Family, Psychoeducational, Behavioral, Interpersonal, and Pharmacologic Interventions

The capacity to adapt to disability and assist others with disability may have an evolutionary origin. De Waal (1996) describes assistance to an injured group member among primates as evidence of altruistic behavior. Mother monkeys will provide additional care to compensate for injuries, and other members of the group may “babysit” injured infants, as do other young of the group. If the risk of predation is low and food is adequate, handicapped animals may live to adulthood. In human evolution, Berkson (1993) described an adult Neanderthal male with severe arm and head injuries that occurred at an early age. Apparently, this individual adapted to the injury by using his teeth to hold objects. Other conditions, such as disabling arthritis, were found in Neanderthals as well. Thus, individuals with minor or even significant impairments in primate and human societies before the evolution of modern humans, in some instances, received adaptive assistance from other members of the group. Drawing on these possible evolutionary origins of assistance to others in need, this chapter reviews the historical background of care for persons with intellectual disability and discusses environmental provisions and supports, education and skill development, normalization and self-determination, and interventions for those with co-occurring mental and behavioral disorders (psychotherapy, behavioral interventions, and psychopharmacologic treatments). The modern developmental approach to understanding learning and development began with Jean Itard, at the end of the eighteenth century. As a member of the medical staff at the Institute for Deaf Mutes in Paris, he considered the link between deafness and learning. Because of this background, he was asked to study a feral child discovered living alone in the wild in southern France. It was thought that this boy might approximate “man in the state of nature.” Because the child was mute, he entered a school for the deaf in Paris although he was not deaf. Pinel (1809), the leading psychiatrist of the time, proposed that the boy, named Victor, was not teachable. Yet Itard, during the next five years, sought to instruct Victor, using approaches established for deaf persons.

Genetics, Behavior, and Behavioral Phenotypes

Geneticists and specialists working with individuals with intellectual disability now recognize that genetic syndromes may have characteristic physical phenotypes and behavioral features that may be linked to a specific genetic syndrome. These patterns of behavior are referred to as behavioral phenotypes. This chapter utilizes a developmental perspective to provide a definition and characterization of behavioral phenotypes in neurodevelopmental disorders and to discuss etiology, methodologies to understand underlying mechanisms, and the natural history of the disorder. Neurogenetic disorders with behavioral phenotypes include (1) Down syndrome, (2) Velocardiofacial syndrome, (3) Smith-Magenis syndrome, (4) Turner syndrome, (5) Rett’s disorder, (6) Lesch-Nyhan syndrome, (7) Prader-Willi and Angelman syndromes, (8) fragile X syndrome, and (9) Williams syndrome. Each of these neurogenetic disorders involves a different genetic mechanism and provides a portal to understand neurodevelopment. A disorder that is environmentally induced, fetal alcohol syndrome, is also discussed and it, too, may provide a key to understanding aspects of the developing brain (Ikonomidou et al., 2000). The first description of behavior associated with an intellectual disability syndrome was by Down (1887). In describing the syndrome that bears his name, Down observed that “They have considerable powers of imitation, even bordering on being mimics. Their humorousness and a lively sense of the ridiculous often color their mimicry.” Later, he added: “Several patients who have been under my care have been wont to convert their pillow cases into surplices (vestments) and to imitate, in tone and gesture, the clergymen or chaplain which they have recently heard.” He also commented on personality traits, saying that “Another feature is their great obstinacy—they can only be guided by consummate tact.” Although these stereotypes were not confirmed in subsequent studies (Gath and Gumley, 1986; Gunn, Berry, and Andrews, 1981), the prospect of linking behavior and genetics was introduced in this first description of a neurogenetic disorder. Subsequent early clinical descriptions, such as that of tuberous sclerosis complex by Critchley and Earl (1932), identified peculiar, and severe, behavioral problems in children and adult with that condition.

Etiology and Assessment

Intellectual disability is a general term that describes intellectual capacity and adaptive functioning. There are many causes and many co-occurring conditions. To appreciate and respect the uniqueness of each individual and to choose appropriate interventions, it is critical that, if possible, the cause for intellectual disability be identified or the conditions that led to or sustain it be recognized. This chapter begins with an overview followed by an approach to understanding causation, a description of how etiology is determined, consideration of the neurobiological/environmental interface, a discussion of the evaluation process to determine causes and conditions related to diagnoses, and a discussion of risk factors. Intellectual disability is an intellectual, cognitive, and developmental disability that profoundly affects an individual’s functioning and adaptation to everyday life. Intellect refers to mental ability or capacity, the power of thought, and the ability to reason and solve problems. Mental capacity is distinguished from perception, emotions, and feelings. Intelligence refers to facility and quickness in understanding and problem solving. In intellectual disability, there is reduced mental capacity. Cognition refers to the use or handling of knowledge through mental activities associated with thinking, learning, and memory, which are necessary processes to acquire knowledge. In intellectual disability, there are cognitive disabilities that vary depending on the individual syndrome. The extent of intellectual disability varies among syndromes, and there may be variations within a syndrome. Both cognition and intellect are linked to cortical brain function. Intellectual disability is a developmental disability with onset during the developmental period. Thus, there are delays in meeting developmental mile stones in motor, fine motor, language, and psychosocial areas. Finally, there are difficulties in adaptive function and in the mastery of developmental tasks as a result of intellectual, cognitive, and developmental disabilities. A focus on the etiology of intellectual disability is needed for research, clinical, and administrative purposes. This chapter will review the multiple causes of intellectual disability, considering the interface between genetic, neurobiologic, and environmental factors and causation. It emphasizes the importance of a comprehensive evaluation and provides guidelines for conducting an evaluation. Associated mental, emotional, and behavioral disorders are discussed in chapter 6.

The Classification of Intellectual Disability

Although intellectual disability has been recognized since antiquity, interest in its classification did not develop until the nineteenth century, when it became apparent that intellectual disability is not one homogeneous category, as was previously thought, but has many causes. Moreover, it became apparent that intervention could be beneficial and that interventions might be tailored for specific disorders. Early authors prepared the way for modern efforts to differentiate specific conditions that differ in both etiology and pathology, yet all result in intellectual disability. Some attempts were misguided. J. Langdon Hayden Down, in his ethnic classification (1866; Jordan, 2000), sought to classify based on the physical appearance of the individuals he examined. His goal was to absolve parents of self-blame for the handicap by emphasizing a constitutional basis for their child’s disorder. He proposed an “ethnic classification,” suggesting that the various forms of intellectual disability represented regressions to stereotypical racial forms (e.g., mongoloid, Aztec). Although he later abandoned this unfortunate idea, he continues to be known for it. Still, he is credited with drawing scientific attention to the syndrome bearing his name (Jordan, 2000) and for suggesting that the best classification is one based on etiology. Subsequently, he anticipated current efforts at classification by describing three major groups: (1) congenital, which included microcephalic, macrocephalic, hydrocephalic, epileptic, and paralytic types; (2) developmental, with a vulnerability to mental breakdown with stress during a developmental crisis; and (3) accidental (caused by injury or illness). Later, William Weatherspoon Ireland (1877), in his textbook on intellectual disability, suggested 10 subdivisions. Among these are genetous (congential), microcephalic, epileptic, eclamptic, hydrocephalic, paralytic, traumatic, inflammatory, cretinism, and idiocy by social and physical deprivation. In 1880, tuberous sclerosis complex was identified by Désiré-Maglione Bourneville (1880), who established that intellectual disability might result from brain pathology. Subsequently, many other intellectual disability syndromes were recognized. Thus began a new era, with investigators searching for clearly defined disorders associated with intellectual disability; these were commonly named after their discoverers. It was an era when intellectual disability syndromes were beginning to be recognized, but medicine had little to offer therapeutically.

Introduction

The aim of this book is to provide professionals with the latest and most reliable information on intellectual disability and associated impairments. It utilizes a developmental perspective and reviews the various types of intellectual disability, discusses approaches to classification, diagnosis, and appropriate interventions, and provides information on resources that may offer additional help. The term “intellectual disability” is used throughout this book instead of “mental retardation” to reflect current perspectives. Intellectual disability refers to impairments in both cognitive functioning and adaptive skills whose onset is during the developmental period. It is a developmental, intellectual, and cognitive disability. Although the term “mental retardation” continues to be used in the International Classification of Diseases (ICD-10) and DSM-IVTR, the continued use of this designation has been questioned because it implies a static, unchanging condition rather than one that can change over time. Other terms, such as “mental handicap” and “learning disability,” have also been used. These variations in terminology are derived from long-standing concerns about the stigma of applying the term “mental retardation” to individuals. A more general term applied to individuals with intellectual disability is “mental disability.” The World Health Organization and the United Nations generally use the term “mental disability” as a broad descriptor, and the U.S. Supreme Court, in the Olmstead decision emphasizing the importance of community living, also used the term “mental disability.” The definition of “mental retardation” has changed nine times over the past 100 hundred years in the United States. Such changes in nomenclature come about with the acquisition of new knowledge regarding causes and efforts to preserve the dignity of persons who are intellectually disabled. Reflecting this new knowledge and concerns about the stigma sometimes associated with the term, on July 25, 2003, the name of the federal advisory committee, the President’s Committee on Mental Retardation (PCMR), was changed to the President’s Committee for People with Intellectual Disabilities (PCPID). Because the name designates the committee that advises the Secretary of Health and Human Services and the President on federal policy regarding programs and services, the change is noteworthy.

Ethics and Spirituality

This chapter considers ethical and spiritual issues related to intellectual disability. Consideration of the meaning of life of an intellectually disabled person must take into account how society defines and responds to individual differences. There are ethical and religious concerns regarding prenatal diagnosis and questions of how to teach ethical behavior to persons with intellectual disability. Participation in religious practices in the community and in group home settings is important for families and persons with intellectual disability. This chapter reviews these issues in detail. In biblical times, there were edicts about disability that offer insight into attitudes toward disabled people. There is an Old Testament injunction: “Thou shalt not curse the deaf, put a stumbling block before the blind, nor maketh the blind wander out of a path” (Leviticus 19:14). This may be the first Western command to legislate for the protection of the deaf and handicapped. Moreover, deaf persons without speech were viewed as children and provided the same protections as children. Yet, the threat of disability was also an element in biblical injunctions: “If you do not follow his commandments and decrees . . . all these curses will become upon you and overtake you: The Lord will afflict you with madness, blindness, and confusion of mind. At midday, you will grope around like a man in the dark” (Deuteronomy 28:15). Although help for those with disabilities was seen as a charitable obligation, disability was perceived potentially as a punishment from God. Ancient people often believed that illness was inflicted by a deity or supernatural power (Rosen, 1968). In records dating back before 2000 B.C., the birth of children with congenital impairments were used to predict the future of the community. In Babylonia, those who prophesized about the future kept a list of birth deformities and the specific meaning and prophecy that these disabilities foretold. Although a disability was viewed as a portent of things to come (Braddock and Parish, 2002) or punishment for immorality, there also existed the attitude that the disabled should be treated with compassion. The New Testament provides insight into how attitudes about disability evolved.

Epidemiology: Who Is Affected?

Intellectual disability is the most common developmental disorder and the most handicapping of the disorders beginning in childhood. It ranks as first among chronic conditions that limit full participation in society. Epidemiologic approaches provide a basis for understanding the distribution and dynamics of health, disease, and disorder for persons with intellectual disability; epidemiology is the foundation of public health practice. Because it relies largely on statistical methods, accurate data and clear definitions are essential. The interpretation of epidemiologic information requires background knowledge of demography, social sciences, environmental science, and the clinical sciences. Although epidemiologic studies are essential in establishing prevalence, and in describing the demography of a disorder, the role of epidemiology is far more extensive than this. Epidemiology can teach us about the nature and scope of intellectual disability and associated general medical, behavioral, emotional, and psychiatric problems. In so doing, epidemiologic approaches may be combined with neurobiologic and psychosocial measures. Moreover, epidemiologic studies can disclose individual developmental trajectories and the influences that shape those trajectories. Some of these influences promote risk; others provide protection and promote resiliency in the individual. Finally, experimental approaches in epidemiology allow the study of causative processes, factors that influence the course of the disorder, and service needs. It is these more extensive uses of epidemiology that are called for in future research. Chapter 3 outlines the classification of intellectual disability. This chapter will discuss the use of definitions of intellectual disability in establishing its prevalence, factors affecting prevalence, variability in rates in the various states, demographic features including the impact of increasing life expectancy, associated physical, behavioral, and emotional impairments, and new research directions. Accurate estimates of the number of intellectually disabled individuals are required for planning purposes and to gain better knowledge of the impact of interventions. Studies of the prevalence and incidence of intellectual disability date back to at least 1811, when Napoleon ordered a census of “cretins” to be made in one of the Swiss cantons (Kanner, 1964). Although little information is available about how this census was used, many surveys have been carried out since that time.

A Life Span Developmental Approach

Intellectual disability is a neurodevelopmental disorder that continues throughout the life span of the affected person. It is essential to understand how persons with intellectual disability progress throughout their life span from infancy to old age. The maturation of the brain, their environmental experiences, and the mastery of developmental challenges and tasks must all be considered. A focus on brain development is in keeping with neuroscience research indicating that progressive brain maturation is accompanied by successive synaptic reorganization as one moves from one developmental stage to the next. Anatomical Magnetic Resonance Imaging Studies are playing a major role in understanding the developmental trajectories of normal brain development (Durston et al., 2001; Giedd et al., 1999). Understanding the developmental trajectories of normal brain development is crucial to the interpretation of brain development in neurodevelopmental disabilities. During normal development, white matter volume increases with age, and although gray matter volumes increase during childhood, they decrease before adulthood. These changes in the brain are accompanied by changes in cognitive processing; for example, executive functioning shows a progressive emergence from the preschool years (Espy et al., 1999) into the adolescent years. Working memory and inhibitory processes may be measured during the preschool years. By adolescence, abstract reasoning, anticipatory planning, and mental judgment have emerged and may be measured. Cognitive abilities in adolescence are qualitatively different from those of young children as a result of the reorganization of the prefrontal cortex during maturation. How genetic background and environment interact in producing these changes is the object of ongoing study, yet investigators are beginning to understand how physiological processes of synaptic development, circuits, and neuronal network formation relate to processes of cognitive development (Fossella et al., 2003). The development of persons with intellectual disability is now being evaluated systematically, and developmental trajectories are being established for known neurogenetic syndromes. These studies are making up for a surprising lack of application of a developmental perspective to persons with intellectual disability. Developmental theorists have, for the most part, monitored and measured development in normally intelligent persons in establishing developmental landmarks.

Understanding and Evaluating Emotional and Behavioral Impairment

In English property law, intellectual disability and mental illness were differentiated in the thirteenth century. By 1690, John Locke’s An Essay Concerning Human Understanding had clarified differences between intellectual disability and mental illness. Locke wrote: . . . The defect in [intellectual disability] seems to proceed from want of quickness, activity, and motion in the intellectual faculties, whereby they are deprived of reason; whereas mad men seem to suffer by the other extreme. For they do not appear to me to have lost the faculty of reasoning: but having joined together some ideas very wrongly . . . they argue right from wrong principles. . . . But there are degrees of madness as folly; the disorderly jumbling of ideas together is in some more, and some less. In short, herein seems to lie the difference between [intellectually disabled] and mad men, that mad men put wrong ideas together, and so make wrong propositions, but argue and reason right from them: but [those with intellectual disability] make very few or no propositions, but argue and reason scarce at all. (Scheerenberger, 1983, p. 41) . . . Thus, Locke is often credited with establishing the dichotomy between mental illness and intellectual disability that influenced social policy for people with intellectual disability. But he did not appreciate the capacity persons with intellectual disability do have to reason with adequate supports, nor did he consider that persons with intellectual disability are also at risk for mental illness and behavior disorders. Historically, intellectual disability and mental illness were regarded to be mutually exclusive conditions. Affective and behavioral disturbances in individuals with intellectual disability generally were regarded as manifestations of maladaptive learning and adverse psychosocial experiences rather than as indications of a psychiatric disorder. This view has been shared by both intellectual disability and mental health professionals. Health professionals typically fail to consider the diagnosis of a psychiatric disorder among persons with intellectual disability despite the presence of signs and symptoms that would be readily ascribed as psychiatric disturbance among typically developing persons within the general population. This diagnostic bias may be an outgrowth of several factors.

Origins, Changing Concepts, and Legal Safeguards

When a health care professional becomes engaged in diagnosing and treating or supporting a person with intellectual disability, the complexities of the disorder become apparent. To provide the best care and the best support, knowledge about neurogenetic syndromes, management of biomedical and behavior features, psychosocial interventions, and the natural history of the disorder are critical. Background knowledge and sensitivity to the needs and life challenges of the affected person are especially important. With new knowledge in genetics, the neurosciences, and social sciences, and the utilization of the richness of family, school, and community resources for these individuals as they develop, the historical stigma of the diagnosis can be reduced and hopefully eliminated. Professionals, families, and community support personnel must join forces so that all available resources are fully utilized, thus allowing the person with intellectual disability to be appropriately treated for his condition and to begin to make choices and become a self-advocate to the extent possible. This chapter will review changing concepts of intellectual disability over the centuries to provide a context for current diagnostic and treatment approaches. An awareness of this history provides perspective on the centuries-long struggle to recognize the needs of and to provide support to persons with intellectual disability. Legal safeguards are now in effect and are continuing to emerge as services are established that use a developmental model and emphasize a developmental perspective. This model emphasizes how comprehensive evaluation and positive supports at home and in the community can make a difference in the lives of persons with disabilities. The starting point is a definition of the term “intellectual disability.” This will be followed by a brief historical survey of origins and attitudes that are changing after centuries of stigmatization and separation. National and international efforts, which began in the 1970s, are continuing to encourage community placement of and self-determination by persons with intellectual disability. Although “mental retardation” is the term used in both the International Classification of Diseases (lCD-10) (World Health Organization, 1992) and the Diagnostic and Statistical Manual (DSM-IV, DSM-IVTR) (American Psychiatric Association, 1994, 2000) systems that describe an intellectual and adaptive cognitive disability that begins in early life during the developmental period, the preferred term is “intellectual disability” internationally, especially in English-speaking countries.