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INTELLECTUAL DISABILITIES

Definition

Intellectual Disabilites is a developmental disability that is clinically identified through sub-average cognitive functioning and impairments in adaptive functioning that is recognized in childhood (before a person turns eighteen years old). Children with cognitive disabilities may be delayed in their development of speech, motor development and the acquisition of personal needs such as dressing and eating. Intellectual disabilities typically affects a person’s cognitive functioning, communication, adaptive skills, and social skills. It typically causes a person to learn and develop more slowly than a typically developing person.

Intellectual disabilities is clinically diagnosed based on the level of a person’s cognitive functioning. A person may have mild, moderate, severe, or profound intellectual disabilites. Whereas a person with mild cognitive disabilities is likely to acquire the skills necessary to live independently or semi-independently, a person with profound disabilities is likely to need daily support in most aspects of everyday life such as eating, toileting, and grooming.

Intellectual disabilities is not a disease nor is it a mental illness, like depression. There is no cure; however, most people with cognitive disabilites can learn to do many things. People with cognitive disabilities learn new information more slowly than people without cognitive disabilities. They may need to have information presented to them more times and in a variety of ways in order to learn.

Incidence

As many as three out of every 100 people in the United States have intellectual disabilities. Over 614,000 children ages 6 to 21 have some level of cognitive disabilities and require special education in school (Twenty-third Annual Report to Congress, U.S. Department of Education, 2001). One out of ten recipients of special education services have mental retardation.

About 87% of people with intellectual disabilities have mild cognitive disabilities. Although they learn information more slowly than an average person, their disability may not be obvious. They may not be diagnosed with intellectual disabilities until they enter school. As adults, many people with mild intellectual disabilities live independently. Other people may not regard then as having a “disability.”

The remaining 13% percent of people with intellectual disabilities have moderate, severe, or profound mental retardation. This population will have more difficulties in school, at home, and in the community. A person with severe cognitive disabilities will need more intensive supports throughout his or her entire life.

Causes

Intellectual disabilities can be caused by any condition that impairs development of the brain before birth, during birth, or during the childhood years. Several hundred causes have been discovered, but in about one-third of the people affected, the cause remains unknown. The three major known causes of mental retardation are Down Syndrome, fetal alcohol syndrome, and fragile X syndrome. The causes of cognitive disabilities can be categorized as follows:

Genetic conditions- Genetic causes of cognitive disabilities may result from genes inherited from parents, errors when genes combine, or from other disorders of the genes caused during pregnancy infections, illness, depravation, and other factors. More than 500 genetic diseases are associated with intellectual disabilities. One example is phenylketonuria (PKU). Down Syndrome is an example of a chromosomal disorder. Chromosomal disorders happen sporadically and can be caused by too many or too few chromosomes, or by changes in the typical structure of a chromosome. Fragile X syndrome is a single gene disorder located on the X chromosome and is the leading inherited cause of intellectual disabilities.

Problems during pregnancy- Use of alcohol and/or drug during pregnancy by a pregnant woman can cause intellectual disabilities. Recent research has implicated smoking in increasing the risk of intellectual disabilities. Other risks include malnutrition, certain environmental contaminants, and illness of the mother during pregnancy.

Problems at birth- Although any birth condition of unusual stress may injure an infant’s brain, prematurity and low birth weight predict serious problems more often than any other condition.

Problems after birth- Childhood diseases such as whooping cough, chicken pox, measles, and Hib disease that may lead to meningitis and encephalitis can damage the brain, as can accidents such as a blow to the head or near drowning. Lead, mercury, and other environmental toxins can cause irreparable damage to the brain and nervous system.

Poverty and cultural deprivation- Children living in serious poverty who are exposed to malnutrition, disease-producing conditions, inadequate medical care and environmental health hazards are at risk of being identified with . Research suggests cognitive disabilities that severe under-stimulation can result in irreversible damage and can serve as a cause of intellectual disabilities. Therefore, children who are deprived of many common cultural and day-to-day experiences are at risk of developing intellectual disabilities

Characteristics

There are many signs of intellectual disabilities. For example, people with cognitive disabilties may:

Sit up, crawl, or walk later than other children

Have delays in speech acquisition, or have trouble speaking

Find it hard to remember things

Have trouble understanding and following social rules

Have trouble solving day-to-day problems

Misunderstand sarcasm

Have trouble thinking logically and abstractly

Diagnosis

Cognitive disabilities is diagnosed by looking at two main areas:

1.) Intellectual/Cognitive functioning- the ability of a person’s brain to learn, think, solve problems, and make sense of the world

2.) Adaptive functioning- the skills that are necessary for a person to live independently

Intellectual functioning is typically measured through an IQ test. The average score on an IQ test is 100. People who score below 70 are thought to have cognitive disabilities. Degrees of severity of intellectual disabilities reflect a person’s level of intellectual impairment as follows:

  • Mild Intellectual Disabilities: IQ level of 50-55 to approximately 70
  • Moderate Intellectual Disabilities: IQ level of 35-40 to 50-55
  • Severe Intellectual Disabilities: IQ level of 20-25 to 35-40
  • Profound Intellectual Disabilities: IQ level below 20-25

Adaptive functioning is typically measured by comparing a person’s adaptive skills to other people her or his age. Adaptive skills include:

  • Dressing one’s self
  • Using the bathroom independently
  • Feeding one’s self
  • Communication skills
  • Personal grooming
  • Social skills with peers, family

People with intellectual disabilities have a legal right to education, to live as independently as they are able, and to non-discriminate treatment in all aspects of living. Federal law such as the Individuals with Disabilities Education Act (IDEA) provide a guide as to how schools and other service providers deliver services to people with intellectual disabilities.

Providing services to people with intellectual disabilities has led to new understanding of how we define intellectual disabilities. After the initial diagnosis is made, we look at a person’s strengths and weaknesses. We also look at how much support the person needs to get along at home, in school, and in the community. This approach gives a realistic picture of each individual. It also recognizes the person’s strengths and acknowledges that they can change.