by Al Galves, Ph.D.
A careful reading of this CNN article about brain differences related to ADHD tells me that nothing in it will be very useful to human beings. The article reports on a study that finds that persons diagnosed with ADHD have smaller parts of the brain, which are related to the processing of emotions. How, pray tell, is this going to be useful to human beings?
We don’t have any psychotropic drugs or any forms of psychosurgery that can be used to improve the emotional processing of human beings. We have drugs and psychosurgery that can dull emotions or artificially enervate emotions but we don’t have any drugs or psychosurgery that can help people do a better job of learning from their emotions or using them in beneficial ways.
On the other hand, psychotherapy can and regularly does help people learn how to use their emotions in beneficial ways. And psychotherapy does this without causing the kind of harmful “side effects” that are associated with psychotropic drugs and psychosurgery.
Although it isn’t explicit in saying so, this article implies that ADHD is a result of smaller brain structures in areas that process emotions. There is no evidence of that being the case. All we have is a finding of correlation between smaller brain structures and ADHD. That is not evidence that such brain anomalies cause ADHD. It is merely a correlation, and a small one at that. Knowing what we know about the stress response in humans it is more likely that the behavior and state of being related to diagnoses of ADHD is causing the brain anomalies than the other way around.
Plus, as is typical of the claims in these studies, the claim is not supported by the data. The largest brain region difference reported in the study was with the amygdala. The difference between the ADHD and non-ADHD groups’ was a Cohen’s d of .19. But this is such a small difference in the group averages that the groups overlap so much that most people in the ADHD group don’t have the claimed smaller amygdala than those in the non-ADHD group. How can this be if the title reads, “Brains of those with ADHD show smaller structures related to emotion”? See the display below, which shows an even larger Cohen’s d of .20. The ADHD group would be the darker one.
In stating that ADHD is a neurodevelopmental disorder, the article tells an untruth. There is no scientific reason to believe that ADHD is a neurodevelopmental disorder. ADHD is diagnosed through observations of certain behavior, not brain scans. There can be many reasons for such behavior, including concern about being abused or mistreated at home, not being able to do the work being assigned in school, being bored in school, not caring about what is being focused on in school, being frightened by an abusive teacher, etc., etc., etc. Neurodevelopmental anomaly is only one of many explanations for the behavior associated with a diagnosis of ADHD, and it is a poor one. In order to call it a neurodevelopmental disorder, one must first show evidence of a neurodevelopmental defect, and that has not been done.
In closing, although the author of the article and the authors of the study may believe they have a finding which is useful to human beings, such is not the case.