Mental Retardation

Mental Retardation Carol Ann Heath Developmental of Young Children with Disabilities

Historical Perspective • Dates back to beginning of time • Found in history of Thebes, Egypt around 1500 BC • Terms: feeblemindedness, mental deficiency • Infanticide was a common practice • Sold for entertainment/amusement • Middle ages saw advances

Progress • In 1690, John Locke published An Essay Concerning Human Understanding (tablula rasa or blank slate) • Work of Jean-Marc-Gaspard Itard hired in 1800 to work with Victor who lived whole life in the woods • 1850 Seguin developed Physiological Method – sensory training

1908 Binet developed intelligence test • 1970 Wyatt-Stickney case-class action suit establishing right to treatment • 1975 Congress passed Education for the Handicapped Act

What is Mental Retardation • An individual is considered to have mental retardation if: • Intellectual functioning IQ <70 • Significant limitations in tow or more adaptive skill areas • Present from childhood

IDEA Definition “Mental retardation means significantly subaverage general intellectual functioning existing concurrently with deficits in adaptive behavior and manifested during the developmental period, that adversely affects a child’s educational performance.”

DSM-IV • Blends the 1977 & 1992 definitions put forth by the American Association on Mental Retardation (AAMR) • Upper IQ limit 70 • Affects two of ten areas

ICD-10 • Tenth revision of the International Classification of Diseases from the World Health Organization • Characterizes MR as a condition resulting from a failure of the mind to develop • Four levels

What are adaptive skills? Adaptive skill areas are those daily living skills needed to live, work and play in the community

Adaptive Skill Areas • Communication • Self-care • Home living • Social skills • Leisure • Health & safety • Self-direction • Functional academics • Community use • Work

Incidence • .5% of preschool population • 2.5 to 3 % of school age population • 75% of mental retardation is mild • 20% is moderate • 5% is severe or profound

Prevalence • Mild MR most prevalent among lower socioeconomic groups • Moderate and severe mental retardation is more evenly distributed across all socioeconomic levels

Prevalence • 1990 census: 6.2 to 7.5 million • Affects 1% of the general population • 1.7% of total school population • Ranges from mild to severe • 87% mildly affected • 13% moderately affected with IQ less than 50

Mental Age • The term mental age is used in intelligence testing • Means that the individual received the same number of correct responses on a standardized IQ test as the average person of that age in the sample population • Refers to the intelligence test score

Diagnosis- Step 1 • Qualified person gives one or more standardized intelligence tests and standardized adaptive skills test, on an individual basis

Diagnosis- Step 2 • Describe person’s strengths and weakness across four dimensions: • Intellectual/adaptive behavior • psychological/emotional issues • physical/health etiological issues • environmental issues

Diagnosis- Step 3 • Interdisciplinary team to determine needed supports • Four levels of intensity: intermittent- as needed basis limited- over limited time span extensive- daily basis pervasive- constant support

Are the Causes Known? • If mild to moderate range, the cause will probably not be identifiable • There is no curative treatment, even for most known causes • Brain damage is irreversible • Some causes are genetic

Causes • Genetic conditions • Problems during pregnancy • Problems at delivery • Problems at/after birth • Childhood illness or trauma • Poverty/Deprivation

Conditions and MR: Pre- & Peri-conceptual • Metabolic disorders: • Mucopolysaccharidoses • Tay-Sachs disease • Brain Malformation: • Encephalocele • Hydranencephaly • Neurocutaneous syndromes: • Tuberous sclerosis • Neurofibromatosis • Chromosomal abnormalities: • Down syndrome • Cri-du-chat syndrome

Prenatal • Teratogens • Chemicals • Radiation • Alcohol • Infection • Rubella • Cytomegalorvirus • Fetal malnutrition Mother with high blood pressure or kidney disease

Perinatal • Prematurity Complications, e.g. poor oxygenation of the brain & intracranial hemorrhage • Metabolic abnormalities • Asphyxia at birth • Hypoglycemia • Trauma • Misapplication of forceps • Infection • Herpes simplex • Encephalitis

Postnatal • Infection- meningitis • Trauma- auto & child abuse • Lack of oxygen • Drowning • strangulation • Severe nutritional deficiency • Environmental toxins- lead • Environmental & social problems • Parental psychiatric disorders • psychosocial deprivation

Identification • Suggested by delays in obtaining developmental milestones • Poor performance on formal cognitive tests- two or more SD • Tests are more predictive w/older & those with more delay • Tests rely on sensorimotor function • Tests are dependent on child’s experiences

Prevention • Prenatal care • Newborn screening • Vaccines • Lead removal • Child safety

Educational Implications In teaching: Use concrete materials, age-appropriate Present info in small, sequential steps Provide prompt feedback LRE issues Structure steps and teach each step

An estimated 2.5 million people in the United States have an intellectual disability- approximately 1% of the United States population. • Estimates also indicate that only 31% of individuals with intellectual disabilities are employed, although many more want to work. Source: http://www.eeoc.gov/facts/intellectual_disabilities.html

Intellectual disabilities will vary in degree and effect from person to person, just as individual capabilities vary considerably among people who do not have an intellectual disability. • People should not make generalizations about the needs of persons with intellectual disabilities. In some instances an intellectual disability will not be obvious from a person's appearance, nor will it be accompanied by a physical disability. Source: http://www.eeoc.gov/facts/intellectual_disabilities.html

Mental Retardation