Chapter 15Mental Retardation and Pervasive
Developmental Disorders
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Brief Overview
Mental retardation– pejorative overtones– changing societal views
Pervasive developmental disorders– severe communication & social deficits – much less common
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Overview: Mental Retardation
diverse category & wide range of symptoms
early intervention important
CASE STUDY: “A Mother With Mild Mental Retardation”– generally happy life– depression– does Karen have a “disorder”?
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Mental Retardation: definition
AAMR:
“Mental retardation is a disability characterized by significant limitations both in intellectual functioning and in adaptive behaviour as expressed in conceptual, social, and practical skills…”
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Symptoms & Features
significant intellectual limitations
significant limitations in adaptation
onset before age 18
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The Controversial IQ Test
cultural fairness
validity issues
what is it measuring?
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Limits in Adaptive Skills
conceptual– level of self-sufficiency
social– level of interpersonal skills
practical– daily living
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Historical Perspective
Pejorative terms idiot, moron, imbecile entered the psychiatric lexicon
1866: Langdon Down describes “mongolism”
1872: “asylum for idiots” in Ontario IQ test development
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Contemporary Perspective
classification based on:– IQ score– etiology
sub-types based on IQ score
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DSM-IV-TR: Severity of Mental Retardation
Mild – IQ 50-55 to 70
Moderate– IQ 35-40 to 50-55– e.g., Down syndrome
Severe– IQ 20-25 to 35-40
Profound– IQ below 20-25
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Epidemiology
1% of general populationdiffers according to “population” being
examineddisproportionate among low SES
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Etiology: Biological Factors
chromosomal disorders (e.g., Down Syndrome)
genetic disorders (e.g., phenylketonuria) infectious diseases (e.g., Rubella,
syphilis) Toxins (e.g., FAS) normal genetic variation
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Etiology: Psychological Factors
early sensory deprivationearly abuse/neglect
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Etiology: Social Factors
poverty and related under-stimulation
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Treatment: Prevention Efforts
A. Primary Prevention
health care promotion pregnancy testing: amniocentesis &
ultrasound
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Canadian Focus:Eugenics Movement
forced sterilization program (1928-72)– often done surreptitiously– Alberta & BC
lawsuits in the 1990s Alberta government apology
Discussion Point: How could this happen in Canada?
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Treatment: Prevention Efforts
B. Secondary Prevention
early intervention programs (e.g., Aboriginal Head Start in Canada)
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Treatment: Prevention Efforts
C. Tertiary Prevention
early assessment early education/skill development
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Treatment: Normalization Efforts
Mainstreaming
Deinstitutionalization
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Overview: Autistic Disorder & Pervasive Developmental Disorders (PDDs)
unusual problems emerging early in lifeprofound interpersonal disturbancesunusual behaviourscommunication problemsautism example: Rain Man
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Case Study: John’s Autism
apathetic to othersnegative reactions to affectionintensive behavioural intervention
planned
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Symptoms & Associated Features
impaired social interaction– lacking theory of mind/perspective-taking– social isolation
communication deficits– echolalia– pronoun reversal– often mute
stereotyped behaviour– self-stimulation
self-injury
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Savant performance
some children with Autism/PDD show exceptional ability in 1 domain– music, mathematics
rare & poorly understood
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Historical Perspective
“early infantile autism” (Kanner, 1943)
Asperger’s Syndrome childhood schizophrenia
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Epidemiology
Prevalence: 10/10,000 kids may have Autism (Bryson, 1996)
SES: little relation
gender: 3-4X more common in boys
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Etiology
Psychological/Social– little support despite traditional “blame the
parents” notion
Biological– consequence of other conditions (e.g., rubella)– genetics:
Concordance rates in twin study: MZ: 60%, DZ: 0%
– neurophysiology: endorphins