Mental Retardation

What is mental retardation?

People with mental retardation (MR) have below average intelligence. They also have trouble with daily living skills. Daily living skills include communication, self-care, home-making, social skills, reading, writing, and math. Being able to live, work, and play independently are also daily living skills. People with MR may not be able to learn or to care for themselves.

People with MR may also be called developmentally disabled (DD).

What is the cause?

Many genetic, prenatal, and childhood problems cause MR. In about one third of the people with MR the cause is unknown.

The most common cause of MR during pregnancy is drug or alcohol use by the mother. MR may also result if the mother:

• has illnesses such as syphilis or German measles (rubella)
• eats a poor diet
• is exposed to toxic chemicals while she is pregnant

Loss of oxygen to the baby for a long time during birth, such as when the umbilical cord is wrapped around the neck, may cause brain damage which results in MR.

Over 500 genetic diseases have been connected with MR:

• Fragile X Syndrome
• Down Syndrome
• PKU (phenylketonuria)
• Tay-Sachs Disease

Problems during childhood may lead to MR:

• diseases such as whooping cough, measles, and certain kinds of bacteria
• accidents such as a blow to the head or near drowning
• exposure to lead, mercury, and chemical fertilizers
• poor diet and neglect

These problems show up before age 18. Only about 1% of adults have MR. There are about 3 males with MR to every 2 females.

What are the symptoms?

The 4 levels of mental retardation are: Mild, Moderate, Severe, and Profound.

• Mild Retardation. About 87% of people with MR have the mild form. People with mild MR have an IQ of between 50 and 75. Most can learn reading, writing, and math skills up to the 3rd to 6th grade level. With some help, most can successfully live by themselves and hold simple jobs.
• Moderate Retardation. About 10% of people with MR have moderate retardation. People with moderate MR have an IQ between 35 to 60. Most cannot learn basic reading and writing skills beyond simple words. Many can do simple self care tasks with some supervision. They usually have great trouble with social skills and need help in social situations. They cannot live alone. Most people with moderate MR can do simple, repetitive jobs with supervision.
• Severe Retardation. People with severe retardation have an IQ between 20 to 40. By the teenage years most can learn some basic skills such as bathing and feeding themselves. They have very limited ability to communicate with others. Many can learn to perform simple, repetitive tasks with close supervision.
• Profound Retardation. With an IQ of below 25, people with profound retardation usually have very limited or no language. They can respond to only simple commands. Most have problems with walking, speaking, or controlling basic movements. Most need to be supervised closely during all waking hours.

How is it diagnosed?

MR is almost always diagnosed in childhood. Mild MR may not be recognized until a child starts school. Adults with MR should be tested every few years to check the progress made from education and training. It is important to test both IQ and life skills. Usually a psychologist or developmental specialist does the testing.

IQ testing with adults is almost always done with the Wechsler Adult Intelligence Scale. It tests skills such as reasoning, general knowledge, vocabulary, making and copying symbols, and putting puzzles together.

Life skills are usually measured with tests of communication, self help, and social skills. Common tests are the Vineland Adaptive Behavior Scales or the Adaptive Behavior Scale.

How is it treated?

There is no cure for MR. Many programs can help people with MR to learn better skills. People with MR may be slower to learn than most people, but they can increase their skills.

How long will the effects last?

MR lasts throughout life, however many people improve a great deal over time with training and guidance. Many who have mild retardation as children lead very successful adult lives.

People with MR are more likely than others to have medical problems. These problems include Alzheimer's Disease, vision problems, heart problems, muscle weakness, and hearing loss. Menopause tends to come earlier in women with MR. These problems may make it harder for adults with MR to work long hours or to take part in physical activities as they age. People with MR are also more likely to be overweight in adulthood. On average, people with MR live about 10 years less than people without MR.

What can I do to help myself or my loved one?

You can get help and training from many government agencies and private programs. All states have special programs for people with MR. The programs for adults usually start after age 21 when schools no longer provide services. Job training and coaching programs are available through each state's Division of Vocational Rehabilitation. Private organizations like Goodwill and The ARC also offer services in many locations.

You can learn what is available through the national and local chapters of The ARC.

The ARC
Telephone: 1-800-433-5255
Web site: http://www.thearc.org.

When to get immediate help

Get immediate help if someone with MR becomes violent or begins to harm themselves. Sometimes people with MR bang their heads or other body parts against things. You will need help to restrain them so they don't hurt themselves.