According
to the American
Association on Mental Retardation (AAMR), an individual is
considered to have mental retardation based on the following three
criteria:
Intellectual
functioning level (IQ) is below 70-75.
Significant limitations exist in two or more adaptive skill
areas and the condition is present from childhood (defined as
age 18 or less.).
The person's intellectual functioning is markedly below average
(IQ of 70 or less on a standard, individually administered test).
In 2 or more of the following areas, the patient has more trouble
functioning than would be expected for age and cultural group:
Communication
Self-care
Home living
Social and interpersonal skills
Using community resources
Self-direction
Academic ability
Work
Free time
Health
Safety
Starts before age 18.
Associated
Features:
Under developed
motor skills
Under developed language skills
Under developed self-help skills
Developing at a far slower rate than the child's peers.
Differential
Diagnosis:
Some disorders have similar or even the same symptoms. The clinician,
therefore, in his/her diagnostic attempt, has to differentiate
against the following disorders which need to be ruled out to
establish a precise diagnosis.
None Detailed
Causes
Mental retardation can be caused by any condition which impairs
development of the brain before birth, during birth, or in the
childhood years. Several hundred causes have been discovered,
but in about one-third of the people affected, the cause remains
unknown. The three major known causes of mental retardation are
the genetic conditions of Down Syndrome,
Fragile
X, and Fetal
Alcohol Syndrome, the result of alcohol consumption during
pregnancy.