chapter 5 new

What is Intellectual Developmental Disorder (IDD)?

A neurodevelopmental disorder involving deficits in intellectual functioning and adaptive functioning, with onset during the developmental period.

What are the 3 core features of IDD?

1) Deficits in intellectual functioning; 2) deficits in adaptive functioning; 3) onset during the developmental period.

Does a low IQ alone diagnose IDD?

No. DSM-5-TR emphasizes adaptive functioning as well as intellectual functioning.

What is intellectual functioning?

Reasoning, problem solving, planning, abstract thinking, judgment, academic learning, and learning from experience.

What is adaptive functioning?

How effectively a person meets community standards of personal independence and social responsibility for their age/cultural group.

What are the 3 domains of adaptive functioning?

Conceptual, social, and practical.

What does the conceptual domain of adaptive functioning include?

Communication, academic skills, and concepts.

What does the social domain of adaptive functioning include?

Interpersonal skills, social responsibility, social understanding, and judgment.

What does the practical domain of adaptive functioning include?

Self-care, everyday living, work, health/safety, and independence.

What does DSM-5-TR use to determine IDD severity?

Adaptive functioning and the level of support needed, rather than IQ alone.

What are the 4 levels of IDD severity?

Mild, moderate, severe, and profound.

What was traditionally used as an IQ guideline for IDD?

Approximately 2 standard deviations below the mean.

What is the estimated prevalence of IDD?

About 1%–3% of the general population.

What is the sex ratio for mild IDD?

About 1.6 males for every 1 female.

Which level of IDD is by far the most common?

Mild IDD.

About what percentage of people with IDD have mild IDD?

Up to about 85%.

Why can IQ test scores differ between children?

Factors such as socioeconomic conditions, culture, education, nutrition, health, and environmental opportunities can affect performance.

What is redlining?

A historical practice of systematically restricting access to housing, resources, and opportunities in certain racial/ethnic communities, contributing to environmental and socioeconomic disparities.

How can socioeconomic disadvantage affect intellectual development?

Poverty, inadequate child care, poor nutrition, environmental deprivation, and limited educational opportunities can negatively affect development.

How do children with IDD generally progress through developmental stages?

They follow the same general sequence as typically developing children, but development is slower and skills may emerge at different ages.

Should a child's chronological age or developmental age guide expectations?

Developmental age should guide expectations and teaching methods.

Example of developmental age vs chronological age

A 7-year-old with mild IDD may function at a developmental level comparable to a typically developing 4-year-old in some areas.

Can adaptive skills improve over time in IDD?

Yes. They may improve, especially with appropriate training, opportunities, education, and support.

What are common concerns in IDD?

Speech/language problems, behavioral challenges, emotional difficulties, and other physical/developmental disabilities.

How common are major emotional difficulties in children with mild IDD?

About 1/3 of children with mild IDD showed major signs of emotional difficulties in the Rutter et al. study.

How common are major emotional difficulties in children with more severe IDD?

About 1/2 showed major signs of emotional difficulties in the Rutter et al. study.

How much higher are behavioral challenges in children with IDD?

About 3–5 times higher than in typically developing children.

Are children with IDD more likely to have other physical/developmental disabilities?

Yes, including cerebral palsy, epilepsy, and emotional/behavioral disorders.

What is the prevalence of epilepsy among children with intellectual disabilities?

About 22 per 100 children.

What is the prevalence of cerebral palsy among children with intellectual disabilities?

About 20 per 100 children.

What is the prevalence of anxiety disorder among children with intellectual disabilities?

About 17 per 100 children.

What is the prevalence of oppositional defiant disorder among children with intellectual disabilities?

About 12 per 100 children.

What is the prevalence of Down syndrome among children with intellectual disabilities?

About 11 per 100 children.

What is the prevalence of autistic disorder among children with intellectual disabilities?

About 10 per 100 children.

What source was used for Figure 5.2 chronic health conditions?

Oeseburg et al. (2011).

What does Figure 5.2 show?

The prevalence per 100 children of several chronic health/developmental conditions among children with intellectual disabilities.

How many genetic disorders are associated with IDD?

Over 1,000 genetic disorders are associated with IDD.

What are the 2 broad groups of causes of IDD?

Organic/biological causes and cultural-familial/nonorganic causes.

What proportion of moderate-to-profound IDD has a known genetic or environmental cause?

Almost 2/3.

What proportion of mild IDD has a known cause?

Only about 1/4.

What is the cultural-familial group?

A group in which environmental and situational factors such as poverty, inadequate child care, poor nutrition, and parental psychopathology are important contributors.

What proportion of people with IDD does the cultural-familial group comprise?

About 1/2 to 2/3 of people with IDD.

What are examples of organic causes of IDD?

Chromosome abnormalities, genetic disorders, prenatal toxic exposure, brain injury, and other biological conditions.

What is Down syndrome?

A genetic/chromosomal condition and the most common disorder resulting from a chromosome abnormality.

What is Fragile-X syndrome?

A genetic disorder and a major inherited cause of IDD.

What is the approximate prevalence of Fragile-X syndrome in males?

About 1 in 4,000 males.

What is the approximate prevalence of Fragile-X syndrome in females?

About 1 in 8,000 females.

What percentage of males with the FMR-1 gene may transmit the disorder without being affected themselves?

About 20%.

What behaviors can occur with Fragile-X syndrome?

Shyness, poor eye contact, social anxiety/avoidance, communication delays, repetitive behaviors, and autism-like behaviors.

What percentage of males with Fragile-X show some autism-spectrum-like behaviors?

Most affected males.

What percentage of females with Fragile-X show some autism-spectrum-like behaviors?

About 1/3.

How many children with Fragile-X meet criteria for ASD?

Close to 1/2.

What is Prader-Willi syndrome?

A genetic disorder involving short stature, IDD/learning disabilities, incomplete sexual development, low muscle tone, and an involuntary urge to eat constantly.

How common is Prader-Willi syndrome?

About 5–10 per 100,000 births.

At what age can extreme overeating, foraging, and hoarding develop in Prader-Willi syndrome?

Around ages 2–6.

What are examples of environmental/nonorganic risk factors for IDD?

Poverty, poor nutrition, inadequate child care, environmental deprivation, and parental psychopathology.

What is the heritability of intelligence according to the textbook?

Approximately 50%; both genetic and environmental factors contribute.

What is the two-group approach to causes of IDD?

Distinguishing organic/biological causes from cultural-familial/nonorganic causes.

What is the relationship between IDD and socioeconomic status?

IDD is more prevalent among children experiencing socioeconomic disadvantage, although this does not mean socioeconomic status itself is a single cause.

What did the textbook report about an initial Black-White IQ difference?

An initial difference of over 17 points was discussed, with socioeconomic and environmental factors accounting for much of the difference; it should not be interpreted as an inherent racial difference.

What are some intervention principles for IDD?

Begin intervention early, match instruction to developmental level, teach adaptive skills, involve families, and provide educational/social supports.

When are intervention efforts generally most effective for IDD?

When they begin early and are matched to the child's developmental and adaptive needs.

What is the main goal of intervention for IDD?

Improve functioning, independence, adaptive skills, and quality of life while supporting the child's family and environment.