Mental retardation is a developmental disability that first appears in children under

the age of 18. It is defined as an intellectual functioning level

 that is well below average and significant.

limitations in daily living skills. Mental retardation begins in

childhood or adolescence before the age of 18. In most cases, it persists throughout

adulthood. A diagnosis of mental retardation is made if an individual has an intellectual

functioning level well below average and significant limitations in two or more adaptive

skill areas. Intellectual functioning level is defined by standardized tests that measure

the ability to reason in terms of mental age)

 Mental retardation is defined as IQ score below 70-75. Adaptive skills are the skills needed for daily life. Such skills include the ability to produce and understand language

(communication); home-living skills; use of community resources; health, safety, leisure,

self-care, and social skills; self-direction; functional academic skills (reading, writing,

and arithmetic); and work skills.

  • Mild mental retardation:

Approximately 85% of the mentally retarded

population is in the mildly retarded category. Their IQ score ranges from

50-75, and they can often acquire academic skills up to the 6th grade level.

They can become self-sufficient and in some cases live independently, with

community and social support.

  • Moderate mental retardation:

About 10% of the mentally retarded population

is considered moderately retarded. Moderately retarded individuals have IQ

scores ranging from 35-55. They can carry out work and self-care tasks with

moderate supervision. They typically acquire communication skills in childhood

and are able to live and function successfully within the community in a supervised

environment such as a group home.

  • Causes of Mental Retardation


The severity of the symptoms and the age at which they first appear depend on the

cause. Children who are mentally retarded reach developmental milestones significantly

later than expected, if at all. If retardation is caused by chromosomal or other genetic

disorders, it is often apparent from infancy. If retardation is caused by childhood

illnesses or injuries, learning and adaptive skills that were once easy may suddenly

become difficult or impossible to master.

  • Factors of Mental Retardation :
  • Environmental factors:

Ignored or neglected infants who are not provided the

mental and physical stimulation required for normal development may suffer irreversible

learning impairments. Children who live in poverty and suffer from malnutrition,

unhealthy living conditions, and improper or inadequate medical care are at a higher

risk. Exposure to lead can also cause mental retardation. Many children have

developed lead poisoning by eating the flaking lead-based paint often found in older


  • Treatment:

If mental retardation is suspected, a comprehensive physical examination

and medical history should be done immediately to discover any organic cause of

symptoms. Conditions such as hyperthyroidism and PKU are treatable. If these

conditions are discovered early, the progression of retardation can be stopped and,

in some cases, partially reversed. If a neurological cause such as brain injury is

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