Causes

Intellectual disabilities can be caused by injury, disease, or brain abnormalities. The past two decades have unveiled research that has increased our understanding of the etiology of intellectual disabilities. Yet, for many, the cause of their ID is unknown. Some causes of intellectual disability—such as Down syndrome, Fetal Alcohol Syndrome, Fragile X syndrome, birth defects, and infections—can happen before birth. Some happen while a baby is born or soon after birth. Other causes of intellectual disability do not occur until a child is older, including severe head injury, infections, or stroke. Below are some of the most common causes:

• (1) Genetic conditions. Sometimes an intellectual disability is caused by abnormal genes inherited from parents, errors when genes combine, or other reasons. Genetic conditions include Down syndrome, Fragile X syndrome, Williams syndrome, and Prader-Willi syndrome.
• (2) Complications during pregnancy. An intellectual disability can result when the baby does not develop inside the mother properly. For example, there may be a problem with how the baby’s cells divide. A woman who drinks alcohol or gets an infection such as rubella during pregnancy may also have a baby with an intellectual disability.
• (3) Problems during birth. If there are complications during labor and birth, such as a baby not getting enough oxygen, they may have an intellectual disability.
• (4) Diseases or toxic exposure. Diseases such as whooping cough, measles, or meningitis can cause intellectual disabilities. They can also be caused by extreme malnutrition, inadequate medical care, or exposure to poisons such as lead or mercury.

 Intellectual disabilities are not contagious: you cannot catch an intellectual disability from anyone else. We also know that ID is not a mental illness such as depression. There are no cures for intellectual disability. However, people with intellectual disabilities can learn to do many things. They may need to take more time or learn differently than others, but they can learn and grow (Vaughn & Bos, 2020).