A historical image of a person with intellectual disability

Intellectual disability (ID) begins during childhood and involves deficits in mental abilities, social skills, and core activities of daily living (ADLs) when compared to same-aged peers. There often are no physical signs of mild forms of ID, although there may be characteristic physical traits when it is associated with a genetic disorder (e.g., Down syndrome).

The level of impairment ranges in severity for each person. Some of the early signs can include:

• Delays in reaching or failure to achieve milestones in motor skills development (sitting, crawling, walking)
• Slowness learning to talk or continued difficulties with speech and language skills after starting to talk
• Difficulty with self-help and self-care skills (e.g., getting dressed, washing, and feeding themselves)
• Poor planning or problem solving abilities
• Behavioral and social problems
• Failure to grow intellectually or continued infant-like behavior
• Problems keeping up in school
• Failure to adapt or adjust to new situations
• Difficulty understanding and following social rules

In early childhood, mild ID (IQ 50–69) may not be obvious or identified until children begin school. Even when poor academic performance is recognized, it may take expert assessment to distinguish mild intellectual disability from specific learning disability or emotional/behavioral disorders. People with mild ID are capable of learning reading and mathematics skills to approximately the level of a typical child aged nine to twelve. They can learn self-care and practical skills, such as cooking or using the local mass transit system. As individuals with intellectual disability reach adulthood, many learn to live independently and maintain gainful employment.

Moderate ID (IQ 35–49) is nearly always apparent within the first years of life. Speech delays are particularly common signs of moderate ID. People with moderate intellectual disability need considerable supports in school, at home, and in the community in order to fully participate. While their academic potential is limited, they can learn simple health and safety skills and to participate in simple activities. 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. As adults, they may work in a sheltered workshop.

People with severe or profound ID need more intensive support and supervision their entire lives. They may learn some ADLs, but an intellectual disability is considered severe or profound when individuals are unable to independently care for themselves without ongoing significant assistance from a caregiver throughout adulthood. Individuals with profound ID are completely dependent on others for all ADLs and to maintain their physical health and safety, although they may be able to learn to participate in some of these activities to limited degree.

Causes:

Psychological services – Wever, doctors have found many other causes. The most common are:

Genetic conditions. Sometimes disability is caused by abnormal genes inherited from parents, errors when genes combine, or other reasons. The most prevalent genetic conditions include Down syndrome, Klinefelter syndrome( little or no protein production/ common among boys), neurofibromatosis (tumors form in nerve tissue), congenital hypothyroidism, William syndrome (Cardiovascular problem/specific facial features), phenulketonuria – PKU (doesn’t produce enzyme to breakdown phenylalanine), and prader-Willi syndrome(genetic disorder – constant hunger). Other genetic conditions include Phelan-McDermid syndrome Problems during pregnancy. Intellectual disability can result when the fetus does not develop properly. For example, there may be a problem with the way the fetus’ cells divide as it grows. A pregnant person who drinks alcohol (see fetal alcohol spectrum disorder) or gets an infection like rubella during pregnancy may also have a baby with intellectual disability.

 Problems at birth: If a baby has problems during labour and birth, such as not getting enough oxygen, he or she may have developmental disability due to brain damage.

Exposure to certain types of disease or toxins: Diseases like whooping cough, measles, or meningitis can cause intellectual disability if medical care is delayed or inadequate. Exposure to poisons like lead or mercury may also affect mental ability.

Iodine deficiency, affecting approximately 2 billion people worldwide, is the leading preventable cause of intellectual disability in areas of the developing world where iodine deficiency is endemic. Iodine deficiency also causes goiter, an enlargement of the thyroid gland. More common than full-fledged cretinism, as intellectual disability caused by severe iodine deficiency is called, is mild impairment of intelligence. Certain areas of the world due to natural deficiency and governmental inaction are severely affected. India is the most notorious, with 500 million suffering from deficiency, 54 million from goiter, and 2 million from cretinism. Among other nations affected by iodine deficiency, China and Kazakhstan have instituted widespread salt iodization programs, whereas, as of 2006, Russia had not.

Malnutrition is a common cause of reduced intelligence in parts of the world affected by famine, such as Ethiopia.

Source : Psychological Matters Asia