Intellectual Disabilities

Intellectual Disabilities Definitions

Classification by IQ (Wechsler Scales) • 130+ Very Superior (Gifted) • 120-129 Superior • 110-119 High Average • 90-119 Average • 80-89 Low Average • 70-79 Borderline • 69 and below Mental impairment

AAMD/AAMR Classification Systems • Heber (1961) • Borderline 68-84 • Mild 52-67 • Moderate 36-51 • Severe 20-35 • Profound <20

AAMD/AAMR Classification Systems • Grossman (1973) • Mild 52-67 • Moderate 36-51 • Severe 20-35 • Profound <20

AAMD/AAMR Classification Systems • Grossman (1983) • Mild 50-55 to approximately 70 • Moderate 35-40 to 50-55 • Severe 20-25 to 35-40 • Profound <20-25

AAMD/AAMR Classification Systems • Luckasson 1992 • Eliminated levels <70 to 75 • Luckasson 2004 • Retained classification without levels Approximately 2 standard deviations below average considering the standard error of measurement and strengths and weaknesses of the specific instrument

Most recent definition • Mental retardation is a disability characterized by significant limitations in both intellectual functioning and adaptive behavior as expressed in conceptual social and practical adaptive skills. This disability originates before age 18. (2002)

Definition from 1992 • Mental retardation refers to substantial limitations in present functioning. It is characterized by significantly subaverage intellectual functioning existing concurrently with related limitations in two or more of the following applicable adaptive skill areas: …. Mental retardation manifests itself before age 18.

Definition from 1992 • Identified 10 areas of adaptive behavior • Communication • Self care • Home living • Social skills • Community use • Self direction • Health and safety • Functional academics • Leisure • work

DSM-IV. • DSM-IV attempts to blend the 1977 and 1992 definitions put forth by the American Association on Mental Retardation. It adopts the 1992 definition, but retains the severity level classification scheme from the 1977 definition. The upper IQ limit is 70, and an individual must have delays in at least two of the 10 areas outlined in the 1992 definition.

International Classification of Diseases • ICD-10 characterizes mental retardation as a condition resulting from a failure of the mind to develop completely. ICD-10 suggests that cognitive, language, motor, social, and other adaptive behavior skills should all be used to determine the level of intellectual impairment. • ICD-10 supports the idea of dual diagnosis, suggesting that mental retardation may be accompanied by physical or other mental disorders.

AAMR Levels of Support • Intermittent - Support is not always needed. It is provided on an "as needed" basis and is most likely to be required at life transitions (e.g. moving from school to work). • Limited - Consistent support is required, though not on a daily basis. The support needed is of a non-intensive nature.

AAMR Levels of Support • Extensive - Regular, daily support is required in at least some environments (e.g. daily home-living support). • Pervasive - Daily extensive support, perhaps of a life-sustaining nature, is required in multiple environments.

John • John is a 26-year-old man who received special education for most of his schooling. He is currently employed as a night janitor at a brewery. John has worked there for about eight years, having begun on a part-time basis while he was still in high school. He is married and has one child.

John • John began receiving special education while he was in the second grade. During that school year, he was referred for psychological evaluation because he was experiencing severe difficulties in all academic areas.

John was administered the Wechsler Intelligence Scale for Children (WISC-R) on which he attained a full-scale IQ score of 68. • described him as socially immature, but otherwise well adjusted emotionally. • placed in the program for students with educable mental retardation. Throughout the remainder of elementary school, John spent about half the school day in the special education classroom and the remainder of the day in the general classroom.

His intellectual and academic skills have been reevaluated several times with his IQ scores being slightly higher on subsequent assessments. When he was last evaluated at age 17, John attained a full-scale IQ score of 73 on the Wechsler Adult Intelligence Scale. At that time, John's reading and spelling scores were at the 4th-grade level, and his math skills were on 5th-grade level. He was described as an average appearing and likeable young man.

While in high school, John enrolled in some regular classes, but continued to receive tutoring and some course work in the special education program. During his last two years, he was in a work-study program and spent half of the day at his job.

Should clinical judgment have a place in the identification of persons with intellectual disability?

John is the youngest of four children. Neither of his parents finished high school, and his father worked as an unskilled laborer before he retired. Two of John's siblings were also enrolled in special education programs. • Would you consider John to be mentally retarded? Why? • If so, would you consider him to be mild, moderately , or severely retarded?

Intellectual Disability: Typical Characteristics • Individuals with mental retardation are likely to need only intermittent to limited support; • typically do not "look" different from their non-disabled peers; • often have only mild or moderate developmental delays, except in academics, which is often the major area of deficit; • therefore, they are often not identified until they enter the school setting, where their cognitive disability is most apparent;

Characteristics • they typically attain 3rd- to 6th-grade academic achievement levels by the time they finish high school; • as adults, many, though not all, with mild MR will be able to obtain independent employment; • many will marry, have children, and blend rather indistinguishably into the community; for those who achieve total independence, the label of mental retardation is no longer appropriate.

Individuals with moderate to severe intellectual disability… • will probably need limited to extensive supports; • they are more likely to have a recognizable syndrome (such as Down Syndrome); • therefore, may "look" different than their non-disabled peers;. • their development is often significantly delayed; • they are typically identified as infants or toddlers;

…moderate to severe intellectual disability • most begin receiving special education during the preschool years; • they may be included in the regular classroom part of the school day; but often spend much of the school day in a separate classroom where they learn adaptive living skills; • as adults, most individuals with moderate to severe MR will not achieve total independence;

…moderate to severe intellectual disability • they are likely to continue to need limited to extensive support such as that provided in group homes or semi-independent living situations (SILs); some may continue to live with their parents; • some individuals with moderate to severe MR may be able to succeed in modified competitive employment situations; • however, many will work in supported, non-competitive settings such as sheltered workshops.

Individuals with profound intellectual disability: • will generally need services at the pervasive level, typically throughout their life; • they are likely to have multiple disabilities, particularly in the areas of mobility and communication;. • therefore, many use wheelchairs and alternate forms of communication; • their communication deficits make it difficult to accurately assess their intellectual functioning;

…profound mental retardation: • in educational settings, they may be placed along with students with moderate to severe MR or in their own classroom; • some adults with this level of retardation remain in institutional settings, but most currently live in group homes.

Definitions • Summarize definitions and what you know thus far about persons who have a label of mental retardation. What definition would be most useful to a teacher? What information should it include?

Intellectual Disabilities