Definitions of mental retardation have varied widely over the years and from discipline to discipline. The AAMR definition of mental retardation states that
Mental retardation refers to substantial limitations in present functioning. It is characterized by significantly sub average intellectual functioning, existing concurrently with related limitations in two or more of the following applicable adaptive skills areas: communication, self care, home living, social skills, community use, self direction, health and safety, functional academics, leisure, and work. Mental retardation manifests before the age of 18.
The most common are:
- Genetic conditions.
- Problems during pregnancy.
- Problems at birth.
- Health problems.
Mental retardation is not a disease. Mental retardation is also not a type of mental illness, like depression. There is no cure for mental retardation. However, most children with mental retardation can learn to do many things. It just takes them more time and effort than other children
Mental retardation is diagnosed by looking at two main things. These are:
- the ability of a person's brain to learn, think, solve problems, and make sense of the world (called IQ or intellectual functioning); and
- Whether the person has the skills he or she needs to live independently (called adaptive behavior or adaptive functioning).
Intellectual functioning, or IQ, is usually measured by a test called an IQ test. The average score is 100. People scoring below 70 to 75 are thought to have mental retardation. To measure adaptive behavior, professionals look at what a child can do in comparison to other children of his or her age. Certain skills are important to adaptive behavior. These are:
- Daily living skills, such as getting dressed, going to the bathroom, and feeding one's self;
- Communication skills, such as understanding what is said and being able to answer;
- Social skills with peers, family members, adults, and others.
As many as 3 out of every 100 children in the country have mental retardation
There are many signs of mental retardation.
- Sit up, crawl, or walk later than other children;
- Learn to talk later, or have trouble speaking,
- Find it hard to remember things,
- Does not understand how to pay for things,
- Have trouble understanding social rules,
- Have trouble seeing the consequences of their actions,
- Have trouble solving problems, and/or
- Have trouble thinking logically.
About 87% of 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. Other people may not even consider them as having mental retardation.
The remaining 13% of people with mental retardation score below 50 on IQ tests. These people will have more difficulty in school, at home, and in the community. A person with more severe retardation will need more intensive support his or her entire life. Every child with mental retardation is able to learn, develop, and grow. With help, all children with mental retardation can live a satisfying life.
Difficulties with education and training:
A child with mental retardation can do well in school but is likely to need individualized help.
For children up to age three, services are provided through an early intervention system. Staffs work with the child's family to develop what is known as an Individualized Family Services Plan, or IFSP. The IFSP will describe the child's unique needs. It also describes the services the child will receive to address those needs. The IFSP will emphasize the unique needs of the family, so that parents and other family members will know how to help their young child with mental retardation.
For eligible school-aged children (including preschoolers), special education and related services are made available through the school system. School staffs will work with the child's parents to develop an Individualized Education Program, or IEP. The IEP is similar to an IFSP. It describes the child's unique needs and the services that have been designed to meet those needs.
Many children with mental retardation need help with adaptive skills, which are skills needed to live, work, and play in the community. Teachers and parents can help a child work on these skills at both school and home. Some of these skills include:
- communicating with others;
- taking care of personal needs (dressing, bathing, going to the bathroom);
- health and safety;
- home living (helping to set the table, cleaning the house, or cooking dinner);
- social skills (manners, knowing the rules of conversation, getting along in a group, playing a game);
- reading, writing, and basic math; and
- As they get older, skills that will help them in the workplace.
Interpretation of the IQ scores
The DSM-IV classification system continues to describe those with mental retardation in terms of degrees of severity that reflect the measured level of intellectual functioning. Four degrees of severity are employed, with a fifth category reflecting situations in which the person's
- mild mental retardation, with IQ levels of 50-55 to approximately 70
- moderate mental retardation with IQ levels of 35-40 to 50-55,
- severe mental retardation, with IQ levels of 20-25 to 35-40,
- profound mental retardation, with IQ levels below 20 or 25 and
- Mental retardation, severity unspecific.
In early childhood mild disability (IQ 60-70) may not be obvious, and may not be diagnosed until they begin school. Even when poor academic performance is recognized, it may take expert assessment to distinguish mild mental retardation from learning disability or behavior problems. As they become adults, many people can live independently and may be considered by others in their community as "slow" rather than "retarded".
Moderate disability (IQ 50-60) is nearly always obvious within the first years of life. These people will encounter difficulty in school, at home, and in the community. In many cases they will need to join special, usually separate, classes in school, but they can still progress to become functioning members of society. As adults they may live with their parents, in a supportive group home, or even semi-independently with significant supportive services to help them, for example, manage their finances.
Among people with intellectual disabilities, only about one in eight will score below 50 on IQ tests. A person with a more severe disability will need more intensive support and supervision his or her entire life.
The limitations of cognitive function will cause a child to learn and develop more slowly than a typical child. Children may take longer to learn to speak, walk, and take care of their personal needs such as dressing or eating. They will have trouble learning in school. Learning will take them longer, require more repetition, and there may be some things they cannot learn. The extent of the limits of learning is a function of the severity of the disability.
Nevertheless, virtually every child is able to learn, develop, and grow to some extent.
By most definitions it is more accurately considered a disability rather than a disease. Currently, there is no "cure" for an established disability, though with appropriate support and teaching, most individuals can learn to do many things.
Although there is no specific medication for "mental retardation", many people with developmental disabilities have further medical complications and may take several medications. Beyond that there are specific programs that people with developmental disabilities can take part in wherein they learn basic life skills. These "goals" may take a much longer amount of time for them to accomplish, but the ultimate goal is independence. This may be anything from independence in tooth brushing to an independent residence. People with developmental disabilities learn throughout their lives and can obtain many new skills even late in life with the help of their families, caregivers, clinicians and the people who coordinate the efforts of all of these people.