Neuropsychologists in the evaluation of ADHD

Recently, the media has reported that the American Academy of Pediatrics (AAP) has broadened its 2000-2001 guidelines for the diagnosis of and treatment of ADHD. While the prior guidelines focused on children from ages 6 to 12, the new guidelines cover ages 4 to 18. The story is being covered by the media with lead-ins such as saying that AAP is “expanding the age range for diagnosis and treatment.”

This is technically not true.

The fact is that the diagnostic criteria for ADHD have already been in existence in the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (Text-Revision), referred to as DSM from this point forwards. This is the book, published by the American Psychiatric Association, which mental health and medical professionals refer to for making diagnostic decisions in this particular subject area.

There is nothing in the already existing ADHD criteria in DSM that prevents a diagnosis of ADHD in a four-year-old child. While the DSM mentions that it is difficult to establish the diagnosis before age 4 or 5, there is nothing that states the diagnosis cannot be made at age 4 (or earlier). In fact, part of the DSM criteria for ADHD is that the symptoms should be present before age 7, although this has been a subject of debate and will reportedly be changed to a higher age level in the next edition of DSM due out in 2012.

What AAP is really suggesting here that is new is that pediatricians should initiate evaluations of ADHD at age 4 if the child has academic or behavioral problems and symptoms of inattention, hyperactivity, and impulsivity. The new guidelines state that “primary care clinicians” should determine if the DSM criteria are met (which means the problems need to be present in more than just one setting, not only in school or only home).

While these guidelines are laudable, I am left to wonder how primary care clinicians (e.g., pediatricians, nurse practitioners) are going to be able to do this given the combination of time-limited visits and a very busy schedule. It is important to keep in mind that according to DSM criteria, there are 9 inattention symptoms, 6 hyperactivity symptoms, and 3 impulsivity for a total of 18 possible symptoms to cover with the parent. Some parents tend to go into a lot of detail when discussing these items and so going over the criteria properly can be quite time intensive. The new AAP guidelines also say that the PCP should also interview teachers and other school and mental health clinicians involved in the child’s care to make the diagnosis. In an ideal world, this sounds great, but most PCPs simply do not have the time to do this.

Speaking of not having time to do things, the new guidelines state that the primary care clinician should rule out alternative causes besides ADHD. This is another good standard, consistent with DSM, but it is also very time intensive. Why? Because the list of possible reasons why a child can have academic, behavioral, and attention problems is very extensive. Psychological and psychosocial explanations (e.g., depression, anxiety, parental divorce, abuse) are possible explanations and the guidelines correctly state to assess these conditions as well as for developmental disorders such as learning disorders and language disorders. Physical explanation such as sleep apnea would also need to be ruled out.

While a primary care clinician can easily refer a patient for a sleep apnea study and order other tests to rule out a physical cause of ADHD-like symptoms, what primary care clinician is going to have the time to go over all 18 symptoms, interview teachers and other sources of information, evaluate for a learning disorder, and evaluate for psychological causes of the symptoms? None who I know of. For example, evaluating for a learning disability is going to require time intensive psychological testing and primary care clinicians simply do not administer IQ tests and test of academic achievement.

The AAP guidelines explicitly acknowledge the time limitations involved in these types of evaluations and the need for collaboration with mental health professionals. Who do they suggest referring such patients to for additional evaluations? Child psychiatrists, developmental behavioral pediatricians, neurodevelopmental disability physicians, child neurologists, or child or school psychologists. While I have no opposition to any of these professions playing a role in the diagnostic process, there is one major omission in these guidelines: the field of clinical neuropsychology.

Clinical neuropsychology is the field of psychology that studies the relationship between brain functioning, emotions, behaviors, and thinking. Considering that ADHD is a neurological condition affecting the brain that affects behaviors and thinking abilities, referring a patient for a neuropsychological evaluation is certainly something a primary care clinician should consider. Why? First, a neuropsychological evaluation involves the objective assessment of thinking, behaviors, and emotions. That is, the patient’s performance on tests of attention and impulse control, for example, is compared to groups of children the patient’s age with no history of neurological damage.

While some critics note that the testing results may not always generalize to real-world environments, the fact is that these tests are the only way to objectively assess the patient’s actual cognitive abilities outside of grades in the classroom on academic tests. Behavioral checklists can be used and scored but at the end of the day they are still measures dependent on subjective opinions and have their own set of limitations.

While it is true that the ADHD criteria in DSM do not require neuropsychological testing to make the diagnosis, neuropsychological evaluations are not only about testing. Neuropsychologists are able to spend far more time on a single case than a primary care clinician and thus they can do a more detailed evaluation of symptoms, perform a detailed review of medical and academic records, and perform detailed evaluation of possible co-morbid psychological disorders. Neuropsychologists are also experts in a wide variety of other neurodevelopmental conditions (such as learning disorders) that can masquerade as ADHD and thus the evaluations can rule out or rule in other possible causes that can lead to better treatment.

Admittedly, clinical neuropsychologists need to publish studies showing that diagnostic evaluations for ADHD improve outcome. Recognizing this need, the American Academy of Clinical Neuropsychology recently funded a study by Dr. Mark Mahone from Kennedy Krieger Institute and the Johns Hopkins University School of Medicine entitled “Incremental Validity of Neuropsychological Assessment in Identification and Treatment of ADHD.” We will await and see the results of this study.

In sum, families and primary clinicians should consider referring patients to clinical neuropsychologists in the development of ADHD. While neuropsychological evaluations have limitations, limitations also apply to the other professions who the AAP guidelines suggest referring patients to. The fact that not a single national neuropsychological organization was consulted in the development of these guidelines is troubling and one has to wonder whether the omission was purposeful. After all, it is not as if pediatricians and the school psychologists they consulted with have never heard of neuropsychologists. I will be contacting the AAP and request a response and will post the response if it is provided.