Intellectual Disability

Intellectual Disability is a new term for what used to be called Mental Retardation. It manifests before the age of 18 years. It is identified by how a person does on tests to measure his/her intelligence and his/her adaptive skills.

Intelligence involves the ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly and learn from experience. Intelligence is measured by special tests called intelligence tests. These tests provide a numerical score after measuring the person’s general mental capability with reference to their age. This score is called intelligence quotient or IQ. In general, a person with an IQ test score of about 70 or below is indicative of Intellectual Disability.[1]

Intellectual Disability impacts adaptive skills, these refer to how well a person can deal with the tasks of everyday life. These include the ability to speak and understand; self-management skills (dress, bathe, feed or otherwise care for themselves, manage job responsibilities, manage money); use of community resources; leisure, self-care, and social skills (empathy, social judgement, inter-personal communication, ability to make and retain friendships); self-direction; basic academic skills (reading, writing, and arithmetic); and work skills.

A child is only considered to have Intellectual Disability if he/she displays deficits in both IQ and adaptive behaviour. He/she is not considered to have Intellectual Disability if only one of the two is present.

Recognising Intellectual Disability

What are the types of Intellectual Disability?

Persons with Intellectual Disability may have different levels of abilities and skills, with severity being categorized as:

  • Mild Intellectual Disability
    • During childhood: Develops appropriate social and communication skills; has minimal impairment in sensory-motor areas; is often not distinguishable from children without Intellectual Disability.
    • During adolescence: Acquires academic skills up to approximately the 6th class level.
    • In adulthood: Acquires social and vocational skills adequate for minimum self-support;can usually live successfully in the community; may need supervision and guidance.
  • Moderate Intellectual Disability
    • During childhood: Attains basic communication skills; can learn personal care through vocational training and moderate supervision; can benefit from training in social and occupational skills.
    • During adolescence: Has difficulty in recognising social conventions, which may interfere with peer relationships.
    • In adulthood: Able to perform unskilled or semi-skilled work under supervision, adapts well to life in the community.
  • Severe Intellectual Disability
    • During childhood: Able to communicate a little, or not at all.
    • During adolescence: Learns to talk and is trained in basic self-care skills; able to profit in a limited way from instruction in pre-academic subjects; can become familiar with the alphabet and simple counting, and can master skills such as sight-reading of some ‘survival’ words.
    • In adulthood: Able to perform simple tasks in closely supervised settings; generally adapts well to life in the community, in supervised group homes or with his/her family.
  • Profound Intellectual Disability
    • During childhood: Impaired in sensory-motor functioning; requires a highly structured environment with constant aid and supervision for optimal development; motor development, self-care and communication skills may improve if appropriate training is provided.
    • During adolescence: Cannot communicate much, speaks only a few words; cognitive abnormalities present – lacks the capacity to read, calculate or even understand what others say; significant delays in all areas.
    • In adulthood: Cannot take care of him/herself and has no language; seizures, physical disabilities, and reduced life expectancy are common; needs close supervision and attendant care.

What causes Intellectual Disability?

Intellectual Disability affects about 1 – 3% of the population. Doctors are able to identify a specific cause in only 25% of the cases even though there are over 200 known causes of Intellectual Disability.Causes can be categorized as follows:

  • Genetic conditions: Intellectual Disability may be due to genetic abnormality caused by infections during pregnancy, overexposure to x-rays and other factors; due to abnormality of genes inherited from parents, or errors when genes combine during foetal growth.[2] Conditions of this kind could be inborn errors of metabolism such as PKU (phenylketonuria); or chromosomal abnormalities such as Down Syndrome and fragile X syndrome.
  • Risk factors during pregnancy: Use of alcohol or drugs by a pregnant mother can cause Intellectual Disability. Malnutrition, rubella, cytomegalovirus, granular disorders, diabetes and many other illnesses of the mother during pregnancy may result in a child being born with Intellectual Disability. Physical malformations of the brain and HIV infection in prenatal life may also result in Intellectual Disability.
  • Risk factors at birth: The developing foetus’ brain could be injured by any birth condition or unusual stress. However, prematurity and low birth weight pose especially serious risks to the child.
  • Risk factors after birth: Childhood diseases such as whooping cough, chickenpox, measles and Hib disease, resulting in meningitis or encephalitis may damage the brain. Freak accidents such a blow to the head or near drowning, as well as substances such as lead and mercury can cause irreparable damage to the brain and nervous system.
  • Economic deprivation: Children growing up in poverty are at a higher risk to malnutrition, childhood diseases, exposure to environmental health hazards and lack of access to adequate health care. These children may also be deprived of the intellectual stimulation that educational experience provides, which research has shown can result in irreversible damage.

What are the signs and symptoms of a child with Intellectual Disability?

The most striking symptom that you will notice in your child is impairment of adaptive functioning, rather than low IQ.

Adaptive functioning refers to how effectively individuals cope with common life demands and how well they meet the standards of personal independence expected of someone in their particular age group, socio-cultural background and community setting. This often determines the ability of these young children to make friends. Adaptive functioning may be influenced by factors such as education, motivation, personality characteristics, social and vocational opportunities, and the general medical conditions and disorders that can coexist with Intellectual Disability. Remedial efforts are more likely to improve problems in adaptation than in cognitive IQ.

Some characteristics of Intellectual Disability are:

  • Sits up, crawls, or walks later than other children
  • Learns to talk late, or has trouble speaking
  • Finds it hard to remember things
  • Does not understand how to pay for things
  • Has trouble understanding social rules
  • Has trouble seeing the consequences of his/her actions
  • Has trouble solving problems
  • Has trouble thinking logically
Diagnosing Intellectual Disability

How is Intellectual Disability diagnosed? What does the assessment procedure entail?

Intellectual Disability can be diagnosed as follows:

  • During pregnancy: Certain tests such as ultrasound and amniocentesis can be performed to detect genetic problems associated with Intellectual Disability.
  • In a baby: Intellectual Disability may be suspected for several reasons. If a baby has physical abnormalities that suggest a genetic or metabolic disorder, Intellectual Disability can be confirmed by tests such as blood tests, urine tests, imaging tests to look for structural problems in the brain, or electroencephalogram (EEG) to detect evidence of seizures.
  • In a child: Where developmental delays are present, the health care provider may perform tests to rule out other problems, such as hearing problems or neurological disorders. If no cause is found for these delays, the child will be referred for formal testing. This diagnosis will include 3 elements:
    • Interviews with parents: Informal evaluations, including behavioural checklists, from which information about a child’s emotional, social and communication and cognitive abilities is gathered.
    • Observation of the child: Play-based and functional assessments which involve observing the child and family in structured and unstructured play situations, and provide information about a child’s social, emotional, cognitive and communication development.
    • Psychometric Testing of intelligence and adaptive behaviour: Formal evaluations, which include standardised tests or developmental scales.

A child is only considered to have Intellectual Disability if he/she displays deficits in both IQ and adaptive behaviour. He/she is not considered to have Intellectual Disability if only one of the two is present.

Who should I approach for a diagnosis?

Usually, Intellectual Disability can be confirmed by:

  • Paediatricians
  • Clinical psychologists
  • Developmental psychologists

What should I do post-diagnosis?

A diagnosis of Intellectual Disability in a child can be overwhelming. You may find it helpful to hear from other parents – for example, through Parent Support Groups. Learning from their experiences can be a reassuring way to adapt to the diagnosis.

After a diagnosis of Intellectual Disability is made, a team of medical professionals assesses the child. During this assessment, the child’s particular strengths and weaknesses are uncovered to help determine the amount and kind of support that the child needs, to succeed at home, in school and in the community.

General medical tests as well as specialised tests such as neurology (nervous system), psychology, psychiatry, special education, hearing, speech and vision, and physical therapy are useful. An early diagnosis coupled with training enhances the child’s progress. A child’s rate of learning will depend upon the degree of Intellectual Disability present. Formal assessment can give parents and teachers some idea about a child’s degree of Intellectual Disability.

Children with Intellectual Disability may find it hard to use their knowledge or skills in new situations. For example, a child may learn to wash his hands at home. However, he may need help to learn to do the same task at preschool or school.

Living with Intellectual Disability

Intellectual Disability in childhood

Given the right support, a child with Intellectual Disability can learn to lead a fulfilling life and make a valuable contribution to society. As a parent of a child with Intellectual Disability, you play an important role in helping your child reach their full potential. There are a number of interventions you can make at home, but you may also need to seek out professional advice and specialist support.

What is the importance of early interventions for a child diagnosed with Intellectual Disability?

Early detection and intervention is very crucial, because it promotes your child’s coping and confidence, and helps to ensure that they can function better and are successfully integrated into society. Early diagnosis helps to put plans for developmental, educational and vocational services in place, in a timely manner. Interventions include specialised therapy, providing adequate information, advocacy and emotional support for the child and the child’s family. They promote the development of your child in key domains of learning, communication and mobility. In addition, any necessary medical treatment can also be administered early.

What interventions are available for a child with Intellectual Disability?

Early intervention programs for children with Intellectual Disabilities include:

  • Family Counselling: Therapists counsel parents not only on how to cope with the child’s needs at every stage of the child’s life, but also on how to cope with their own very changed lives.
  • Speech and Language Therapy: These therapists assess, diagnose and provide therapy to children with Intellectual Disabilities to help them learn to communicate clearly.
  • Occupational Therapy: These therapists work with children to develop a comprehensive understanding of their skills and abilities to perform daily activities at home, the workplace, school or community. They evaluate and provide intervention for use of sensory, motor, cognitive, perceptual, emotional, and social skills and abilities.
  • Physical Therapy: The goal of physical therapy is to improve motor development, muscle tone and movements to help the child reach his/her motor milestones.Training with special assistive devices may be useful to teach persons with Intellectual Disabilities how to use assistive and prosthetic devices, such as canes, walkers, wheelchairs, braces, dentures, eyeglasses and hearing aids.
  • Nutrition Services: These services and interventions can reduce the risk of nutrition-related complications such as growth alteration, metabolic disorders and poor feeding skills.
  • Other Support: Sometimes, coping with the emotional and practical aspects of Intellectual Disability can be overwhelming for caregivers. Joining a support group,where parents and family members get together to share what they have learned about Intellectual Disabilities,can be helpful.

What kind of care can I provide at home?

The best place for your child to grow is in his/her own home surrounded by his/her family where he/she can be nurtured with appropriate and non-judgmental stimulation. Every person with Intellectual Disability can learn and develop physically, mentally, socially and emotionally throughout life. However, the learning will probably need more guidance, more time and need to be more structured.

Your child will likely take some time to reach certain milestones, but their achievements are significant and exciting to watch. Be patient, and encourage your young child as they learn.

Learn everything you can about your child’s Intellectual Disability. The more you know, the better an advocate you can be for your child.

  • Let your child try new things and encourage his/her independence. You can provide your child guidance when needed.
  • Give positive and frequent feedback whenever he/she masters something or learns something new.
  • Give your child chores keeping in mind his/her age and attention span and abilities, and provide assistance when needed.
  • Involve your child in group activities, such as art classes and sports, to help build his/her social skills.
  • Stay involved. Keep in regular touch with your child’s teachers to track his/her progress, and reinforce learning through practice at home.
  • Interact with other parents of children with Intellectual Disability. Join a parent support group. They can be a great source of advice and emotional support.

Should I enrol my child in a special school?

Your child has a legal right to education. These laws also protect your rights as a parent to be fully informed about or to challenge educational decisions concerning your child. Whether to send your child to a mainstream or special school is a personal decision, based on your child’s needs and your personal preferences.

Some children with Intellectual Disability can do well in a mainstream school but are likely to need individualised help. This could be in the form of Special Education or other related services, which will vary according to their abilities, environment, age and temperament. The point of Special Education in a mainstream setting is to make adaptions, accommodations, and modifications that allow a child with Intellectual Disability to succeed in the classroom and make progress in the general education curriculum. For other children, a special school will provide additional specialised help and the structure they need. Class sizes in special schools tend to be smaller, allowing for more individual attention. When choosing a school for your child, you may want to visit a mainstream school and a special school to decide which setting is better suited to your child.

Teachers and parents can help children with developmental delays and Intellectual Disabilities by[3]:

  • Using language that matches the child’s understanding.
  • Giving extra time for new skills to be learned.
  • Allowing the child, the time and opportunities to practice new skills.
  • Presenting tasks in a step-by-step manner.
  • Using predictable routines; for instance, if your child relies heavily on routine and structure, he/she may be more settled in the classroom than the playground.
  • Simplifying tasks.
  • Using teaching skills that allow child to learn by listening, touching and seeing.
  • Being clear and consistent with expectations; for instance, your child may be able to pack away his/her things at school but not at home, because a parent or sibling always does this for him/her.
  • Identifying other support structures to help the child participate at home, in school and in the community.

Intellectual Disability in adolescence

Most growing children with Intellectual Disabilities recognise that they are behind others of their age. This may result in frustration, withdrawal or anxiety, or even in depression. Since they may not have adequate language skills to talk about their feelings, their feelings could manifest in their behaviour, eating or sleeping habits.

Early diagnosis of psychiatric disorders in children with Intellectual Disability leads to early treatment and medication. Periodic consultation with a child and adolescent psychiatrist can help the family to set appropriate expectations, limits, opportunities to succeed, and other measures to manage the stress of growing up.

Many adolescents with Intellectual Disability will want to date, socialise, and form intimate relationships. You can help your child develop healthy relationships by teaching appropriate social skills and behaviour. Peer acceptance and self-esteem are affected by how well your adolescent child addresses these issues.

Here are some tips:

  • As your child enters puberty, teach them proper grooming and hygiene.
  • Encourage your child to take part in school and community activities. Teens almost always graduate from high school. Provide opportunities for your child to form healthy friendships. This is critical for your child’s happiness and sense of belonging.
  • Be aware of the social difficulties and vulnerabilities your child faces. Start early to prepare your child for healthy adult and intimate relationships.
  • Teach them about consent and how to respect their own body as well as the bodies of others.
  • Provide sex education in an honest and easy to understand manner. Talk about the reproductive as well as the intimate aspects of sex.
  • Talk about birth control and safe-sex practices to prevent sexually transmitted infections.
  • Discuss morals and beliefs with your child.

During your child’s teen years, you could also start to plan for future jobs and living arrangements. Many people who have Intellectual Disability live independently as adults or in group homes/apartments with support services. But most group homes and community centres require a basic level of self-sufficiency, such as being able to eat, dress, and bathe independently. Occupational therapists can assist in these transitions.

Vocational training helps many young adults learn how to work in many settings, such as stores, restaurants, and hotels.

Intellectual Disability in adulthood 

Most individuals with Intellectual Disability can lead at least partially independent lives. The goal is to help the person stay in the family and participate in community life.

Good health and living conditions can considerably improve a person’s life expectancy. Adults with Intellectual Disability require adequate housing and health care; they must not be marginalised or institutionalised. It is important to provide rehabilitative services, vocational opportunities and quality old-age services. This will help them to become productive members of society.

Frequently Asked Questions

Q: Is there a cure for Intellectual Disability? Is it treatable? 

Intellectual Disability has a variety of causes; many of these are known, yet only 25% of all cases have a cause that has been identified. There is no known cure for the condition.

But, by identifying the cause of your child’s condition, professionals working with your child can better develop treatment plans. Certain symptoms, such as late developing social or motor skills, may be addressed by therapy, medication, or learning support systems. Children with mild Intellectual Disability may become high functioning and self-sufficient adults. Proper care throughout childhood increases the ability to reach their highest possible level of function.

See the section on Early Interventions.

Q: Are Intellectual Disabilities preventable? How can they be prevented?

There are over 200 causes of Intellectual Disability, ranging from birth defects or brain damage to preventable causes such as environmental and medical conditions, and poverty. Some cases of Intellectual Disabilities can be prevented; however, not all cases can be prevented.

Ways in which cases of Intellectual Disability can be prevented are as follows:

  • Genetic: Prenatal screening for genetic defects and genetic counselling for families at risk for known inherited disorders can minimise the risk of inherited Intellectual Disability.A woman who has phenylketonuria (PKU) should be counselled to go on a diet restricted in phenylalanine three months prior to pregnancy to prevent Intellectual Disability in her baby.Newborn screening is undertaken to identify treatable genetic conditions.Early intervention programs with high-risk infants and toddlers have shown positive effects on intellectual functioning.
  • Social: Government nutrition programs are available to poor children in the first and most critical years of life. These programs can reduce Intellectual Disability associated with malnutrition. Early intervention in situations involving abuse will also help.
  • Toxic: It is important that young girls and boys are conscious of the harmful effects of toxins in the environment such as lead and mercury, and their role in causing Intellectual Disability. Efforts should be made to eliminate these from their environment.Increased public awareness of the risks of alcohol and drugs during pregnancy can help reduce the incidence of Intellectual Disability.
  • Infectious: The prevention of Congenital Rubella Syndrome is probably one of the best examples of a successful programme to prevent one cause of Intellectual Disability. Constant vigilance, such as limiting exposure to cat litter that can cause Toxoplasmosis during pregnancy, helps reduce Intellectual Disability from this infection.
  • Childhood Immunisation: Timely immunisation can protect children from at least six diseases that if contracted, could lead to brain damage. These include measles, mumps, pertussis (whooping cough), Hib disease, varicella (chicken pox), and pneumococcal disease.
  • Other: Preventive interventions such as child safety seats, seat belts and bicycle helmets reduce the chances of injuries and head trauma.Early comprehensive prenatal care and preventive measures prior to and during pregnancy help to prevent Intellectual Disability.Dietary supplementation with Folic Acid, taken before and during pregnancy, reduces the risk of Neural Tube Defect.

Q: Are Intellectual Disabilities hereditary?

Some cases of Intellectual Disability can be attributed to an abnormality of genes inherited from parents; errors when genes combine; or from other genetic disorders caused during pregnancy. Chromosomal abnormalities that have also been related to Intellectual Disability include Down Syndrome and Fragile X Syndrome.

Prenatal screening for genetic defects and genetic counselling for families at risk of known inherited disorders is therefore recommended.

Also see section on Genetic Counselling.

Q: Why is prenatal care important in preventing Intellectual Disabilities?

Prenatal care should begin as soon as a woman suspects she is pregnant, because the health of a baby depends to a large extent on how healthy a mother is during her pregnancy. An expecting mother should ideally obtain a general health assessment at least six months before pregnancy.

During pregnancy, a woman can protect the developing foetus[4] by:

  • Getting plenty of rest and sleep
  • Updating immunisation and reviewing medication use
  • Reviewing diet and vitamin supplementation
  • Considering genetic counselling
  • Eating nutritious food
  • Avoiding alcohol, cigarettes and drugs
  • Taking safety precautions to avoid injuries

Q: When should genetic counselling be considered? 

Genetic counselling is recommended for all pregnancies. However, it should especially be sought if:

  • The child is at risk of inheriting a genetic/chromosomal disorder because of a specific condition in the family.
  • A previous birth to either parent resulted in a child with a genetic disorder, unexplained Intellectual Disability, or birth defect.
  • The mother has had two or more miscarriages, or a baby who died in infancy.
  • The mother is 35 years or older.
  • Either partner belongs to a race or ethnic group with a high incidence of any genetic condition.
  • Partners are blood relatives.

Q: Will my child need medical tests?

A number of things are considered when making the decision to perform medical tests. Not all children require that many tests be done. Your child’s presenting concerns, past medical history, family history, physical exam, and results of our evaluation or others will determine which tests, if any, are recommended.

Q: Will medication help my child?

There is no medication to cure Intellectual Disability. Sometimes medication is used for other associated conditions or behavioural problems, such as difficulties with attention or mood.

Q: Will he be able to read and write like other children?

The majority of children with Intellectual Disability will be able to learn basic reading, writing and arithmetic, which are essential for daily living. Some persons with Intellectual Disability complete high school through open learning systems and integrated education.

Q: Is Intellectual Disability the same as Mental Retardation?

Socially, the term ‘mental retardation’ is no longer considered acceptable and therefore has been replaced by the term ‘Intellectual Disability’. ‘Mental retardation’ or the slang word ‘retard’ are degrading and offensive terms as they suggest exclusivity and inferiority. These words are used in the form of an insult, leading to a derogation of persons affected by Intellectual Disability.

Acknowledgement and References

We would like to extend our sincere gratitude to Ms. Naira Kalra who reviewed this content and whose suggestions and guidance proved immensely valuable.

The following references were used to compile the above information:

[1] Luckasson, R., Borthwick-Duffy, S., Buntinx, W. H. E., Coulter, D. L., Craig, E. M., Reeve, A., Schalock, R. L., Snell, M. E., Spitalnick, D. M., Spreat, S., & Ed.). Washington DC: American Association on Mental Retardation.

[2] When the baby is in the mother’s womb, it is called a foetus.

[3] http://www.cyh.com/HealthTopics/HealthTopicDetails.aspx?p=114&np=306&id=1876#5

[4] When the baby is in the mother’s womb, it is called a foetus.