sw 644: issues in developmental disabilities intellectual disability: definition, classification and...
TRANSCRIPT
SW 644: Issues in Developmental DisabilitiesIntellectual Disability: Definition,
Classification and Assessment
Lecture Presenter:Lara S. Head, Ph.D.Post Doctorate Fellow in PsychologyWaisman CenterUniversity of Wisconsin-Madison
Issue of Change: Providing Context Terminology
Shift from ‘mental retardation’ to ‘intellectual disability’
Definition Evolving
Assessment Balance between intelligence and
adaptive behavior Implications
Increasing consistency
Issue of Change - Terminology Historical conceptualizations
Presence of individuals with intellectual impairments in society has been well documented over time (Example: Roman and Greek Culture)
Early religious leaders were among first to advocate for humane treatment
Changing perceptions John Locke Jean-Marc-Gaspard Itard Edouard Seguin
Classification A classification system is introduced
J. Langdon Hayden Down Classification by physical appearance
Late 1800’s: Recognition of brain pathology in intellectual disabilities
Education reform and Residential Schools Theodore Simon and Alfred Binet
Early 1900s Classification based on IQ
What is Intellectual Disability? Current Perspective
A state of functioning rather than a person-centered trait
Limitations in intellectual functioning Difficulties in meeting the ordinary
challenges associated with daily life A social-ecological view
Not an illness or a disease Medical model view Perception of ‘sick’
What is Intellectual Disability? Types of causes
Genetic Chromosomal Prenatal influences Perinatal influences Postnatal influences
Diagnosis of intellectual disability is a process No single diagnostic test
Defined by many organizations
Terminology Differences Many different terms to describe
intellectual disability Shift in terminology in last few years Mental Retardation / Intellectual
Disability Significant limitations in intellectual
functioning and in adaptive behavior Before 18 Population of application remains the
same (www.aaidd.org)
Terminology Differences Developmental Disability
A severe, chronic disability that begins any time from birth through age 21 and is expected to last a lifetime.
May be cognitive, physical, or a combination of both
Serious limitations in everyday activities (www.nacdd.org)
Disability Personal limitations that represent a
substantial disadvantage with attempting to function in society
Can originate at any age (www.aapd.org)
Terminology Differences Benefits to terminology change
Reflects the changed construct of disability Aligns better with current professional
practices Provides a logical basis for individualized
supports provision Less offensive to individuals with disability More consistent with international
terminology
Issue of Change- Definition Definition
Evolving and dependent on assumptions that clarify the context from which it is derived and applied
Significant consequences Service eligibility Subject or not subject to certain practices Exempted or not exempted Included or not included Entitled or not entitled
Development of Definition
1961: AAMR introduces term “mental retardation”
1973: Introduction of standard deviation to describe intellectual disability as well as 18 as upper age limit for initial manifestation of intellectual disability
1980s: Specific IQ values with ranges
2002 AAIDD System
Diagnosis Essential to establishing eligibility
Classification A means of communication
Planning Supports Enhancing personal outcomes
Four different definitions for intellectual disability: focus on DSM IV and AAIDD
2002 AAIDD System
Multidimensional Approach Other systems, like DSM IV, is multi-
axial and focuses on medical disorders and stressors
Important to assess current functioning and strengths of individual
2002 AAIDD System
DiagnosisCore definition (2002)
Mental retardation is a disability characterized by significant limitations in intellectual functioning and in adaptive behavior
Is expressed in conceptual, social, and adaptive skills
Originates before age 18
2002 AAIDD System 5 essential assumptions
Limitations must be considered within context Diagnosis based on a valid assessment that
considers various factors Recognizes that limitations and strengths
coexist Limitations provide information to develop
support needs With personalized supports provided over
time, life functioning will improve
2002 AAIDD System: Intelligence General mental capacity includes:
Reasoning Problem-solving Abstract thinking Comprehension Learning from experience
Limitations influence other aspects of functioning
Best represented by intelligence test scores using appropriate test instruments
2002 AAIDD System: Adaptive Behavior
Collection of skills that individuals learn to use in order to function in everyday life
Conceptual Skills Receptive and expressive language Reading and writing Money concepts Self-directions
2002 AAIDD System: Adaptive Behavior
Social Skills Interpersonal skills Responsibility Self-esteem
Practical Skills Eating Dressing/Bathing Mobility Daily Living tasks
2002 AAIDD System: Classification Classification Dimension I
Intellectual Abilities Dimension II
Adaptive Behavior Dimension III
Participation, Interactions, and Social Roles
Dimension IV Health
Dimension V Context
2002 AAIDD System: Supports
Planning Supports Human development Teaching and education Home living Community living Employment Health and safety Behavioral Social Protection and advocacy
DSM IV – TR Definition Significantly below average intellectual
functioning: IQ of approximately 70 or below on an individually administered IQ test
Accompanied by significant limitations in adaptive functioning in at least 2 skill areas: Communication, self-care, home living,
social/interpersonal skills, use of community resources, self-direction, functional academic skills, work leisure, health, and safety (American Psychiatric Association, 2000, p. 41)
Onset before age 18
DSM IV-TR Levels of Mental Retardation Mild MR
55-70 IQ Adaptive limitations in 2 or more domains
Moderate MR 35-54 IQ Adaptive limitations in 2 or more domains
Severe MR 20-34 IQ Adaptive limitations in all domains
Profound MR Below 20 IQ Adaptive limitations in all domains
Who are the Intellectually Disabled?
Prevalence Less than 1% of the overall population Estimated 3% of the population in the United
States Residence
WI Approximately 81% reside in a
home/supported living setting Approximately 19% reside in a state
public/private facility (www.cu.edu/ColemanInstitute/stateofthestates/Wisconsin.html)
Special Education Services – Fall 2005
State Ages 3-21Wisconsin 130,076
Minnesota 116,511
Illinois 323,444
Michigan 243,607
Indiana 177,826
Iowa 72,457
Site: www.ideadata.org
Special Education Services – Fall 2005Disability Category Age 5 Age 10
Specific Learning Disabilities 7,607 235,787
Speech/Language Impairments 164,082 115,780
Mental Retardation 11,688 36,678
Emotional Disturbance 3,373 30,579
Multiple Disabilities 4,171 9,753
Hearing Impairments 3,228 5,909
Orthopedic Impairments 3,407 5,313
Other Health Impairments 6,590 51,225
Visual Impairments 1,349 2,093
Autism 13,848 18,216
Deaf-blindness 86 112
Traumatic Brain Injury 504 1,729
Developmental Delay 82,261 0
All Disabilities 302,194 512,994
Site: www.ideadata.org
Who are the Intellectually Disabled?
Age differences Increased prevalence typically from
preschool to middle childhood years Increased prevalence in teen years Decreased prevalence in older individuals
Gender differences Increased reports in males
Who are the Intellectually Disabled?
Associated impairments 20-25% visually impaired 10% hearing impaired Seizure disorders occur in
approximately 33% of individuals in institutional settings
Cerebral palsy occurs 30-60% of individuals in individuals with severe intellectual disability
Who are the Intellectually Disabled?
Psychiatric disorders Estimates of 4-18% of individuals with ID
have a co-occurring psychiatric disorder 4.4% Schizophrenia 2.2% Depressive disorder 2.2% Generalized Anxiety Disorder 4.4% Phobic disorder
Deb, Thomas, & Bright 2001
Profiles of Intellectual Disability
Mild ID Profile Minor delays in the preschool period Evaluation often only after school entry 2-3 word sentences used in early primary
grades Expressive language improvement with time Reading/math skills – 1st to 6th grade levels Social interests typically age appropriate Mental age range of 8-11 years of age Persistent low academic skill attainment can
limit vocational possibilities
Profiles of Intellectual Disability Moderate ID Profile
More evident and consistent delays in milestones
At school entry may communicate with single words and gestures
Functional language is the goal School entry self-care skills – 2-3 year range By age 14: basic self-care skills, simple
conversations, and cooperative social interactions
Mental age of 6-8 years of age Vocational opportunities limited to unskilled
work with direct supervision and assistance
Profiles of Intellectual Disability
Severe ID Profile Identification in infancy to two years Often co-occurring with biological anomalies Increased risk for motor disorders and epilepsy By age 12: may use 2-3 word phrases Mental age typically 4-6 years of age As adults assistance typically required for even
self-care activities Close supervision needed for all vocational tasks
Profiles of Intellectual Disability Profound ID Profile
Identification in infancy Marked delays and biological anomalies Preschool age range may function as a 1-year-
old High rate of early mortality By age 10: some walk/acquire some self-care
skills with assistance Gesture communication Recognizes some familiar people Mental age range from birth to 4 years of age Functional skill acquisition not likely
Variations in ID Classification
Childhood intervention history Educational experiences Socialization opportunities Adult habilitative and prevocational
activities Presence of physical impairment
Issue of Change - Assessment
Assessment Establishing a balance between
the importance of IQ and identifying functional behaviors and support needs
Increased recognition of the cultural implications of intelligence testing
Identifying Individuals with ID
Assessment Cognitive/intellectual ability Adaptive behavior functioning
Cognitive Ability Assessment Standardized and Norm-referenced Tests
Standardized: a test given in a certain, prescribed way using the same set of directions with every individual
Norm-referenced: Examining an individual’s test performance in comparison to the average performance or “norm”, of other individuals of the same chronological age
Validity and Reliability Validity: Does the test measure what we
want? Reliability: Does the test measure
consistently?
Cognitive Ability Assessment Normal Curve / Distribution
Represents the distribution of abilities in the general population
Demonstrates the extent to which individuals deviate from the mean based on a normal distribution of scores
Average IQ = 100 Range 85-115 = approximately 68% Fewer people are represented at the
extreme ends of the curve IQ < 70 = approximately 3%
Cognitive Ability Assessment Normal Curve
Cognitive Ability Assessment
Types of Intelligence Verbal Ability Nonverbal Ability Other theoretical models
Cognitive Ability Assessment
Common Measures WISC Series (WISC IV; WAIS II; WPPSI,
etc.) Stanford-Binet V Woodcock-Johnson Test of Cognitive
Abilities Bayley Scales of Infant Development Kaufman Assessment Battery for
Children
Cognitive Ability Assessment
Stability over time For most, intelligence remains stable
after 5 years of age (Zigler, Balla, & Hodapp, 1984)
However, variability in individual growth patterns warrant periodic evaluation
Other Consideration in Cognitive Ability Assessment How reliable and valid was the test Other Important Features: culture, language barriers, physical impairments Ability to accurately compare individual’s performance against a normative
group when presence of some physical issues Need to be vigilant with these issues when conducting testing, review the
literature and talking to individuals and their families Also consider if there was a great deal of scatter within the individual’s
performance? Intellectual disability is a feature of many different conditions, many
different disorders The diagnosis of intellectual disability should always be made whenever the
diagnostic criteria are met regardless of whether or not there are other conditions that are present
Individuals with intellectual disability are vulnerable to lots of other conditions simply by the nature of how they do function and the nature by which their ability to execute their skills effectively can be compromised
Adaptive Behavior Assessment
“The adaptive behavior approach was originally intended to encourage one to look at the individuals with an eye toward remediation and prescriptive assessment, rather than merely labeling and classifying.” (Nihira, 1999, p. 8)
Adaptive Behavior Assessment
Adaptive behavior can be difficult to assess: Adaptive behavior is not
independent of intelligence Behaviors accepted as adaptive at
one age may not be acceptable at another age
What constitutes adaptive behavior is variable
Adaptive Behavior Assessment Adaptive Behavior
Conceptual Skills:communication, functional academics, self-direction, money concepts
Social Skills:interpersonal skills, self-esteem, naiveté/gullibility, self-governance (obeys rules)
Practical Skills:self-care, domestic skills, work, health & safety
Adaptive Behavior Assessment
Relationship between IQ and adaptive behavior functioning r = .30 -.50 (Harrison & Oakland, 2003)
Highest correlation in the lower IQ ranges
More variability in adaptive behavior scores in higher IQ ranges
Adaptive behavior and intelligence work together
Adaptive Behavior Assessment Current standards of practice
Assess present functioning Assess typical functioning Consider the person’s age and culture Assessment using standardized measure of
AB normed on general population Compare person’s adaptive behavior to
community standards and expectations Use multiple informants Retrospective assessment (Schalock et al.,
2007)
Adaptive Behavior Assessment Measures
Vineland II Adaptive Behavior Scales (Sparrow, Cicchetti, & Balla, 2005) Birth to age 90 Three versions Four Domains – Communication, Daily Living
Skills, Socialization, Motor Skills Maladaptive Behavior Domain Adaptive behavior composite score Survey scale norms based on 3,000+ people
Adaptive Behavior Assessment Measures
AAMR Adaptive Behavior Scales (ABS) School/Community (Lambert, Nihira, & Leland,
1993) Residential/Community (Nihira, Leland, &
Lambert, 1993) Scales of Independent Behavior– Revised (SIB-R)
(Brunininks, Woodcock, Weatherman, & Hill, 1996) Adaptive Behavior Assessment System 2nd
Edition (ABAS – II) (Harrison & Oakland, 2003)
Why Change? - Implications Professional-Parent Communication
Maximize the role of professional in shaping parent perceptions
Recognize the adaptation process as an evolving experience for parents
Need to listen to and value the perspectives of parents
Consider the unique needs of all family members
Need to be sensitive about dreams and hopes of parents for their children
Need to respect family’s coping style
Why Change? Service Provision
Effective resource utilization Lifetime expenditure -- $51.2 billion for
individuals with ID (www.cdc.org) Increased emphasis on adaptive
behavior functioning and habilitation services
Utilizing support needs assessment as a tool towards improved interventions
Why Change? Legal Implications
Identifying individuals at risk as vulnerable adults
Individuals within the criminal justice system As victims – 4 to 10 times increased
risk (Sobsey, 1994) As suspects/offenders – 4-10% of the
prison population (Sullivan & Knutson, 2000)
Future Directions Research / discussion will continue
Refining the construct of intellectual disability Understanding the influence of terminology Expanding our understanding of the nature of
intelligence, adaptive behavior and functional differences
Improving reliability of diagnosis Improving knowledge of human functioning Examining the relationships among groups Determining support provision Recognizing the role of advocacy
Resources - Websites www.aaidd.org – American Association on Intellectual and
Developmental Disabilities (formerly AAMR)
www.nacdd.org – National Association of Councils on Developmental Disabilities
www.familyvillage.wisc.edu – Family Village (University of Wisconsin-Madison)
www.fragilex.org – National Fragile X Foundation
www.cureautismnow.org – Cure Autism Now
Resources - Websites
www.autism-society.org – Autism Society of America
www.ndss.org – National Down Syndrome Society
www.mpssociety.org/content/4163/Tributes/ -- National MPS Society (Hunter syndrome)
www.ideadata.org – Special Education Population Figures – Federal/State
www.cu.edu/ColemanInstitute/stateofthestates -- Disability Population Figures – State
www.aapd.org – American Association of People with Disabilities
Resources – Video/Images www.fragilex.org/photogallery/photogallery.htm -- Fragile X
photographs
www.taaproject.com/media/the-taap-video/ -- Autism Acceptance Project
www.taaproject.com/media/video-vault/the-reason-the-joy-of-adam/
www.cdlsusa.org/familyalbum/index.html -- Cornelia de Lange Syndrome Images – CDLS Foundation
Resources – Video/Images www.cdlsusa.org/video/index.shtml -- CDLS Video
www.ucp.org/ucp_generalsub.cfm/1/9/12171 -- United Cerebral Palsy “One Life”
www.lndinfo.org/LNDPatients/Equipment.html -- Lesch-Nyhan Disease Registry – Images
www.rettsyndrome.org/content.asp?contentid=444 – International Rett Syndrome Association
www.youtube.com/watch?v=_TbWcdN-W8o – Living a Life of Disability video
Resources – Further Reading American Psychiatric Association. (2000). Diagnostic and
statistical manual of mental disorders (4th ed., Text rev.). Washington, DC: Author.
Deb, S., Thomas, M., & Bright, C. (2001). Mental disorder in adults with intellectual disability: Prevalence of functional psychiatric illness among a community-based population aged between 16 and 64 years. Journal of Intellectual Disability Research, 45 (6), 495-505.
Elks, M. A. (2005). Visual Indictment: A contextual analysis of The Kallikak Family photographs. Mental Retardation, 43 (4), 268-280.
Luckasson, R., Borthwick-Duffy, S., Buntinx, W. H. E., Coulter, D. L., Snell, M. E., Spitalnik, D. M. Spreat, S., & Tasse´, M. J. (2002). Mental Retardation: Definition, classification, and systems of supports (10th ed.). Washington, DC: American Association on Mental Retardation.
Resources – Further Reading Snell, M. E. & Vorrhees, M. D. (2006). On being labeled with
mental retardation. In H. N. Switzky & S. Greenspan (Eds.), What is mental retardation: Ideas for an evolving disability (pp. 61-80). Washington, DC: American Association on Mental Retardation.
Sattler, J. & Hoge, R. D. (2006). Assessment of children: Behavioral, social, and clinical foundations (5th ed.). Jerome M. Sattler, Publisher, Inc.: San Diego, CA.
Schalock, R.L., Buntinx, W., Borthwick-Duffy, A., Luckasson, R., Snell, M., Tasse´, M., & Wehmeyer, M. (2007). User’s Guide: Mental retardation: Definition, classification, and systems of supports (10th ed.). Washington, DC: American Association on Intellectual and Developmental Disabilities.
Resources – Further Reading Schalock, R. L. et al. (2007). The renaming of mental
retardation: Understanding the change to the term intellectual disability. Intellectual and Developmental Disabilities, 45 (2), 116-124.
Sullivan, P. & Knutson, J. (2000). Maltreatment and disabilities: A population-based epidemiological study. Child Abuse & Neglect, 24 (10), 1257-1273.
Turnbull, R., Turnbull, A., Warren, S., Eidelman, S. & Marchand, P. (2002). Shakespeare redux, or Romeo and Juliet revisited: Embedding a terminology and name change in a new agenda for the field of mental retardation. Mental Retardation, 40 (1), 65-70.
Zigler, E., Balla, D., & Hodapp, R. (1994). On the definition and classification of mental retardation. American Journal of Mental Deficiency, 89 (3), 215-230.