than most children to walk, feed themselves, and talk. Children with mild MR, when given special education, can learn practical skills and useful reading and math to a 3rd- to 6th-grade level. As adults, they can usually achieve social and job skills and live by themselves. However, they may need some guidance and support during times of unusual stress.

Moderate (IQ range 40 to 54): Preschool-age children with moderate MR show noticeable delays in development of motor skills and speech. Older children can learn simple communication, health and safety habits, and self-help skills. They are not able to gain useful reading or math skills. As adults, they can do simple tasks under special conditions and can travel alone in familiar places. They usually cannot live completely by themselves.

Severe (IQ range 25 to 39): Preschool-age children with severe MR have delays in motor development and little or no communication skills. With training, these children may be able to learn basic self-help skills, such as feeding themselves and bathing. As they grow older they can usually walk. They may have some understanding of speech and some response to it. As adults, they can get used to routines, but will need direction and supervision in a protective environment.

Profound (IQ less than 24): Children with profound MR frequently have other medical problems, such as cerebral palsy, and may need nursing care. They have delays in all areas of development. They show basic emotions and with training, may be able to use their legs, hands, and jaws. These children need close supervision. As adults they usually have simple speech and may walk. They usually benefit from regular physical activity. They are unable to take care of themselves. Someone will need to give them complete support for daily living.

Most people with mental retardation will only be a little slower than average in learning new information and skills. When they are children, their limitations may not be obvious. They may not even be diagnosed as having mental retardation until they get to school. As they become adults, many people with mild retardation can live independently.

How is MR treated?

Treatment focuses on educational, behavioral, and self-help skills. It is helpful when MR is diagnosed early in a child's life, so that therapy can begin as soon as possible. However, it is never too late to begin.

Most states offer Early Intervention Programs (EIP) for children aged 0 to 3 years with MR. Some states also offer special classes to children between the ages of 3 and 5 years who have special needs. By law, all states are required to provide special education classes for school-age children with MR through 21 years of age. Every school board must tell parents their rights and follow the laws.

The school must develop an Individual Educational Plan (IEP) for each child requiring special education. This plan includes:

• educational objectives
• class placement
• a plan for checking progress
• any other special services, such as therapy or transportation.

The plan must be agreed upon by both the parent and the school.

Parents of children with MR often hear of new and different treatments through the media or friends. Your provider can help you decide if these treatments could help or harm your child.

Where can my family get help and support?

When parents hear for the first time that their child is mentally retarded, they can feel grief, anger, guilt, and many other emotions. Many families find that professional counseling helps them to cope with this upsetting news. A child's disability affects the entire family, including brothers and sisters. Many times parents also need guidance on how to tell relatives their child has MR. Your healthcare provider and local organizations can direct you to therapists and parent support groups that can help you and your family deal with these important issues.

Written by the Section of Developmental-Behavioral Pediatrics, Hackensack Medical Center's Institute for Child Development in Hackensack, New Jersey.
Published by RelayHealth.
© 2009 RelayHealth and/or its affiliates. All Rights Reserved.