When assessing for ADHD, a clinician may use a test that gauges the child's abilities, such as the Wechsler Intelligence Scale for Children. Learn about the Wechsler Intelligence Scale for Children, or WISC, and how it is used for ADHD testing.
Overview of the Test
The Wechsler Intelligence Scale for Children, abbreviated as the WISC, is a psychological test given to children between ages 6 years old and 16 years and 11 months old. Nova Southeastern University states that the WISC has four main indexes: verbal concept formation, non-verbal and fluid reasoning, working memory and processing speed. The test is adapted for the child's age, and is used for intelligence and cognitive functioning examination. In the WISC-R, published in 1974, a verbal, performance or full scale IQ below 69 was considered “mentally deficient." That wording has now changed to a more politically correct term: "extremely low." The WISC has gone under many revisions since its first publication in 1949. The WISC-III was printed in 1991, and the latest version, WISC-IV, was released in 2003.
Wechsler Intelligence Scale Changes
The WISC has been revised over the years to change colloquialisms that are not longer relevant, and to reduce any discrimination. Nova Southeastern University states that in the WISC-IV, new subtests were included: letter-number sequencing, word reasoning, cancellation, matrix reasoning and picture concepts. Three sub-tests from the WISC-III were dropped: picture arrangement (a test for visual sequencing), mazes (a test for planning) and object assembly (a test for visual integration and attention to details). The subtests on the WISC tests the child's attention, abstraction, visual perception and visual memory. The entire WISC takes 65 to 80 minutes, though the time may change depending on whether the practitioner is administrating all of the subtests, or if the child needs a break in between the subtests.
Besides testing the child's IQ, the WISC is also used to test for learning disabilities, such as attention deficit hyperactivity disorder (ADHD). Since many of the subtests require the child to use sustained attention, deficits can be noted during testing. The subtests of the WISC are also timed, which can indicate if a child has a problem with a specific cognitive problem.
However, the WISC is not a fail proof method for ADHD testing, as noted by the "Psychology in the School" article “Discriminant and Predictive Validity of the WISC-III ACID Profile Among Children with Learning Disabilities" by Watkins, Kush and Glutting. The authors note that “ACID profiles were more prevalent among children with learning disabilities than among nondisabled children. However, when ACID profiles were used to classify students into disabled and nondisabled groups, they operated with considerable error." This particular study was done on the WISC-III, before the changes made to the most recent edition. Nevertheless, while the WISC can note possible cognitive deficits in a child, a combination of tests may be used along with the WISC to comprehend fully the child's strengths and weaknesses and provide a better picture of how she can perform academically.
Nova Southeastern University: Wechsler Intelligence Scale for Children — 4th Edition, http://cps.nova.edu/~cpphelp/WISC-4.html
Watkins, M.W., Kush, J.C., Glutting, J.J. "Discriminant and Predictive Validity of the WISC-III ACID Profile Among Children with Learning Disabilities." Psychology in the Schools, 1997