Diagnosing ADHD with Psychological Testing
Psychological testing as part of an evaluation for Attention Deficit Hyperactivity Disorder - ADD ADHD - can be helpful.
Tests such as the WISC-R, which is an IQ test, the Wide Range Achievement Test (WRAT), and the Bender-Gestalt test, which is a visual motor integration test, can be helpful within limits.
There are certain patterns of strengths and weaknesses that one might predict to find on these tests if the subject had ADHD. But it's as much art as science. The patterns are not "diagnostic" for Attention Deficit Hyperactivity Disorder. They just may be "consistent" with ADHD.
It's also important as a part of the evaluation to know the subject's IQ level. If the kid has a real low IQ, or a major learning disability shows up, it could be a clue that there is something else going on instead of attention deficit hyperactivity disorder.
So we find these tests helpful, but not specific for ADHD.
TOVA TEST for ADHD
The Test of Variables of Attention (TOVA) is the most helpful test that we found for the diagnosis and treatment of ADHD, but even it is never used in the diagnostic process without the interviews, rating scales, physical exam, or perhaps some other testing. But it is a good tool in the evaluation process.
The TOVA is an extremely boring computer test that requires the kids to respond to a target stimulus by pressing a button, or to not respond when there's a non-target stimulus.
The fact that it is so boring is a work of genius because it helps to differentiate between kids who have trouble with "boring," and kids who do all right with "boring."
The TOVA is really a valuable tool, but it should never be given just by itself. It needs to be given in the context of the whole diagnostic workup.
Getting a TOVA Baseline
TOVA is given with no medication in the diagnostic process. And part of its value is that if medication is considered at some point, the test can be re-administered with a "challenge dose" of medication in their system. This can tell the physician if the subject is a "responder" to that particular medication or not, or how well he responds to that particular dose of that particular ADHD medication.
Clinical Observation for ADHD at School
Clinical observation of the child is very important. If possible, ideally, somebody observes the child in the classroom.
In the real world, we don't know anybody in private practice who can go out in the classroom to observe a child these days, but if a school nurse or school psychologist can go observe them, it can be very, very helpful.
EEG and ADHD
Obtaining an EEG from a neurologist is rarely helpful in the process of diagnosing ADHD.
EEGs will show that there are differences between the brainwave patterns of those with ADHD and those without ADHD. Typically there is excessive slow brainwave activity, particularly in the Theta band (4-7 Hz.).
However, ninety-five percent of all Attention Deficit Hyperactivity Disorder kids have what the neurologist will call "normal" EEGs.
What we mean by "normal" is they don't have big epileptic seizure spikes, or indications of tumors or head injuries, that a neurologist would say are "abnormal."
But when compared side by side with a non-ADD person, the EEGs are much different if the subject has ADHD.
An EEG may be helpful if the child is going to be treated with EEG biofeedback, but in terms of being helpful for a diagnostic work-up, it is rarely helpful.
However, if the parent interview revealed that the child had some potential neurological problem, as seen in sleep walking, or a history of seizures, and so on, then an EEG would be a good idea.
Summary of Diagnostic Evaluation for ADHD
An adequate diagnostic interview, designed to give an accurate diagnosis a very high percentage of the time, while not costing the family thousands of dollars, would look like this:
- Physical Exam - Office Visit
- Clinical Interview - Parents (45-60 minutes)
- Clinical Interview - Child (45-60 minutes)
- TOVA test
- Parent and Teacher Rating Scales
- Office visit to review information and develop a treatment plan
- Other testing if there were still questions to be answered
- Begin Treatment
That's it! If there are further diagnostic questions, then more testing would be required. But in the majority of cases, this is all that is needed to make a highly reliable diagnosis.