Mental Retardation

Mental Retardation (MR) refers to reduction in intelligence of an individual which is either innate or occurs during his period of development along with difficulties in carrying out activities of daily living.

It is most common developmental disorder affecting general intelligence quotient with additional problems such as speech, ambulation, seizures, vision, non responsiveness to physical contact, reduced alertness or spontaneous play, feeding, also presence of associated conditions like heart disease, anemia, dental problems, obesity are found.

Mental retardation is the most commonly seen disability, of the developmental disabilities and affects between 8% and 3% of the population. Physicians identify four degrees of mental retardation based on IQ and adaptive behavior.
Boys are more prone to MR by a ratio of 2.2:1.
It may be difficult to assess very young children for Mental Retardation, so most clinicians will not give a definitive diagnosis of mental retardation to children under the age of two unless their symptoms are extremely severe and/or they have a condition that is highly associated with this disorder(such as Down’s Syndrome etc) or markedly delayed developmental milestones. Often, particularly with mild or moderate mental retardation, it is not until children have difficulties in school that symptoms are recognized.
These individuals are typically diagnosed before the age of 18 years old.

Mental Retardation is a condition which is caused not only by biological factors but also by psychosocial factors. In more than one third of cases, no cause can be found despite an extensive search.
Genetic causes:
Chromosomal abnormalities: down”s syndrome, fragile X,
Inborn error of metabolism: galactosemia, lesch nyhan syndrome.
Single gene disorder: neurofibromatosis
Cranial anomalies: microcephaly, macrocephaly, hydrocephaly.
Perinatal causes:
Birth trauma
Intra uterine growth retardation
Placental abnormalities
Drugs during first trimester
Acquired physical disorders in childhood
Infections commonest is encephalopathies
Cerebral palsy
Sociocultural causes.
Deprivation of sociocultural stimulation.
Psychiatric disorders: like PDD


Mental retardation is classified as: mild, moderate, severe and profound. The labels are highly general and may not always reflect the functional abilities of the person in different environments.
Individuals with mild cognitive impairment have an IQ range between 55-70. Characteristics include the ability to learn information at the third to seventh grade levels. These persons eventually can live in the community with occasional support. Individuals with moderate cognitive impairment have an IQ range between 40-55. Characteristics include the ability to learn information up to the second grade. These persons usually require support to function in the community. These individuals work well in sheltered workshops and group homes. Individuals with severe cognitive impairment have an IQ range between 25-40.These individuals may learn to talk during childhood and develop basic self care skills. In adulthood they are usually able to complete simple tasks with close supervision.

IQ Score Level of Mental Retardation
50-69 Mild Mental Retardation
36-49 Moderate Mental Retardation
20-34 Severe Mental Retardation
Below 20 Profound Mental Retardation



Failure to meet intellectual developmental markers
Failure to meet developmental milestones such as sitting, crawling, walking, or talking, in a timely manner
Persistence of childlike behavior, possibly demonstrated in speaking style, or by a failure to understand social rules or consequences of behaviors
Lack of curiosity and difficulty solving problems
Decreased learning ability and ability to think logically
Trouble remembering things
An inability to meet educational demands required by school

i. Mild mental retardation
In the Pre-school period(before 5years of age),these children often develop like other normal children with very little deficit. Later, they progress up to 6th class(grade) in school and can achieve vocational and social self-sufficiency with a little support. Only under stressful conditions or in the presence of an associated disease, supervised care is needed. This group is referred to as “Educable”
ii. Moderate mental retardation
In the early years despite poor social awareness, these children can learn to speak. Often they drop out of school after the 2nd class(grade).a mild stress may destabilize them from their adaptation. Thus they work best in supervised occupational settings. This group is referred to as “trainable”
iii. Severe mental retardation
Recognized early in life with poor motor development (significantly delay developmental milestones) and absent or delayed speech and communication. They can perform simple tasks under close supervision. This group is referred to as “dependent”
iv. Profound mental retardation
Achievement of developmental milestones is markedly delayed .They often need nursing care or life support under a carefully planned and structured environment like group homes and asylum.

Mental retardation with cerebral palsy
Mental retardation with down”s syndrome
Mental retardation with fragile X syndrome
Mental retardation with seizure disorder

1. Final destination of mentally retarded person is mental asylum?
DR SUMIT (OCCUPATIONAL THERAPIST): No not at all, and it should not be, every person has a right to spend ample amount of time in society.
2. Is IQ test reliable to comment on person”s ability?
DR. SUMIT (OCCUPATIONAL THERAPIST): Yes! Most of the time the IQ test judges the persons intelligence, but it depends on Experience and practical knowledge of the person who is testing.
Most of the time the child may not be able to perform up to his mark during examination.
If the child is uncooperative then the parent”s interview is taken under consideration, and most of the time if the parents are uneducated then score suffers.
Generally it has been said that the basic IQ of the person cannot be changed, but it definitely does not mean that IQ cannot be worked upon. In a proper learning program using sensory integration and other treatment modalities, the brain”s adaptive capacity can be improved.

Mental retardation is a manifestation with certain underlying cause, and this cause occurs early whereas MR is recognized late so as soon as the cause is detected by medical professional immediately the child should be sent for early intervention.
Mental retardation is mostly diagnosed when the child fails to meet with certain basic physical, mental, social, criteria, and this mostly happens when the child is above 3 years of age. After which an early intervention becomes a challenge to meet with his/her age appropriate standards.

“Empathy is the best approach while working with special child, the child should be treated with approach which gives him opportunity to adapt the environment, should be presented with enough responsibilities which will help the child to boost his confidence. At the same time if a wrong behavior is seen then rather than neglecting sympathetically it should be dealt with properly.”