International Review of Research in Mental Retardation (eBook)

eBook Download: EPUB

1999 | 1. Auflage
298 Seiten
Elsevier Science (Verlag)
9780080546117 (ISBN)

Infos

International Review of Research in Mental Retardation is an ongoing scholarly look at research into the causes, effects, classification systems, syndromes, etc. of mental retardation. Contributors come from wide-ranging perspectives, including genetics, psychology, education, and other health and behavioral sciences. Volume 22 is an eclectic volume with chapters on genetics, developmental skills, and methodological issues, as well as review chapters on the Savant Syndrome, and supported employment programs. Contributors for this volume are from the U.S., U.K., and Australia.

Inhalt

Front Page 1
International Review of Research in Mental Retardation, Volume 22 4
Copyright Page 5
Contents 6
Contributors 10
Preface 12
Chapter 1. Direct Effects of Genetic Mental Retardation Syndromes: Maladaptive Behavior and Psychopathology 16
I. Direct Effects: Psychopathology as Example 17
ll. Syndrome Review 19
lll. Challenges and Advantages to Phenotypic Work 28
IV. Toward Increased Phenotypic Work 35
References 37
Chapter 2. Indirect Effects of Genetic Mental Retardation Disorders: Theoretical and Methodological Issues 42
I. Understanding the Workings of Direct Effects 43
ll. Conceptualizing Indirect Effects 45
lll. Indirect Effects in Mental Retardation 48
IV. Remaining Issues 57
V. Conclusion 62
References 62
Chapter 3. The Development of Basic Counting, Number, and Arithmetic Knowledge among Children Classified as Mentally Handicapped 66
I. Rationale for Reforming Mathematics Instruction 67
ll. The Mathematical Learning of Children with Mental Retardation 72
lll. Implications 98
References 110
Chapter 4. The Nature and Long-Term Implications of Early Developmental Delays: A Summary of Evidence from Two Longitudinal Studies 120
I. History and Current Status of the Category and Concept of Developmental Delay 120
lI. REACH and CHILD Children in the Preschool Years 122
lll. Competence and Problems of Children with Delays 129
IV. Family Responses to Children with Developmental Delays 132
V. Generalizations and Observations from Two Longitudinal Studies 142
References 145
Chapter 5. Savant Syndrome 152
I. Introduction 152
lI. Definition and Incidence 153
lll. The Skills of Savants 155
lV. Savant Skills and Intelligence 157
V. Memory 160
VI. Talent 167
VII. Explaining Savant Syndrome 174
VIII. Conclusions 179
References 181
Chapter 6. The Cost-Efficiency of Supported Employment Programs: A Review of the Literature 190
I. Introduction 190
ll. Overview of Benefit-Cost Analyses 191
III. Methodological Differences 194
lV. Studies Examing the Perspectives of the Working, the Taxpayer, and Society 195
V. Summary of Society’s Perspective 207
VI. Studies Examining the Perspectives of the Worker and the Taxpayer 210
VII. Summary of the Taxpayer’s Perspective 214
VIII. Studies Examining the Perspective of the Worker 217
IX. Summary of the Worker's Perspective 228
X. Conclusions 232
References 236
Chapter 7. Decision Making and Mental Retardation 242
I. Introduction 242
ll. Research and theory in mental retardation 244
lll. Decision Theory 253
IV. A Framework for Decision-Making Research 262
V. Conclusions and Future Directions 271
References 274
Chapter 8. “The Child That Was Meant?” or “Punishment for Sin?”: Religion, Ethnicity, and Families with Children with Disabilities 282
I. Introduction 282
ll. Religion and Disability 285
lll. Religion and Disability in African-American Families 286
IV. Religion and Disability in Latino Families 291
V. A Model of Religion, Ethnicity, and Disability 294
VI. Summary and Conclusions 299
References 300
Index 304

Textauszug

Direct Effects of Genetic Mental Retardation Syndromes: Maladaptive Behavior and Psychopathology

Elisabeth M. Dykens    Neuropsychiatric Institute University Of California, Los Angeles Los Angeles, California

Sparked by revolutionary advances in the Human Genome Project, researchers are increasingly concerned with how genetic diseases are manifest at the genetic, physical, behavioral, and developmental levels. Yet for many reasons, research on genetic syndromes has trickled into the field of mental retardation at a relatively slow pace (Dykens, 1996). Even so, syndromic findings have already had a profound impact on the developmental disability field, especially in the area of psychopathology.

Most work on mental retardation syndromes focuses on so-called direct behavioral effects, or the ways in which a genetic diagnosis predisposes persons to show certain behaviors relative to those without the diagnosis. This chapter focuses on many of the complexities involved in studying direct effects, otherwise known as behavioral phenotypes. These complexities include defining and measuring phenotypes; assessing genetic and psychosocial sources of within-syndrome behavioral variability; and examining unique versus shared behaviors across syndromes.

In contrast, syndromes are also characterized by so-called indirect effects, or how syndrome-specific behaviors elicit reactions from others, such as parents, siblings, peers, and teachers. Less researched than direct effects, work on indirect effects assesses how different syndromic phenotypes set the stage for different types of interactions with others. As described by Hodapp (1997) elsewhere, and in his chapter in this volume, indirect effects are primarily concerned with the person’s effects on others, and the person-environment transactions that are elicited by various behavioral phenotypes.

To briefly illustrate these two approaches, consider possible direct and indirect effects of children with Down syndrome. As described later in this chapter, direct effects include a controversial but persistent personality stereotype involving a pleasant and charming demeanor, as well as fewer and less severe maladaptive behaviors relative to other children with mental retardation. As discussed in Hodapp’s chapter on indirect effects, these features, in turn, may be associated with less family stress, fewer sibling concerns, and more family harmony and cohesion.

In short, then, the two complementary chapters in this volume on direct and indirect effects both clarify and expand key assumptions about behavioral phenotypes. But work on behavioral phenotypes is actually at its beginning stages, and researchers within this growing speciality often struggle with basic conceptual, definitional, and measurement issues. This chapter on direct effects takes up many of these issues, with particular reference to within- and between-syndromic differences, logistical and attitudinal challenges to phenotypic research, and the importance of phenotypic work for furthering our understandings of gene-brain–behavior relationships. Hodapp’s subsequent chapter on indirect effects further expands phenotypic work, showing how different behavioral phenotypes shape interactions with others. Although child effects on adults or peers are increasingly studied in other fields, such as developmental psychology, this approach has yet to be applied to people with genetic mental retardation syndromes. The two chapters on direct and indirect effects show both the problems and promise in conducting research on specific genetic mental retardation syndromes.

I DIRECT EFFECTS: PSYCHOPATHOLOGY AS EXAMPLE

Phenotypic research should examine the profiles and developmental trajectories of a broad range of behavior, including domains such as cognition, achievement, speech, language, personality, adaptive skills, and social competence (Dykens, 1995). Yet most studies on direct effects focus on maladaptive behavior or psychopathology, in part because of the clinical urgency associated with these problems. I primarily use psychopathology in various syndromes as examples of direct effects of genetic mental retardation syndromes.

Before considering psychopathology in people with syndromes, however, some background information is necessary about maladaptive behavior in people with mental retardation in general. Relative to the general population, people with mental retardation are twice as likely to suffer from psychiatric disorders or significant psychopathology. It is now well appreciated that people with mental retardation show the full range of psychiatric disease, as well as a host of maladaptive behaviors rarely seen in the general population, such as stereotypies and self-injury. These problems are the leading culprits for failed residential, educational, and vocational placements, and they often lead people with mental retardation to need more restrictive levels of care.

In all this work, however, researchers have yet to decipher why people with mental retardation are at increased risk for psychopathology in the first place. In the absence of any well-proven theory, workers have hypothesized many reasonable explanations for the co-occurrence of mental retardation and psychiatric dysfunction, often referred to as dual diagnosis. In the most comprehensive hypothesis to date, Matson and Sevin (1994) propose a biopsychosocial theory of dual diagnosis. In this model, psychopathology is attributed to a confluence of factors, including limited skills in cognitive, adaptive, social, linguistic, and memory functioning; organic problems such as neurologic and genetic abnormalities, epilepsy, biochemical and sensory impairments; aberrant patterns of learning and behavioral reinforcement, such as learned helplessness and social deprivation; aberrant personality styles; psychosocial stressors; heightened family stress; de-institutionalization; and societal stigma. Although comprehensive, it is unclear the exact role that each of these risk factors plays in the development of psychopathology.

In this chapter, I propose that examining genetic etiology of mental retardation is an important first step in sorting out the relative importance of the many risk factors for psychopathology. Differentiating genetic from psychosocial risk factors is a particularly promising strategy as it takes advantage of recent and dramatic breakthroughs in molecular genetics and the Human Genome Project. Over 750 known genetic causes of mental retardation have now been identified (Opitz, 1996), and more accurate diagnostic procedures for both new and previously known syndromes will result in more and more people being diagnosed with genetic syndromes in the years ahead. Indeed, prevalence studies suggest that genetic syndromes may already account for 40 to 50% of people with developmental delay (e.g., Matilanen, Airaksinen, Monen, Launiala, & Kaariainen, 1995). Further, mental retardation syndromes have been pivotal to the discoveries of new mechanisms of human disease, leading to revolutionary advances in the genetics field.

Despite these remarkable accomplishments, however, genetic etiology has yet to be widely studied by behavioral researchers in the mental retardation field. In particular, most behavioral and dual diagnosis researchers use subject groups with heterogeneous etiologies (Dykens, 1995, 1996; Hodapp & Dykens, 1994). Thus, persons with known syndromes or other organic causes for their delay are mixed together in the same group, along with subjects with unknown etiologies. Subsequent behavioral data are then analyzed by age, IQ, level of impairment, gender, or residential status (see Borthwick-Duffy, 1994, for a review).

To show this, I reviewed Aman’s (1991) comprehensive bibliography of articles published between 1970 and 1990 on behavioral and emotional problems in people with mental retardation. Over this 20-year period, only 11% of the articles (41 out of 375) were devoted to people with specific genetic syndromes. Most of these syndrome-specific studies were on Down syndrome (n = 24), leaving just a handful of studies on people with all other genetic disorders. The majority of articles (89%) used heterogeneous subjects and did not examine etiology at all. These very same percentages were seen as well in a review of psychopathology articles from 1990 to 1995 (Dykens, 1996).

It makes it hard, if not impossible, to sort out genetic from psychosocial risk factors for psychopathology if 90% of dual diagnosis studies simply ignore the genetic etiology of their participants. One way to advance a greater understanding of psychopathology is to examine groups of people with discrete genetic disorders. Although rare relative to mixed groups, syndrome-specific studies to date find strong associations between genetic syndromes and distinctive patterns of psychopathology.

This chapter reviews maladaptive and psychiatric features in six of these syndromes, including fragile X syndrome, Williams syndrome, Prader-Willi syndrome, Down syndrome, 5p- syndrome, and Smith-Magenis syndrome. Although not representative of all 750 or so syndromes, these disorders have rich or growing databases, and demonstrate both the advantages and problems in conducting phenotypic research. Findings from these syndromes also hold much promise for identifying specific genetic, brain, and biochemical pathways to psychiatric problems in people with or without mental retardation.

After the syndrome review, I discuss broader considerations in conducting phenotypic research, including how to define a behavioral phenotype, to appreciate...

Produkt-Details

• Erscheint lt. Verlag: 7.6.1999
• Mitarbeit: Herausgeber (Serie): Laraine Masters Glidden
• Sprache: englisch
• Themenwelt: Geisteswissenschaften ► Psychologie ► Allgemeine Psychologie
• Themenwelt: Geisteswissenschaften ► Psychologie ► Entwicklungspsychologie
• Themenwelt: Geisteswissenschaften ► Psychologie ► Klinische Psychologie
• Themenwelt: Geisteswissenschaften ► Psychologie ► Pädagogische Psychologie
• Themenwelt: Geisteswissenschaften ► Psychologie ► Verhaltenstherapie
• Themenwelt: Medizin / Pharmazie ► Gesundheitswesen
• Themenwelt: Medizin / Pharmazie ► Medizinische Fachgebiete ► Neurologie
• ISBN-13: 9780080546117 / 9780080546117