Intellectual disability is one of the most common disabilities affecting approximately 3% of people.   This disability relates directly to the person’s intellectual and functional abilities. The degree to which someone is intellectually disabled is generally referred to as either:  mild, moderate, severe or profound.    The men, women and children who find sanctuary with Oasis Association fall into the last three categories, with an incidence of only 4 in 1000 people.  They need ongoing care and supervision.

People are diagnosed as being intellectually disabled when they

• have a below average level of intellectual functioning with an IQ of less than 70;
• experience two or more difficulties with skills of daily living such as personal hygiene, catching a bus, recognition of risk, self direction, etc
• the onset occurs before the age of 18 years
  (Source: Western Cape Forum for Intellectual Disability)

Causes
Intellectual impairment is caused by underdevelopment of, or damage to, the brain at different stages of the person’s development. These stages are referred to as:

1. Pre-natal;
2. Perinatal and postnatal
3. Childhood
4. Idiopathic

1. Pre-natal impairment can occur
   · at conception because of chromosomal abnormalities (for example Down Syndrome);
   · during pregnancy (eg infectious diseases);
   · due to drugs (eg fetal alcohol syndrome)
   · due to poor nutrition ;
   · and from failed abortion.
    
2. Peri and postnatal
   · Complications arising from the delivery of a pre term infant
   · brain damage from a complicated labour ;
   · inadequate oxygen;
   · trauma caused by instruments used during birth.
    
3. Childhood incidents and conditions include
   · head injuries (eg motor  vehicle accidents);
   · disease and illness (eg  meningitis or very high fevers);
   · poisoning;
   · malnutrition.
    
4. Idiopathic
   · This is when the cause is unknown and occurs in 25% of cases

Categories of intellectual disability
Intellectual disability is often determined by intelligence tests which, briefly, measure the cognitive developmental level in relation to the chronological age thus arriving at a “mental age”.  In the case of people with intellectual disability mental age is always considerably lower than chronological age. Intellectual disability is normally categorised as being mild, moderate, severe or profound. *

These are categorised accordingly: