MENTAL RETARDATION

Presented by:Mrs. Shalini ChhabraSenior LecturerDepartment of PsychologyD.A.V. College for GirlsYamunaNagar

Definition and its meaning:The American Psychiatric Association (1994) in DSM IV defines Mental Retardation as “significantly sub average general intellectual functioning…that is accompanied by significant limitations in adaptive functioning”in certain skill areas such as self care, work, health and safety.

To qualify diagnosis, these problem must have begin before the age of 18.Mental retardation is defined in terms of level of performance as well as intelligence.The definition does not say anything about casual factors which can be primarily biological, psychosocial, socio cultural or a combination of these.Any functional equivalent of mental retardation that has its onset after age

17 must be considered dementia rather than mental retardation.Mental retardation is coded on Axis II of DSM IV along with personality disorder.It has been treated as a specific type of disorder although it may occur in combination with other disorder appearing in either Axis I or Axis II.Other psychiatric disorders especially

psychoses occur at markedly higher rate among retarded people than in general population. (Sturmey and Sevin, 1993, Borthwick- Duffy,1994).Mental retardation occur among children throughout the world.In its severe form,it is a source of great hardship to parents as well as an economic and social burden on a community.The prevalence rate of diagnosed

mental retardation in the United States is estimated to be about 1 percent , i.e., 2.6 million people, however, prevalence is extremely difficult to pin down precisely because definitions of mental retardation vary considerably (Roeleveld, et al.,1997).

Diagnostic features:1.Essential feature of mental retardation is significantly sub average general intellectual functioning. General

intellectual functioning is defined by the intelligence quotient, obtained by assessment with one or more of the standardized, individually administered intelligence tests. Sub average intellectual functioning is defined as an IQ of about 70 or below. Mental retardation would not be diagnosed in an individual with an IQ lower than 70 if there are no significant deficits or impairments in adaptive functioning.2.Sub average intellectual functioning is

accompanied by significant limitations in adaptive functioning in at least two of the following skill areas. Communication, self care, home living, social and interpersonal skills,use of community resources, self direction, functional academic skills work, leisure, health and safety. Impairment in adaptive functioning, rather than a low IQ, are usually the important symptoms in individuals with mental retardation.3.Adaptive functioning refers to how

effectively individuals cope with common life demands and how will they meet the standards of personal independence, expected of someone in their particular age group, socio cultural background and community setting.4.The onset must occur before age 18.

Levels of Mental Retardation:The DSM IV recognizes four degrees of severity of mental retardation. These are

indicated below in Table, together with their corresponding IQ Ranges.Retardation Severity and IQ RangesDiagnosed level of Diagnosed level of mentalmentalretardation.retardation.

Corresponding IQ RangeCorresponding IQ Range

Mild retardationMild retardation

Moderate retardationModerate retardation

Severe retardationSevere retardation

Profound retardationProfound retardation

50-55 to approximately 50-55 to approximately 707035-40 to 50-5535-40 to 50-55

20-25 to 35-4020-25 to 35-40

below 20-25below 20-25

It is important to remind ourselves once again that any classification system in the behavioural field will have strong features of both arbitrariness and pragmatism. The various levels of mental retardation as defined in DSM IV are described in greater detail.1.Mild mental retardation Mildly retarded individuals constitute by far the largest number of those

diagnosed as mentally retarded.People in this level are considered “educable”.They can often acquire academic skills up to 6th grade level.Their intellectual levels as adults are comparable with those of average 8 to 11 year old children.They may be able to perform intelligence test meant for 10 year old

but may not be comparable to the normal 10 year old in information processing ability and speed (Weiss et al., 1986).The social adjustment of such people often approximates that of adolescents, although they tend to lack normal adolescents’ imagination, inventiveness and judgement.Ordinarily, they don’t show signs of brain pathology or other physical anomalies but often they require some

measures of supervision because of their limited abilities to force the consequences of their actions.They have minimal impairment in sensorimotor areas and are often not distinguished from normal children until a later age.With early diagnoses, parental assistance, and special educational programs, the great majority of borderline and mildly retarded individuals

can adjust socially, master simple academic and occupational skills and become self supporting citizens(Maclean, 1997).They may need guidance under unusual social and economic stress.2.Moderate mental retardationModerately retarded individuals are likely to fall in the educational category of “trainable”.

They are to master certain routine skills, such as cooking or minor janitorial work, if provided specialized instruction in these activities.In adult life,they attain intellectual levels similar to those of average four to seven year old children.Although some can be taught to read and write a little and may manage to achieve a fair command of spoken language, their level of conceptualizing

extremely limited.Physically, they usually appear clumsy and ungainly. They suffer from bodily deformities and poor motor co-ordination.Some of them are hostile and aggressive; more typically they present an affable, unthreatening personality picture.Very rarely, extraordinary specialized skills such as outstanding musical ability is found.

With early diagnosis, parental help and adequate opportunities for training, most of them can achieve partial independence in daily self care, acceptable behaviour and economic sustenance in a family or other sheltered environment.They need guidance even when under mild social or economic stress.3.Severe mental retardationThey are sometimes referred to as depended retarded.

This group constituents 3%-4% of individuals with mental retardation.Motor and speech development are severely retarded.Sensory and motor handicaps are common.They can develop limited levels of personal hygiene and self help skills, which somewhat lessen their dependence.But they are always dependent on

others for care.Many profit to some extent from training and can perform simple occupational tasks under supervision.Can develop self protection skills to a minimal useful level in controlled environment.They profit to only a limited extent from instructions in pre academic subjects such as familiarity with the alphabet and simple counting, but can

master skills such as learning sight reading of some “ survival words”.4.Profound mental retardationThe term life support retarded is sometimes used to refer to profoundly retarded individuals.Only 1-2% of the mentally retarded is classified as profoundly retarded.Most of these people are severely deficient in adaptive behaviour and

unable to master any but simplest tasks.Useful speech, if they develop at all, is rudimentary.Severe physical deformities, central nervous system pathology, and retarded growth are typical; convulsive seizures,mutism, deafness and other physical anomalies are also common.These individuals must remain in custodial care all their lives.

They tend to have poor health and low resistance to disease and thus a short life expectancy.Severe and profound cases of mental retardation can be readily diagnosed in infancy because of the presence of obvious physical malformations, grossly delayed development and other obvious symptoms of abnormality.Although these individuals have marked impairment of over all intellectual

functioning, they may have considerably more ability in some areas than in others.Despite their limitations, they can be loyal and affectionate. It is important to mention that until relatively recently, the American Psychiatric Association DSM IV and American Association on Mental Retardation(AAMR) generally agreed on definitions of mental retardation and specifications of levels or degrees of it.

In 1992, AAMR broke away from this tradition adopting.IQ 75 as the cut off point for the diagnosis of mental retardation.The system focuses on the capabilities of the retarded individual rather than on the limitations.Mention the intensity and patterns of support required. The four patterns are: intermittent support, limited support, extensive support and pervasive support.

To some extent, the AAMR classification mirrors the DSM IV classification. Intermittent support,e.g., is needed only occasionally, perhaps during lines of stress or crisis. It is the type of support typically required for most mildly retarded individuals. At the other end of spectrum, pervasive support, or life long, daily support for most adaptive areas, would be required for profoundly retarded individuals. On the other hand many

professionals have voiced criticism of the new AAMR proposed guidelines and view this divergence of approaches as unfortunate and as increasing the potential for disagreement and confusion in rendering the mental retardation diagnosis(Greenspan, 1997).

Causes of mental retardationIn about 35% of the cases the cause of mental retardation can not be found. 25% of mental retardation cases occur in

association with known organic brain pathology.

Biological and Environmental factors that can cause mental retardation are:Biological Causes1.Genetic-Chromosomal factors:Mental retardation tends to run in families. This tendency is particularly

true of mild retardation.Poverty and socio- cultural deprivation also tend to run in families and early exposure to these conditions hinders the growth of intellectual potential and functioning.Mental retardation stemming primarily from biological causes that can be classified into several clinical types.a) Down’s syndrome

Genetic and chromosomal factors play a much clearer role in the etiology of relatively infrequent but more severe type of mental retardation such as- Down’s Syndrome.Research data are quite consistent in showing that they have their greatest deficits in verbal and language related skills but relatively unimpaired in their appreciation of spatial relationships.b) Phenylketonuria

Single gene defect such as PKU- Phenylketonuria and other inborn errors of metabolism may also cause mental retardation if they are not found and treated early.Lacks a liver enzyme needed to break down phenylalanine, an amino acid found in many foods.If the amount of phenylalanine in the blood increases it eventually produces brain damage.

The main reason for this disorder it appears that both parents must carry the recessive genes.c) CretinismThis disorder occurs due to endocrine imbalances and thyroid deficiency. It can be due to lack of iodine in diet, birth injuries, infectious diseases e.g., measles, diphtheria, genetically determined enzyme defect.Early detection and correction of

thyroid deficiency can help.If infants are not treated in 1 year then they may have permanent impaired intelligence.d) Cranial AnomaliesMental retardation is associated with number of conditions that involve alterations in head size and shape and for which casual factors have not been definitely established(Maclean 1997). Some of the anomalies associated with

this are:i) Macrocephaly(Large headedness): Increase in the size and weight of

the brain. Enlargement of the skull Visual impairment Convulsions Neurological symptoms

ii) Microcephaly(small headedness): It refers to a type of mental retardation resulting from impaired development of the brain and a consequent failure of the cranium to attain normal size.Head rarely exceeds 17 inches.Short in statureCone shaped skullThey fall within moderate, severe and

profound categories of mental retardation but most show little language development.iii) Hydrocephalus: It is a relatively rare condition in which the accumulation of an abnormal amount of cerebrospinal fluid with in the cranium causes damage to the brain tissues and enlargement of the skull.The brain is either already enlarged at birth or begins to enlarge soon after.

The disorder can develop in infancy or early childhood due to the development of brain tumor, subdural hematoma, meningitis.Expansion of skull leads to intellectual impairment or loss of sight and hearing.2.Infection and Toxic AgentsMental retardation is associated with wide range of conditions due to infection. If a pregnant woman is infected with

(i)Syphilis (ii)HIV-I (iii)German measlesher child may suffer brain damage.A number of toxic agents such as carbon monoxide.Immunological agents such as anti- tetanus serum or typhoid vaccine.Excessive use of alcohol by the pregnant woman.Over dose of the drug

Smoking during pregnancy.Incompatibility in blood types of mother and fetus.High blood pressure(Hypertension) or blood poisoning(Toxemia).Traumatic brain injury.Childhood illness such as Hyperthyroidism, whooping cough, chickenpox, measles and Hib disease(a bacterial disease).

An infection of the membrane covering the brain(meningitis) or an inflammation of the brain itself(encephalitis). May cause brain damage and mental retardation.3.Prematurity and TraumaBabies born with a weight less than 5.5 poundsPhysical injuryDifficulties in labour due to malposition

of the fetus.Bleeding with in the brain.Hypoxia- lack of sufficient oxygen to the brain may cause brain damage and result in mental retardation.4.Ionizing RadiationRadiation may act directly on the fertilized ovum or may produce gene mutations in the sex cells of either or both parents, which in turn, may lead to

defective offspring.Sources of harmful radiation are high energy, X-rays, nuclear weapon testing and leakages at nuclear power plants.5.Malnutrition and other factorsDietary deficiencies in protein and other essential nutrients.Negative impact of malnutrition on mental development may be more in direct.

Other factors include intellectual level of parents, pathogenic family structures, poor physical and medical care, living and educational environment and lack of physical and mental stimulation. All these factors have their effect on the intellectual development of the child.

Diagnosis:A comprehensive physical examination and medical history should be done.

Conditions such as hyperthyroidism and PKU are treatable. If these conditions are discovered early.If a neurological cause such as brain injury is suspected, the child may be referred to a neurologist or neuro psychologist for testing.A complete medical, family, social and educational history is complied.Children are given intelligence tests.

The popular tests which are used are:Stanford Binet Intelligence Scale Wechsler Intelligence ScalesWechsler Pre School and Primary scale of IntelligenceKaufmann Assessment Battery for childrenFor infants- Bayley Scales of Infant Development may be used to assess motor, language & problem solving skills.

Interviews with parents or other care givers are used to assess the child’s daily living, muscle control, communication and social skills. The Woodcock Johnson Scales of Independent Behaviour and the Vineland Adaptive Behaviour Scale(VABS) are frequently used to test these skills.

Interventions & Management of Mental Retardation:Interventions for mentally retarded

children must be comprehensive, intensive and probably long term to show benefits.Comprehensive treatment programs for mental retardation involve biological, behavioural and socio-cultural interventions.

Behavioural Strategies:•Caregivers taught skills for enhancing the child’s positive behaviours and reducing negative behaviours.

•Desired behaviours modeled in incremental steps; rewards given to the child as he or she masters the skill.•Self-injurious behaviour extinguished.

Drug Therapies:•Neuroleptic medications to reduce aggressive and antisocial behaviour.•Antipsychotics to reduce aggression and self-injury.

•Antidepressant medications to reduce depression, improve sleep and reduce self-injury.

Socio-cultural programs:•Early intervention programs including comprehensive services addressing, physical, developmental, educational needs and training parents.•Mainstreaming children into regular classrooms.

•Group homes that provide comprehensive services to adults.•Institutionalization of children or adults with severe physical handicaps or behavioural problems. Thanks !