Testing For Attention Deficit Hyperactivity Disorder

How does one go about testing for ADHD?  Ideally, there will be multiple viewpoints and data sources.  The major data viewpoints are:

• clinical interview with patient and parents, if the patient is a minor
• some basic measures of depression and anxiety (these have to be ruled out as causes of ADHD)
• some rating scales to be completed by the patient
• rating scales to be completed by the parent or spouse
• rating scales to be completed by teachers
• a computerized test of attention (vigilance)
• sometimes, an IQ test (more about this below)

Let's take these one at a time.

The clinical interview is absolutely necessary.  It is important to hear what a patient has to say, and it is also important to observe their behavior.  I usually conduct a full clinical interview.  That is, I don't just assume that the problem is ADHD.  I ask about all typical areas of childhood problems, including depression, anxiety, psychosis, and even eating disorders.

When it comes to the ADHD symptoms specifically, I ask the child first what their thoughts are about a symptom (e.g., "Do you have a problem keeping your attention going in class?") and then ask the parent for their opinion, so that I have both perspectives.

I use a self report depression inventory and a children's anxiety inventory, which I read to them.  Depression and anxiety can cause attention problems.  I also want to know if their ADHD is causing them to have low self-esteem or depression.

If the child is a teenager or older, I use a self-report ADD questionnaire.  There are ADD questionaires for children, but generally I only use self-report questionaires for teenagers and adults.  I use the Brown ADD Self Rating Scale for ADD.

I also use the Behavior Rating Inventory for Executive Functioning.  This measures executive functions, which I have written about elsewhere.  It measures nine different types of executive functions. 

• Problems with self-monitoring (being aware of how one is acting and how it is affecting others)
• Problems with initiating tasks
• Problems with working memory (being able to keep things in short term memory to perform actions on them, such as remembering a phone number from the time of reading it in a directory to the time of dialing)
• Problems with planning and organizing time
• Problems with task monitoring (being aware of whether a strategy on a task is working)
• Problems with organization of materials
• Problems with inhibiting impulses–causing acting out and impulsivity
• Problems with shifting from one task to another when needed or shifting from one problem solving strategy to another when one is not working
• Problems with controlling and modulating (smoothing out) emotions

I use the Conner's Continuous Performance Test-II to measure vigilance over a 15 minute period of time.  The Conner’s Continuous Performance Test-II is a computerized test of attention which lasts approximately 15 minutes. It does not measure brief bursts of attention (as measured by some of other types of tests); rather it measures the ability to continue to attend to a simple vigilance task over a period of time.
I use the WISC-IV or WAIS-IV to measure IQ.  I am not really all that interested in IQ.  IQ is in my opinion an oversold concept.  The full scale IQ of someone is not nearly as interesting as understanding what their strengths and weaknesses are.  The Wechsler scales have four major indexes and a minimum of ten subscales.  I want to know if the child's IQ accounts for their problems in school.  I also want to know if they are showing any problems with working memory.  Other items of interest on the WISC or WAIS are the comprehension subtest, measuring social comprehension and the processing speed subtests.

Sometimes, a measure of intelligence is needed, particularly if there has been poor school performance. However, the IQ measure does not really tell us much about whether ADHD is present. Instead, it helps us to know whether the child is underperforming in school, or whether poor grades are perhaps due to something else. Sometimes, a learning disorder is thought to be present, and an achievement test may be needed. Usually, learning disorders are diagnosed by comparing achievement testing with IQ tests. Learning disorders are often present in ADHD. However, ADHD proper does not need IQ tests or achievement testing for diagnosis.

Is It ADHD--Or Is It Anxiety--Or Is Depression?

In psychology and psychiatry, we are almost always presented with the issue referred to as differential diagnosis.  There is often more than one diagnosis which can explain a set of symptoms.

For example, with ADHD, there are deficits in attention and other aspects of executive functioning.  However, these deficits can be caused by many reasons.  Some of the most typical causes (besides ADHD) are depression and anxiety.

In depression, if it is severe enough, the brain is not working at maximum efficiency.  In fact, it is like a car trying to go up a hill when three out of six spark plugs are not working.  There just isn't the power to do what it needs to do.  Concentration and memory consolidation are affected.

For an example of a pet scan in depression, go to http://www.mayoclinic.com/health/medical/IM00356
(Pet scans are like an xray of the brain.  However, instead of revealing structure, they reveal activity levels.  They show the level of glucose utilization.  Red and orange areas show high levels of glucose utilization, hence indicating higher levels of brain activity.  Purples and blues indicate lower levels of brain activity.)  In the petscan at the Mayo Clinic link, you can see how the brain which has recovered from depression is more active than the brain in a state of depression.)

In anxiety, the person has a hard time concentrating.  They may feel fuzzy headed, or they may be distracted by their worries.  This interferes with attention, and when there is impaired attention, it is hard to learn.

Of course, it is quite possible that a person will have both depression and ADHD, or anxiety and ADHD.  Depression, at least in a mild form, is often a result of ADHD in children and teenagers because they are not doing well in school and perhaps not being accepted by their peers.  On the other hand, the more severe that the depression is, the less likely it is to be explained by depression, and the more we have to start looking at other causes.