The first hint that a condition leading to mental retardation may be present is often determined based on observation of a child's physical and behavioral characteristics. When mental retardation is suspected, the child will typically receive a full physical exam and review of medical history designed to identify any organic (physical or medical) causes of the troubling symptoms. Some organic conditions that can result in mental retardation can be treated effectively; however, even reversible conditions require immediate attention as brain damage can easily be permanent in nature. Hyperthyroidism is an example of a treatable condition that can cause mental retardation to occur if not treated. Individuals who may have a neurological cause to blame for their troubling symptoms (brain injury, for example) are often referred to a neurologist for further testing.
Medical testing is only one part of the full mental retardation testing set, which includes a comprehensive medical exam, a social and familial history, an educational history (if the child is of school age), and intellectual, social, and psychological testing. Parents or primary caretakers are interviewed during this process. In many cases, the child is interviewed as well. Interviews are useful in determining the level at which the child functions during everyday activities. They help determine if the child has the appropriate self-help and social skills for his age.
Intelligence (IQ) and achievement tests are used to determine a child's level of intellectual functioning and ability to learn. Multiple tests of intellectual functioning are available.
The Wechsler Intelligence Scale for Children (WISC) is appropriate for children ages six through sixteen years of age. This test is composed of multiple small tests, each of which provides insight into distinct areas of children's intellectual functioning across two key aspects of intelligence: verbal skills and spatial/performance skills. Tests of vocabulary, similarities, comprehension, math, and information knowledge comprise the verbal test section, while tests of picture completion and arrangement, block design, object assembly, and coding comprise the performance side of the test.
The Wechsler Preschool and Primary Scale of Intelligence is appropriate for children ages three to seven years. This test is organized like the WISC, and measures two key aspects of intelligence: verbal and performance, with multiple individual subtests measuring different aspects of each major area. This test is not appropriate for individuals with severe mental retardation.
The Wechsler Adult Intelligence Scale is used to test individuals who are over sixteen year of age. This test has the same two major areas, verbal and performance, at age appropriate level of difficulty and like the WISC, is comprised of multiple subtests measuring different aspects of the two major areas of intelligence.
The Stanford-Binet Intelligence Scale is used to test individuals ranging from two to twenty-three years of age. There are fifteen subtests for older groups and six (vocabulary, comprehension, pattern analysis, quantitative, bead memory, and memory for sentences) that are administered across all age groups.
