CONCEPT OF MENTAL RETARDATION/INTELLECTUAL IMPAIRMENT

Mental retardation (MR) is a condition diagnosed before age 18, usually in infancy or prior to birth, that includes below-average general intellectual function, and a lack of the skills necessary for daily living. When onset occurs at age 18 or after, it is called dementia, which can coexist with an MR diagnosis.

Causes of ID can include:

- trauma before birth, such as an infection or exposure to alcohol, drugs, or other toxins.

- trauma during birth, such as oxygen deprivation or premature delivery.

- inherited disorders, such as phenylketonuria (PKU) or Tay-Sachs disease.

- chromosome abnormalities, such as Down syndrome

- poverty leading to malnutrition or inadequate medical care 

Someone with intellectual disability has limitations in two areas. These areas are:

Intellectual functioning: Also known as IQ, this refers to a person’s ability to learn, reason, make decisions, and solve problems.

Adaptive behaviors: These are skills necessary for day-to-day life, such as being able to communicate effectively, interact with others, and take care of oneself.

IQ (intelligence quotient) is measured by an IQ test. The average IQ is 100, with the majority of people scoring between 85 and 115. A person is considered intellectually disabled if he or she has an IQ of less than 70 to 75.

To measure a child’s adaptive behaviors, a specialist will observe the child’s skills and compare them to other children of the same age. Things that may be observed include how well the child can feed or dress himself or herself; how well the child is able to communicate with and understand others; and how the child interacts with family, friends, and other children of the same age.

Intellectual disability is thought to affect about 1% of the population. Of those affected, 85% have mild intellectual disability. This means they are just a little slower than average to learn new information or skills. With the right support, most will be able to live independently as adults.

What are the signs of intellectual disability in children?

There are many different signs of intellectual disability in children. Signs may appear during infancy, or they may not be noticeable until a child reaches school age. It often depends on the severity of the disability. Some of the most common signs of intellectual disability are:

Rolling over, sitting up, crawling, or walking late

Talking late or having trouble with talking

Slow to master things like potty training, dressing, and feeding himself or herself

Difficulty remembering things

Inability to connect actions with consequences

Behavior problems such as explosive tantrums

Difficulty with problem-solving or logical thinking.