SW 644: Issues in Developmental Disabilities Intellectual Disability: Definition, Classification and

1
SW 644 Issues in Developmental
DisabilitiesIntellectual Disability Definition,
Classification and Assessment

• Lecture Presenter
• Lara S. Head, Ph.D.
• Post Doctorate Fellow in Psychology
• Waisman Center
• University of Wisconsin-Madison

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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

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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

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Classification

• A classification system is introduced
• J. Langdon Hayden Down
• Classification by physical appearance
• Late 1800s Recognition of brain pathology in
  intellectual disabilities
• Education reform and Residential Schools
• Theodore Simon and Alfred Binet
• Early 1900s
• Classification based on IQ

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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

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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

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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)

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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)

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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

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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

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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

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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

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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

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2002 AAIDD System

• Diagnosis
• Core 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

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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

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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

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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

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2002 AAIDD System Adaptive Behavior

• Social Skills
• Interpersonal skills
• Responsibility
• Self-esteem
• Practical Skills
• Eating
• Dressing/Bathing
• Mobility
• Daily Living tasks

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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

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2002 AAIDD System Supports

• Planning Supports
• Human development
• Teaching and education
• Home living
• Community living
• Employment
• Health and safety
• Behavioral
• Social
• Protection and advocacy

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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

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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

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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/ColemanInstitu
  te/stateofthestates/Wisconsin.html)

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Special Education Services Fall 2005
Site www.ideadata.org
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Special Education Services Fall 2005
Site www.ideadata.org
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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

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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

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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

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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

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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

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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

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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

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Variations in ID Classification

• Childhood intervention history
• Educational experiences
• Socialization opportunities
• Adult habilitative and prevocational activities
• Presence of physical impairment

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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

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Identifying Individuals with ID

• Assessment
• Cognitive/intellectual ability
• Adaptive behavior functioning

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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 individuals 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?

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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 lt 70 approximately 3

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Cognitive Ability Assessment

• Normal Curve

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Cognitive Ability Assessment

• Types of Intelligence
• Verbal Ability
• Nonverbal Ability
• Other theoretical models

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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

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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

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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 individuals
  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 individuals 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

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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)

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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

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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

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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

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Adaptive Behavior Assessment

• Current standards of practice
• Assess present functioning
• Assess typical functioning
• Consider the persons age and culture
• Assessment using standardized measure of AB
  normed on general population
• Compare persons adaptive behavior to community
  standards and expectations
• Use multiple informants
• Retrospective assessment (Schalock et al., 2007)

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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

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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)

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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 familys coping style

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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

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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)

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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

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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

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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

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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-th
  e-joy-of-adam/
• www.cdlsusa.org/familyalbum/index.html --
  Cornelia de Lange Syndrome Images CDLS
  Foundation

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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?contentid444
  International Rett Syndrome Association
• www.youtube.com/watch?v_TbWcdN-W8o Living a
  Life of Disability video

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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.

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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). Users Guide Mental retardation
  Definition, classification, and systems of
  supports (10th ed.). Washington, DC American
  Association on Intellectual and Developmental
  Disabilities.

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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.