New findings in ADHD

Main Category: ADHD
Article Date: 19 Dec 2003 - 0:00 PDT


Attention deficit hyperactivity disorder (ADHD) is a commonly diagnosed neurobehavioral disorder, affecting between 3 percent and 5 percent of children in the United States.

The classic symptoms of ADHD are difficulties in maintaining attention, high distractibility, a tendency toward disorganization, and impulsivity-hyperactivity, leading to characteristic problems at home or at school. ADHD is the most common cause for referral for special programs or medication-based behavioral management.

Children with ADHD are always on the go. Asked to sit still and they will visibly squirm in their seats. The term, 'motor mouth' is sometimes used to describe a nonstop quality in their verbal behavior. Finding tasks that require planning or sustained attention a chore, kids with ADHD are likely to try to avoid them.

Easily distracted, the ADHD child is unable to stay tuned to mentally challenging tasks, flipping back and forth from one barely related thing to another. As a result of these and other symptomatic concerns, assignments are often incomplete, grades suffer, and social connections and subsequent social adjustment can be impaired.

In some cases ADHD seems to run its course, as children get older they might become less hyperactive. Still, adults might continue to present with many of the symptoms they had as children, with particular difficulties staying focused and finishing assignments.

Well-adapted adults will probably have chosen occupations and hobbies that make the most of their personal abilities (one can have ADHD and still have a high IQ) and where their attentional deficiencies are less critical.

While our understanding of the causes of ADHD is incomplete, we do know that it tends to run in families, especially among first-degree relations. Some ADHD symptoms may be due to other conditions, such as anxiety, depression, or other medical causes.

In a recent issue of The Lancet, Elizabeth R. Sowell and colleagues at the UCLA Laboratory of Neuro Imaging and Columbia College of Physicians and Surgeons published the results of a study detailing the neuroanatomical physical causes of ADHD.

Using high resolution magnetic resonance imaging (MRI) and surface-based computational imaging analytic techniques, Sowell's study provides us with a more precise specification of the sites involved in ADHD than ever before.

Previous structural imaging and post-mortem studies on ADHD have found reductions in brain volume, in the right frontal lobe (in the front of the brain, center for cognition, planning, etc.) and the caudate nucleus (part of the basal ganglia, located deep within the cerebral hemispheres; this area coordinates with the frontal lobes and other brain areas to regulate physical movements).

Taken together, these areas are where cognition and intentional movement functions are wired together. 'We see brain-size reductions in the ventral dorsolateral frontal lobes, (in the front, to the side) and the anterior temporal lobes,' Sowell said.

She also found increases in gray matter in the posterior temporal (on the side, toward the back of the ears) and inferior parietal cortices in the ADHD children studied. The significance of this study is that we now know more precisely where the primary brain-based effects of ADHD are located -- where the malfunction is, so to speak.

'Our results suggest,' Sowell said, 'that the disturbances in prefrontal cortices are localized to more inferior aspects of prefrontal regions than was previously appreciated.'

That the abnormalities occurred bilaterally, on both sides of the brain, was another new finding. In our search for effective treatments for disabling neurological and psychiatric disorders, it is vital that we gain in diagnostic skill as well as treatment effectiveness.

Having located the specific brain structures involved in ADHD, we can now better study and refine how our treatments, such as medications and behavioral training in this case, can lead to the real desired outcomes: better lives for patients and their families.

Allan J. Comeau, Ph.D., is a licensed psychologist on the clinical faculty at UCLA and a former president of the Inland Southern California Psychological Association. Write to him at 2001 S. Barrington Ave., Suite 304, West Los Angeles, CA 90025. Visit his Web site at www.drcomeau.com E-mail questions may be directed to yourmindmatters@hotmail.com.

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