Question:

A psychologist concluded that ADHD was strongly supported due in part by scores on the following academic assessments:

I am concerned that the psychologist is drawing conclusions between two different tests, while similar, may be assessing different things, in addition to norms not being the same.

Do the statistical correlations between these two assessments demonstrate a sound comparison of skill level?

I understand that test results may vary greatly with students with ADHD. Were the above scores a demonstration of this characteristic?

Maureen

Answer:

Dear Maureen,

I am concerned that your letter may not include all of the information that the psychologist used to make the diagnosis. However, academic test scores alone definitely are not adequate to diagnose a student with ADHD.

Both the formal tests that you cited are “norm referenced” academic assessments. They are designed to measure academic achievement - defined as those skills and information that a student acquires in an academic setting in relationship to a student’s peers nationwide. Neither of these assessments purport to measure ability, aptitude, or cognitive processing. The manual for the WJ-III Tests of Achievement (WJ-III ACH) indicates that “An examiner can use the WJ-III ACH to determine and describe the present status of an individual’s academic strengths and weaknesses. Additionally, test results help determine how certain factors are affecting related aspects of development. For example, a weakness in phoneme/grapheme knowledge may interfere with overall development in reading and spelling.” Diagnosing mental disorders is not listed as a use for the WJ-III ACH.

The Wechsler Individual Achievement Test, Second Edition (WIAT-II) has a similar purpose. The manual for the WIAT-II states, “The WIAT-II is a comprehensive, individually administered test for assessing the achievement of children, adolescents, and college students… The WIAT-II measures aspects of the learning process that take place in the traditional academic setting in the areas of reading, writing, mathematics and oral language.”

In contrast, ADHD is classified as a “disruptive behavior disorder” in the Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV). ADHD is described as “a persistent pattern of inattention and/or hyperactivity-impulsivity that is more frequently displayed and more severe than is typically observed in individuals at a comparable level of development.” All of the criteria described are observable behaviors. Nothing in the criteria for ADHD indicates that the level of academic achievement, advanced, delayed or normal, is involved in the disorder.

Children who have ADHD often demonstrate characteristics that may be evident in their academic work. For example, one of the criteria in the DSM-IV suggests that child with ADHD, Inattentive type “often fails to give close attention to details or makes careless mistakes in schoolwork, work or other activities.” These careless errors may be evident in a student’s responses on either the WJ-III or the WIAT-II, but neither of these assessments provides a means to measure any degree of carelessness in order to diagnose ADHD.

The WIAT-II Examiner’s Manual reports that the assessment was administered to a sample of individuals diagnosed with ADHD and the results were compared with a control group. All means were in the expected range for individuals with ADHD. Although the means were within the average range, lower scores were reported on the Written Expression and Spelling subtests than in other areas.

The WJ-III has a cognitive component called the Tests of Cognitive Abilities (WJ-III COG). Some of the subtests in this battery may be useful for diagnosing ADHD but none is sufficient unto itself. The WJ-III Technical Manual cites research done to indicate that certain WJ-III COG subtests may correlate from slightly to moderately to other measures of attention. However, your question does not mention any WJ-III COG subtests. Whether WIAT-II scores correlate with WJ-III ACH scores is not relevant to the potential diagnosis of ADHD.

In summary, please refer to the link to “Previous Questions” at the Ask a Specialist website, for a complete description of what to look for in an assessment for ADHD. The response describes the guidelines for ADHD assessment published by American Academy of Pediatrics. These guidelines are a good place to start to evaluate if the assessment your child is receiving is thorough and appropriate.

References

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision. (2000) Washington, DC: American Psychiatric Association.

Mather, N. and Woodcock, R. (2001) Examiner’s Manual. Woodcock-Johnson III Tests of Achievement. Itasca, IL: Riverside Publishing

McGrew, K and Woodcock, R. (2001) Technical Manual. Woodcock-Johnson III. Itasca, IL: Riverside Publishing

WIAT-II Examiner’s Manual . San Antonia, TX: The Psychological Corporation (2002)