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Intellectual Disability

What is an intellectual disability?

Children with an intellectual disability (ID) have intelligence that is below the normal range. This causes trouble with daily living skills. Daily living skills include communication, self-care, home-making, and social skills. Being able to live, work, and play independently are also daily living skills. Children with ID may also have trouble learning to read, write, and do math. They not be able to learn to care for themselves.

Children with ID may also be called developmentally disabled or mentally retarded.

What is the cause?

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

ID may result if the mother:

  • Uses drugs or drinks alcohol
  • 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 ID.

Genes are the parts inside cells that make proteins the body needs to develop and work properly. Problems with the genes can be passed from parents to children. Over 500 genetic diseases have been linked to ID:

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

Problems during childhood may lead to ID:

  • Diseases such as whooping cough, measles, and meningitis
  • 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 ID. There are about 3 males with ID to every 2 females.

What are the symptoms?

Preschool-age children with mild ID often do not seem very different than other children. However, they are slower than most children to walk, feed themselves, and talk. Most children with ID have the mild form. Children with mild ID can learn reading, writing, and math skills up to the 3rd to 6th grade level. However, they may need some guidance and support during times of unusual stress.

Preschool-age children with severe ID have delays in motor development and little or no communication skills. With training, these children can learn some basic skills such as bathing and feeding themselves by the teen years. As they grow older they can usually walk. They have very limited ability to communicate with others. Many can learn to perform simple, repetitive tasks with close supervision.

Children with the most severe kind of intellectual disability often have other medical problems, such as trouble swallowing or moving. They often 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. Most need to be supervised closely during all waking hours.

How is it diagnosed?

Newborns in the US are tested soon after birth, but different states test for different conditions. Some conditions, such as phenylketonuria (PKU), galactosemia, and congenital hypothyroidism, can cause intellectual disability and other problems if babies are not treated soon after birth. Children who have these conditions can be treated with medicine or put on a special diet.

As your child grows, tests are used to measure how well your child is developing compared to other children of the same age. ID is almost always diagnosed in childhood. Mild ID may not be recognized until a child starts school. Children with ID 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.

Intelligence tests measure 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.

How is it treated?

Treatment focuses on educational, behavioral, and self-help skills.

Most states offer Early Intervention Programs for children aged 0 to 3 years with ID. Some states also offer special classes to children between the ages of 3 and 5 years who have special needs. By law, all states must provide special education classes for children with ID through 21 years of age.

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

  • Educational objectives
  • Class placement
  • A plan to check progress
  • Any other special services, such as therapy or transportation.

Both the parent and the school must agree to the plan.

Parents of children with ID 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.

What can I do to help my child?

When parents hear for the first time that their child has an intellectual disability, they can feel grief, anger, guilt, and many other emotions. Many families find that counseling can help. A child's disability affects the entire family, including brothers and sisters.

Community resources are very important. To find these services, talk with your healthcare provider or county health department:

  • Social workers find and organize help, including possible financial aid.
  • Home healthcare agencies provide the services of nurses, medical social workers, and therapists. They also provide home health aides for personal care.
  • Out-of-home services include mental health services, transportation; and nursing facilities.

You can learn more from:

Developed by RelayHealth.
Pediatric Advisor 2013.2 published by RelayHealth.
Last modified: 2012-07-25
Last reviewed: 2012-04-16
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
© 2013 RelayHealth and/or its affiliates. All rights reserved.
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