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Intellectual disability (ID), formerly known as mental retardation, is a disability of intellectual functioning and adaptive behaviour that can arise from conception to the beginning of adulthood. If a person has an intellectual disability, they can be significant limitations in both intellectual ability and adaptive behaviour, which manifests before the age of 18. People with ID do not look different from others. However, the difference is that they have substantial limited intellectual functioning usually an IQ that is at least two standard deviations (SD) below the mean and adaptive behaviour is also at least two SDs below the mean. Two Standard Deviations approximates 2nd to 3rd percentile, which characterises intellectual and adaptive functioning as less well-developed than approximately 97% of the population (Luckasson, in Encyclopaedia, 2016).



The result of the Life Esidimeni tragedy in South Africa (SA) raised several questions about mental health policies and practices, and about policies and practices surrounding intellectual disability (Stein, Chambers, & Daniels, et al. 2017). A few authors wanted to know whether the people responsible for mental health in SA have done enough. The authors also debated about the additional improvements that are needed in the field of psychiatry and mental health, as well as the field of intellectual disability. In recent decades, rigorous data on the prevalence of mental disorders, and their associated burden, have emerged from around the world as well as in SA (Sorsdahl, Stein, & Lund: 2012).

The above work has emphasised that there is a large treatment gap, particularly in low-resource countries. Such data, together with an emphasis on the human rights of those living with mental disorders, has helped lead to the emergence of global mental health as a key discipline (Prince, Patel, & Saxena, et al. health. Lancet 2007). A public mental health approach in SA has also led to several important advances. The Mental Health Act of 2002[5] emphasises improvements of the human rights of patients. Consistent with the World Health Organization’s Mental Health Action Plan, SA has developed a new Mental Health Policy Framework and Strategic Plan (2013 – 2020) that emphasises the value of a primary healthcare approach to reduce the treatment gap.


The causes of Intellectual Disability


Intellectual disability can be caused by any condition that impairs development of the brain before birth, during birth or through the years of childhood. Although many causes have been discovered in about one-third of the people affected, most causes remain unknown. The three major known causes of intellectual disability are Trisomy 21 (Down syndrome), Fetal Alcohol Spectrum Disorder (FASD) and Fragile X syndrome. The causes can be categorized as follows:

Genetic conditions – Genetic conditions occur when there are abnormalities in your genes. These abnormalities may be caused because you have inherited it from parents, errors when genes combine, or other disorders in genes caused during pregnancy, such as infections, overexposure to x-rays and other factors. There are many genetic diseases associated with intellectual disability; for example, PKU (phenylketonuria), a single gene disorder. Other examples of genetic disorder include Down syndrome, a chromosomal disorder, and Fragile X syndrome, a single gene disorder located on the X chromosome and is the leading inherited cause of intellectual disability.

Problems during pregnancy – Alcohol or drug abuse during pregnancy can cause intellectual disability. In fact, alcohol is known to be the leading preventable cause of intellectual disability. Recent research has implicated that smoking increases the risk of intellectual disability. Other risks include malnutrition, certain environmental toxins, and illnesses of the mother during pregnancy, such as toxoplasmosis, cytomegalovirus, rubella and syphilis.

Problems at birth – Premature birth and low birth weight cause serious problems more often than any other condition. During birth, especially during the second stage of labour, the midwife can prevent brain injuries, and prevent or diagnose foetal anoxia to early. When delivering a new-born’s head, extreme care must be taken to prevent fast extension after crowning has occurred to prevent tentorial cerebral tears. Difficulties in the birth process, such as temporary oxygen deprivation or birth injuries may cause intellectual disabilities.


Problems after birth – Childhood diseases such as whooping cough, chickenpox, measles, and Hib disease can lead to meningitis and encephalitis. Injuries such as a blow to the head or near-drowning.

Poverty and cultural deprivation – Children growing up in poverty are at higher risk for malnutrition, childhood diseases, exposure to environmental health hazards, and often receive inadequate health care. These factors increase the risk of intellectual disabilities. Also, children in disadvantaged areas may be deprived of cultural and educational experiences provided to other youngsters.


Can Intellectual Disabilities be prevented?

Early comprehensive prenatal care and preventive measures before and during pregnancy increase a woman’s chances of preventing intellectual disability. Prevention of many of the causes of intellectual disability can be prevented, which include the following:

  • Screening during pregnancy.
  • New-born screening.
  • Genetic counselling.
  • Promoting healthy diets, immunization programs, and breastfeeding during pregnancy.
  • Preventive interventions such as child safety seats and bicycle helmets reduce head trauma.
  • Early intervention programs with high-risk infants and toddlers have shown positive effects on intellectual functioning.
  • Dietary supplementation with folic acid taken before and during pregnancy reduces the risk of neural tube defects.
  • Women who have phenylketonuria (PKU) should be counselled to go on a restricted phenylalanine diet three months before pregnancy to prevent intellectual disability from occurring.


“The reality that the (intellectually disabled) person is a version of myself is one from which so much can be learned and gained, and yet, it is a reality which most people deny and try to escape from.”
― Wolf Wolfensberger