Children with Disabilities

Nancy Peterson, Catherine Twomey, Mark Batshaw, Nancy Roizen, Louis Pellegrino, Mark Batshaw, Nancy Roizen, Louis Pellegrino

• Publisher: Brookes Publishing
• Year: 2019
• ISBN:
  9781681253213
• Edition: 8
• Topic: Social Sciences
• Subtopic: Disabilities in Sociology
• Index: Social Sciences

Explore what's new in the new edition!

Trusted for four decades by university faculty and relied on by thousands of professionals from diverse fields, Children with Disabilities is the gold-standard text on working effectively with children and families. Now this authoritative resource is in its eighth edition, enhanced with new chapters on critical topics, the latest evidence-based practices , updated instructor materials , and guidance on working with a wide range of professionals to address every aspect of child health and well-being.

Spearheaded by senior editor Mark Batshaw, M.D., Chief Academic Officer at Children's National Health System, this new edition is an unparalleled compendium of information about developmental, clinical, family, education, and intervention issues, from birth through adolescence. Every chapter has been meticulously peer-reviewed, and content has been updated throughout to reflect important new research and developments in diverse fields. Comprehensive coverage of contemporary issues makes this volume an indispensable reference for practicing professionals, and the student-friendly features and multimedia instructor materials make it the ultimate textbook for courses on disability.

A treasury of essential knowledge from a who's who of today's leading experts and innovators, Children with Disabilities is a cornerstone resource that professionals will use year after year to support their important work and ensure that every child and family thrives.

WHAT'S NEW

• Expanded focus on interdisciplinary care, including practical guidance on how professionals from different fields can effectively collaborate
• New chapters on key topics: sleep disorders, assessment of physical disabilities, the senses, rehabilitative services, interdisciplinary care, the role of medication, and the effect of health care disparities on child outcomes
• New Evidence-Based Practice boxes throughout the text, for easy review of recent studies and recommended practices
• Updated nomenclature based on new developments in the field and recommendations from respected organizations

STUDENT-FRIENDLY FEATURES: Students will benefit from chapter overviews, a helpful glossary, case studies that bring key concepts to life, thought questions, a test bank with more than 200 questions for faculty members, resource lists for further reading, and 200+ downloadable illustrations. And with the complete package of multimedia instructor materials, instructors will use this textbook effectively in their courses and prepare students for years of successful practice.

Explore what's new in the new edition!

Upon completion of this chapter, the reader will

Understand the definition of the term developmental delay and the implications of the terms mental retardation and intellectual disability

Be aware of the various causes of intellectual disability

Recognize the various interventions in intellectual disability

Be aware of the different levels of functioning and independence that individuals with intellectual disability can achieve

Intellectual disability refers to a heterogeneous group of disorders that have significant deficits in reasoning that impairs the individual’s ability to function in day to day life. People with intellectual disability have the capacity to learn, but they have difficulty adapting that knowledge to novel situations. There are many different causes of intellectual disability. Consequently, the range of the cognitive impairment seen in intellectual disability is wide and comorbid disorders are the rule. A multimodal, individualized approach to management can optimize the individual’s ability to participate in everyday life.

CASE STUDY

Daniel’s mother, Marina, noticed many signs in his early development that indicated atypical development. (In the following paragraphs, the typical ages for these developmental milestones are indicated in parentheses after the age at which Daniel achieved them).

As an infant, Daniel showed little interest in his environment and was not very alert. Although Marina tried to breastfeed him, his suck was weak, and he frequently regurgitated his formula. He was floppy and had poor head control. His cry was high pitched, and he was difficult to comfort. He would sit in an infant seat for hours without complaint.

In social and motor development, Daniel was delayed. With regard to his social development, Daniel smiled at 5 months (2 months) but was not very responsive to his parents’ attention. He did not start babbling until 13 months (6 months). With regard to gross motor development, Daniel could hold his head up at 4 months (1 month), roll over at 8 months (5 months), and sit up at 14 months (6 months). He transferred objects from one hand to the other at 14 months (5 months).

When evaluated with the Bayley Scales of Infant Development–Third Edition (BSID-III; Bayley, 2006) at 16 months of age, Daniel’s mental age was found to be 7 months and he received a mental developmental index (similar to an intelligence quotient [IQ] score) of less than 50. He progressed from an early intervention program to a special preschool program. Prior to school entry at age 6, Daniel was retested on the Stanford-Binet Intelligence Scales, Fifth Edition (SB5; Roid, 2003). His score indicated a mental age of 2 years and 8 months and an IQ score of 40. Concomitant impairments in adaptive behavior were demonstrated by the Vineland Adaptive Behavior Scales, Third Edition (Vineland-3; Sparrow, Chrichetti, & Saulnier, 2016), which revealed communicative, self-care, and social skill challenges.

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Thought Question:

How early can you determine that a child has intellectual disability, and why does it matter?

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DEFINING INTELLECTUAL DISABILITY

The term intellectual disability (ID) has replaced the older term mental retardation. This change was codified in federal legislation in 2010, when Rosa’s Law (Pub. L. 111-256) was enacted, which changed the term used in federal legislation from mental retardation to intellectual disability. The federal definition of the term itself did not change and comes from the Individuals with Disabilities Education Improvement Act (IDEA) of 2004 (PL 108–446), which defines intellectual disability as “significantly sub-average general intellectual functioning, existing concurrently with deficits in adaptive behavior and manifested during the developmental period that adversely affects a child’s educational performance.” Two other authoritative groups, the American Psychiatric Association (APA, 2013) and the American Association on Intellectual and Developmental Disabilities (AAIDD; Schalock et al., 2009) maintain the same three criteria of adaptive behavior deficits, subaverage intellectual function, and onset during the developmental period. Yet, their definitions shift the focus from IQ to adaptive behavior deficits. It is likely that the term intellectual disability will be replaced by the term intellectual developmental disorder. The latter has been proposed by the World Health Organization’s International Classification of Diseases (ICD-11) nomenclature as a health condition and is defined as “a group of developmental conditions characterized by a significant impairment of cognitive functions which are associated with limitations of learning, adaptive behavior and skills” (Bertelli, Munir, Harris, & Salvador-Carulla, 2016).

Adaptive Impairments

Individuals fulfilling the diagnosis of intellectual disability must demonstrate adaptive deficits that impair their ability to adapt to or function in daily life when compared with peers of similar age or culture. Indeed, it is the deficits in adaptive function that bring children to our attention. These impairments limit or restrict an individual’s participation and performance in one or more aspects of daily life activities, such as communication, social participation, function at school or work, or personal independence at home or in community settings. The limitations result in the need for ongoing support at home, school, work, or independent life. Typically, adaptive behavior is measured using individualized, standardized, culturally appropriate, and psychometrically sound tests (APA, 2013).

The AAIDD (Schalock et al., 2009) divides adaptive function into three domains: conceptual, practical, and socialization. Conceptual skills include such things as language and literacy, money, time, number concepts, and self-direction. Practical skills include the activities of daily living, occupational skills, health care, travel/transportation, schedules/routines, safety, use of money, and use of the telephone. Social skills encompass interpersonal skills, social responsibility, self-esteem, gullibility, naïveté, social problem-solving, and the ability to follow rules/obey laws and to avoid being victimized. The AAIDD definition of intellectual disability requires deficits to exist in one of the three domains of adaptive behavior.

Intellectual Functioning

There is general agreement that the definition of intellectual disability requires that a person must have significantly subaverage intellectual functioning and impairments in adaptive abilities with onset during the developmental period; however, disagreements over operationalizing this definition have arisen for both biological and philosophical reasons. The first controversial issue is that the definition involves the assessment of intellectual functioning. The average level of intellectual functioning in a population corresponds to the apex of a bell-shaped curve (Figure 14.1). Two standard deviations on either side of the mean encompass 95% of a population sample and approximately defines the range of typical intellectual functioning. By definition, the average IQ score is 100, and the standard deviation (a statistical measure of dispersion from the mean) of most IQ tests is 15 points. Historically, a person scoring more than 2 standard deviations below the mean, or below an IQ of 70, has been considered to have intellectual disability.

Statisticians, however, point out that there is a measurement variance of approximately 5 points in assessing IQ by most psychometric tests. In other words, repeated testing of the same individual will produce scores that vary by as much as 5 points (American Psychiatric Association, 2000). Using this schema, intellectual disability would be diagnosed in an individual with an IQ score between 70 and 75 who exhibits significant impairments in adaptive behavior, whereas it would not be diagnosed in an individual with an IQ of 65 to 70 who demonstrates adaptive skills in the typical range.

Figure 14.1. Bimodal distribution of intelligence. The mean IQ score is 100. An IQ score of less than 70, or 2 standard deviations below the mean, can indicate intellectual disability. The second, smaller curve takes into account individuals who have intellectual disability because of birth trauma, infection, inborn errors, or other organic causes. This explains why more individuals have severe to profound intellectual disability than are predicted by the familial curve alone. (From Zigler, E. [1967]. Familial mental retardation: A continuing dilemma. Science, 155, 292–298. http://www.aaas.org. Reprinted with permission from AAAS.)

Measured IQ may not be stable over time. Children may grow into or out of intellectual disability. Some young children may evidence a decelerating trajectory of intellectual growth and move into the diagnosis as adolescents. Alternatively, children may have an intellectual growth rate that accelerates over time and grow out of the diagnosis. Others develop sufficient adaptive behavior to no longer meet the criteria for intellectual disability.

In addition to changes in the individual, there appears to be a change in performance on IQ measures in a population. This phenomenon, known as the Flynn effect, holds that there is a relationship between the length of time that an instrument is in use and the individual’s score on that instrument. This is based on the observation that the mean IQ increased on every restandardization sample in a population for major intelligence tests (Schalock et al., 2009).

Cognitive functioning is not always uniform across all neurodevelopmental domains. An example is found in a study by Wang and Bellugi (1993), who compared neuropsychological testing results in children with Down syndrome and Williams syndrome. Although the full-scale IQ scores in both groups were similar, the pattern of cognitive strengths and weaknesses was very different. The individuals with Williams syndrome had much st...