ADHD: Does it really exist? Part II

January 14, 2008

—Nina Pierpont, MD, PhD

I talked, above, about diagnosing Attention Deficit Hyperactivity Disorder (ADHD), look-alike problems, and how young children learn to regulate themselves.  Now let’s consider older children.

Not all children with attention deficit disorders think or act the same way.

The regular medical criteria divide attention disorders in two:  those with hyperactivity and impulsive behavior, and those without.  (I will use “ADHD” as a shorthand to mean attention deficit disorders in general, both with and without hyperactivity.)

People with ADHD have trouble with mental energy.  Mental energy is literally the energy the brain uses for thinking.  The brain burns chiefly glucose (a sugar) and consumes oxygen, both delivered by the bloodstream.  When researchers do imaging studies (such as PET scans), they find that the brains of people with ADHD take up less glucose from the bloodstream than brains of people without ADHD.  The glucose is present, but the ADHD brains don’t use as much of it.  As a result, these brains get tired more easily. Thinking is just too much work.

Mental energy includes four “controls”:  energy for receiving information (called alertness), energy for doing mental work (called mental effort), consistency, and sleep control.

Receiving information takes energy.  A person has to listen, focus on the right things, register the right things in memory, screen out distractions.  It’s not a passive process.  When there is more detail, more volume, it takes more energy.

It’s amazing what children will tell you if you listen and watch.  “My brain hurts,” I hear, after putting them through tasks with a lot of verbal detail.  They yawn and look tired.  But a minute later, with a change to physical or hands-on tasks, or, even better, to play, all signs of tiredness vanish.

Children like this need breaks, snacks, and to move around.  Short snippets of work, interspersed with breaks, work better.  Homework, for example, can be done with a timer:  10 minutes of work, followed by 5 minutes of break for riding a bike or bouncing on a trampoline, and back for another 10 minutes of work.  Don’t use TV or computer games for the break, though!  They are too distracting, and don’t restore mental energy in the same way.

The consistency and sleep controls are also important.  Sleep problems are common in children with ADHD, not only from medications.  Attention problems may be worse the day after a poor sleep.  The first child I saw after learning about the controls was an articulate, frustrated third grader.  He told me, without any prompting, that some days he could remember his math facts easily and some days he could barely remember them at all.  He didn’t understand it, and it made him mad.  He knew what kind of day it would be from how he had slept the night before.  He had told this to his teacher and principal (where he often ended up, because he was disruptive when frustrated), but they didn’t credit what he said, not having heard of these problems.  This child was so validated by finding out he was right that he stopped misbehaving, weeks before starting a medication.  He started sleeping well, because mom got strict about bedtime and quiet in the house.

Problems with the consistency control are common.  Mental energy may not flow smoothly in children with ADHD.  There are gaps in alertness:  a child gets most of what is presented, but misses some critical details.  In testing, I see a “winking in and out” pattern.  The child is clearly with me and paying attention with all his might, but some details still slip by, in a random pattern.  Repetition helps.  On the output side, there may be random patterns of errors in work, or success at harder items rather than easier ones.  For this, re-checking helps.  So do separate steps for paying attention to certain details—for example, highlighting the operational signs before starting a page of arithmetic.

Next time, Part III, the processing controls, or why information goes “in one ear and out the other.”