MENTAL RETARDATION DR SEDDIGH. Pre test Custodial MR ???? Severe MR ???? % Sex >>>>>> ???? Peer...
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Transcript of MENTAL RETARDATION DR SEDDIGH. Pre test Custodial MR ???? Severe MR ???? % Sex >>>>>> ???? Peer...
Pre test Custodial MR ???? Severe MR ???? % Sex >>>>>> ???? Peer bahavior ???? Intellectual disability ????
HISTORY Mental retardation recognized perhaps
longer than any other currently studied in psychology
Written documents from ancient Egypt made oblique reference to the condition as early as about 1500 BC was often viewed as part of mental illness
relatively common
Features of Mental RetardationDSM-IV Criteria
significantly subaverage IQ (<70) concurrent deficits or impairments in
adaptive functioning characteristics evident prior to age 18
Mental Retardation defined in the Diagnostic and Statistical
Manual of Mental Disorders-IV as: significantly subaverage intellectual functioning:
an IQ of approximately 70 or below concurrent deficits or impairments in present
adaptive functioning in at least two of the following areas:communication, self-care, home living, social/interpersonal skills, use of community resources, self-direction, functional academic skills, work, leisure, health, and safety; and
onset before age 18 years.
Describing and Classifying Mental Retardation
5 DSM-IV-TR severity classifications for mental retardation
Mild – IQ of 50-55 to about 70 (Educable) Moderate – IQ of 35-40 to 50-55 (Trainable) Severe – IQ of 20-25 to 35-40 (Custodial) Profound – IQ below 20 or 25 (Custodial) Unspecified – presumption of mental
retardation but intelligence not testable with standardized instruments
Mild Retardation Some 85% of all people with mental retardation
fall into the category of mild retardation (IQ 50–70) They are sometimes called “educably retarded”
because they can benefit from schooling typically not identified until elementary school years
People with mild retardation typically need assistance but can work in unskilled or semiskilled jobs Intellectual performance seems to improve with age
Mild Retardation Research has linked mild mental
retardation mainly to sociocultural and psychological causes, particularly: Poor and unstimulating environments Inadequate parent-child interactions Insufficient early learning experiences
Mild Retardation Although these factors seem to be the
leading causes of mild mental retardation, at least some biological factors may also be operating Studies have linked mothers’ moderate
drinking, drug use, or malnutrition during pregnancy to cases of mild retardation
Moderate, Severe, and Profound Retardation Approximately 10% of persons with mental
retardation function at a level of moderate retardation (IQ 35–49) They can care for themselves and benefit from
vocational training About 4% of persons with mental retardation
display severe retardation (IQ 20–34) They usually require careful supervision and
can perform only basic work tasks
Moderate, Severe, and Profound Retardation About 1% of persons with mental retardation
fall into the category of profound retardation (IQ below 20) With training they may learn or improve basic
skills but they need a very structured environment
Severe and profound levels of mental retardation often appear as part of larger syndromes that include severe physical handicaps
Prevalence 1-3% of population (depending on cutoff)
Slightly more males than females
More prevalent in lower SES and in minority groups, especially for mild MR; no differences for more severe levels
Developmental Course Often children with mental retardation experience
helplessness and frustration in their learning environments, which leads to low expectations and limited success
With appropriate training and opportunities, children who have mild mental retardation may develop good adaptive skills in other domains
Language and Social Development Expressive language development may be weak in children with
Down syndrome
Fewer signals of distress or desire for proximity with primary caregiver, which can influence attachment
Self-recognition often delayed, but positive
Problems in the development of self-other understanding
Deficits in social skills and social-cognitive ability; can lead to rejection by peers
Emotional and Behavioral Problems
Emotional and behavioral disturbances four times greater than the general population
Impulse control problems, anxiety problems, and mood problems common
ADHD-related symptoms also common
Pica and self-injurious behavior also common among those with severe and profound MR
Other Disabilities Associated with MR Can be associated with other pervasive
physical and developmental disabilities, including sensory impairments, cerebral palsy, and epilepsy
Chance of other disability increases as degree of intellectual impairment increases
Etiology The causes of mental retardation are many
and varied
In some cases, pathology of a physiological or biological nature can be identified
for as many as 30–40% of those with mental retardation, causation is unknown
Causes of MR•Genetic Causes (65%) Chromosomal defects;
Structural anomalies;Inborn errors of metabolism
• Intrauterine Risk Factors (15%) Asphyxia; Developmental defects; Malnutrition/ Intrauterine growth retardation Maternal infections or diseases; Maternal substance abuse
•Perinatal Risk Factors (10%):Anoxia; Birth trauma;Low birth weight;Prematurity
•Neonatal and Postnatal Causes (10%):Childhood infections and diseases; Environmental toxins; Severe malnutrition, Trauma
Causes of Mental Retardation Many organic causes have been discovered but majority of cases
cannot be explained, especially for mild mental retardation
The two-group approach: organic mental retardation- includes chromosome
abnormalities, single gene conditions, and neurobiological influences
cultural-familial mental retardation- includes family history of mental retardation, economic deprivation, inadequate child care, poor nutrition, and parental psychopathology
Causes of Mental Retardation (cont.)Inheritance and the Role of the Environment
heritability of intelligence is approximately 50%
prenatal influences may be mistaken for genetic when they are actually environmental
Genetic and Constitutional Factors chromosomal abnormalities are the most common cause of
severe MR Down syndrome due to an additional 21st chromosome Fragile-X syndrome, the most common cause of inherited MR,
is associated with the FMR-1 gene Prader-Willi and Angelman syndromes both associated with
abnormality of chromosome 15; believed to be spontaneous genetic birth defects occurring around the time of conception
inborn errors of metabolism (referred to as single-gene conditions) can result in syndromes such as PKU
Causes of Mental Retardation
Causes of Mental Retardation (cont.)Neurobiological influences
adverse biological conditions (e.g., malnutrition, exposure to toxins, Rubella, prenatal and perinatal stressors)
infections, traumas, and accidental poisonings during infancy and childhood
prenatal alcohol exposure can lead to a Fetal Alcohol Spectrum Disorder (FASD)
Social and Psychological influences deprivation of physical and emotional care and social
stimulation particularly influential
Genetic Factors Down syndrome
three types of Down syndrome, each resulting from a different type of chromosomal error. Nondisjunction
Translocation
Mosaicism
Mental Retardation: Trisomy 21
Distinctive facial features Mild MR Parental age Medical complications
Genetic Factors phenylketonuria (PKU), an inherited metabolic
disorder that occurs in about 1 of every 10,000 live births Affected infants lack the ability to process
phenylalanine, severely damages the central nervous system
Genetic Factors Maple syrup urine disease
Affected infants tend to excrete urine that has a distinctive odor of maple syrup
may cause severe intellectual impairment, although more often than not the condition is fatal
cause of this condition has been linked to metabolic deficiencies of three separate amino acids causing extreme CNS damage in the newborn
Untreated maple syrup urine disease is fatal; few untreated infants survive more than a few weeks
Genetic Factors Galactosemia involves difficulty in
carbohydrate (sugar) metabolism, rather than amino acid metabolism
Infants with galactosemia are unable to properly process certain sugar components in milk
Results are toxic damage to the infant’s liver, brain, and other tissues
Prevention, Education, Treatment Child’s overall adjustment is a function of parental
participation, family resources, social supports, level of intellectual deficit, temperament, and other specific deficits
Treatment involves a multi-component, integrated strategy that considers children’s needs within the context of their individual development, family and institutional setting, and community
Prenatal education and screening may prevent some cases of MR
Treatment of children with mental retardation
Three types of prenatal intervention Chromosomal analysis for Down
Syndrome or other genetic abnormalities may result decision to abort fetus
Treatment for Rh blood incompatibility between mother and fetus may prevent fetal damage.
Prenatal identification of a PKU problem may result in maternal dietary restrictions
Prevention, Education, Treatment (cont.)
Risk and protective factors affecting the psychological adjustment of intellectually disabled children
Prevention, Education, Treatment (cont.)Psychosocial treatments
intensive, child-focused, early intervention efforts are very promising (particularly for disadvantaged children)
optimal timing for intervention is in the preschool years behavioral techniques include shaping, modeling, graduated
guidance, and social skills training cognitive-behavioral techniques, such as self-instructional
training and metacognitive training family oriented interventions help families cope with the
demands of raising a child with MR
Postnatal Interventions Infant stimulation programs provide positive
developmental environment for very young children who are at risk because of prenatal or later environmental circumstances
Specific instruction for young children in language skills appears promising and probably should be implemented as early as possible
Inclusion of young children of school age in classrooms with non disabled peers
Continuous name shift “Mental Retardation” and “Learning
Disabilities” are outdated and unacceptable for users
“Intellectual Disabilities” adopted by IASSID / AAMR US President´s Commission DSM-IVTR 2005
Post test Custodial MR ???? Severe MR ???? % Sex >>>>>> ???? Peer bahavior ???? Intellectual disability ????