PSY240: - L6

Reading §

• Explain the challenges of assessing the abilities of individuals with intellectual/developmental disorders
  • People with developmental disabilities may be given lower priority for services than others or excluded from medical and surgical interventions
  • Damage is manifested in a number of ways depending on the condition, including unusual physical features; particular types of cognitive, language, motor, or other deficits; and patterns of behaviour (e.g., hyperactivity, stereotypy, aggressiveness).
• Identify different ways that intellectual disabilities might be caused
  • Neurodevelopment disorders are associated with varying degrees of damage to the brain occurring at different stages of development before, during, or after birth
  • The etiology of neurodevelopmental disorders in general and intellectual disability in particular is complex. In some disorders, the cause is clearly genetic (e.g., chromosomal abnormality). Intellectual disabilities can also be caused by environmental factors at different stages of development (e.g., maternal malnutrition, toxins, or maternal infections; oxygen deprivation; prematurity; or birth-related trauma). The postnatal environment can also significantly affect development. Intervention strategies for people with intellectual disabilities tend to focus on developing social and community living skills and reducing or managing challenging behaviours. Pharmaceutical interventions for severe behavioural problems and mental health difficulties associated with dual diagnosis are recommended. Sex education, while controversial, can increase sexuality awareness and reduce the risk of abuse while promoting more successful integration into the community. Genetic and supportive counselling for family members and parent training can reduce family stress and improve quality of life for individuals with developmental disorders and their families.

Lecture §

• PDF:
• Prevalence What is the prevalence rate of Intellectual disability?
  • Vary to $1\%-3\%$ depending on classification system
• Symptom What are some (4) common symptoms of intellectual disability?
• Diagnosis: What are the 3 criteria that must be met for a diagnosis
  • Adaptive + IQ Test + Developmetal Period:
  • How is Intelligence measured (5 criteria)
  • Tests with 4 level of categorization
  • What are some issues with IQ measurement
    • Also reflect adaptive behaviour (not single targeted measurement)
    • Description of functioning level should be contextualized
    • Do not take into account sensory, motor, or language deficits
    • Individuals with intellectual disabilities typically have not received the type of exposure to test environments that other individuals have
  • What is adaptive behaviour and how it is been measured
    • Adaptive behaviour: encompasses conceptual, social, and practical abilities, including areas of communication; self-care; domestic, academic, social, or community leisure and work skills
    • Vineland Adaptive Behavior Scales Third Edition 2006
    • Evaluates the level of support needed
    • Adaptive Behavior Assessment System Third Edition
    • Scales of Independent Behavior-Revised
  • What are some interviewing issues related to diagnosis
    • Relatively good function -> Hide aspects of disorder
    • Cognitive and linguistic limitations, and social desirability may give way to acquiescence during an interview
    • Interviewing family members provides an additional perspective (potential bias)
• Etiology: Zigler’s Two-Group Appraoch
  • Organic group: a clear biological basis (severe and profound ID)
    • Genetic disorders
    • Chromosome abnormalities
      • Chromosomal Abnormalities: result of a structural alteration in the chromosome or due to a person having a greater or smaller number of chromosomes
      • Parental Screening
        • Chorionic villus sampling (CVS): obtaining cells from the placenta; complication about $2-5\%$
        • Amniocentesis: A small amount of amniotic fluid is withdrawn, and cells contained in the fluid are then cultured in the lab; accuracy $99.4\%$; complication about $0.5\%$
      • Down syndrome Type 1: trisomy 21 ($95\%$)
        • Children: delayed nonverbal cognitive development, deficits in verbal abilities and auditory short-term memory
    • Behavioural phenotypes
      • Behavioural phenotypes: the pattern of social, cognitive, and behavioural abnormalities
      • Environmental Factor
  • Cultural-familial group: no clear organic basis (mild ID)
    • Poverty: They are found more frequently within lower socio-economic groups, and commonly have at least one parent and possibly one or more siblings with developmental delays
• Etiology Genetic Based (Organic) ^edc6d1
  • $14\%$ of developmental disabilities has a genetic basis
  • What are the 3 types of genetic inheritance
    • Has $50\%$ of inheriting
    • Dominant inheritance: only 1 parent has it can pass on
      • Ex. Tuberous sclerosis and neurofibromatosis
    • Recessive inheritance: both parents need to carry for disorder to occur;
      • $25\%$ of inheritance; $50\%$ as a carrier but no symptom
      • Ex. phenylketonuria, TaySachs disease, and galactosemia
    • Sex-linked: carried in $X$ chromosome
      • Mostly linked with males with $50\%$ chance
      • Fragile X syndrome (described later in this chapter) and Lesch-Nyhan syndrome)
  • What are Metabolic Disorders and the cause and treatments
    • Phenylketonuria (PKU): n “inborn error of metabolism.”
    • No cure, but treatment can start early
    • Treatment: require a certain diet, so intellectual functioning will not be impaired
• Etiology Environmental Factors: Prenatal Environment ^eaffba
  • Drugs
    • Antidepressants, Opioids, Marijuana, Nicotine (Cigarette smoking, Second hand smoke, E-cigarettes), Alcohol
  • Pollutants
    • Toxic metals, synthetic hormones, plastic ingredients, pesticides, herbicides
    • Air and water pollution
    • Lead (dose–response relationship)
  • Teratogens
    • Individual differences in genetic susceptibility
    • Cumulative impact
    • Sleeper effects: long term incubation
    • Sensitive period
  • Maternal Infection
    • Rubella: during the first three months of pregnancy can lead to intellectual disability, visual defects, deafness, heart disease, and other problems
    • Infections, such as influenza may lead to Schizophrenia
    • HIV: HIV can be transmitted from mother to infant during pregnancy and delivery, or through breast milk
  • Fetal Alcohol Spectrum Disorder (FASD)
  • Maternal Emotional State
    • Can affect fetus’ behaviour, cognition, HPA AXIS, Autonomic System
  • Birth-related Causes
    • Extreme prematurity or a lack of oxygen during prolonged or complicated labour and delivery can result in developmental problems including visual deficits, cerebral palsy, and speech and learning difficulties
  • Age & Nutrition
    • Infant mortality rate high for teen mothers 15 years or younger
    • Women delaying pregnancies until their 30s or 40s risk infertility
    • General malnutrition of mother affects growth of fetal brain; later cognitive impairments
    • Spina bifida, neural tube defects
  • Do children inherit low intelligence from their parents, or do parents with low intelligence create a deprived environment?