Mental Retardation

Mental Retardation in child

Mental Retardation

One to three percent of the general population is mentally retarded. Mental retardation is defined as significantly sub average general intellectual functioning, associated with  significant deficit or impairment in adaptive functioning,which manifests during the developmental period (before 18 years of age.)

In this definition, general intellectual functioning means, the result of a standardized intelligence test(s); significantly sub average means to standard deviations below the mean (usually an IQof below70);while adaptive behavior is the person’s ability to meet the responsibilities of social, personal, occupational and interpersonal areas of life according to his or her age and socio-cultural and educational background.Adaptive behavior is measured by clinical interview and standardized assessment scales.

Very often, it is assumed that the mentally retarded persons constitute a homogenous group. This is not true. The mentally retarded persons vary in their behavioral, psychological, physical and social characteristics as much as normal general population does.

Another common error is taking the IQ score as the measure of intelligence. It should be remembered that a mentally retarded person must have a deficit in both general and intellectual functioning and adaptive behavior.

1. Mild Mental Retardation

This is the commonest type of mental retardation, accounting for 85-90%of all cases.The diagnosis is made usually later than in other types of mental retardation.

In the pre-school period (before 5 years of age), these children often develop like other normal children with very little deficit. Later, they often progress up to 6th class (grade) in school and can achieve vocational and social self-sufficiency with little support.Only under stressful conditions or in the presence of an associated disease, supervised care is needed.
This group has been referred to as ‘educable’ in aprevious educational classification of mental retardation.

2. Moderate Mental Retardation

About 10%of all mentally retarded have an IQ between 35-50. In the educational classification, this group was earlier called ‘trainable’ although many of these persons can also be educated.

In the early years, despite a poor social awareness, these children can learn to speak.Often, they drop out of school after 2nd class (grade). They can be trained to support themselves by performing semi-skilled or unskilled work under supervision. A mild stress may destabilize them from their adaptation, thus they work best in supervised occupational settings.

3. Severe Mental Retardation

Severe mental retardation is often recognized early in life with poor motor development (significantly delayed developmental milestones) and absent or marked ly delayed speech and they can be taught to talk.At best, they can perform simple tasks under close supervision. In the earlier educational classification, they were called ‘dependent’.

4. Profound Mental Retardation

This group accounts for 1-2%of all mentally retarded. The associated physical disorders which often contribute to mental retardation are common. The achievement of developmental milestones is markedly delayed.They often need nursing care or ‘life support’ under a carefully planned and structured environment like- group home.