Students in Dr. Harvey’s class, HDFS 310, Infant & Child Development in Context, here are the sources for my handout, and some relevant links.

Definitions and Background

Criteria for ADHD as given in the Diagnostic and Statistical Manual of the American Psychiatric Association, Fourth Edition (DSM-IV), modified by the Centers for Disease Control (CDC) “to make them more accessible to the general public.”

Here are the unmodified DSM-IV Criteria.

Incidentally, CDC also offers epidemiological information.

Here’s an excellent single-site source on all aspects of ADHD.

And here is more than you want to know about ADHD from the National Institute of Mental Health.

An Executive Function perspective on ADHD

From CHADD’s ATTENTION Magazine, here’s an explanation of
5 Components of Executive Function.

Thomas Brown’s Executive Functions Impaired in ADD Syndrome

ADHD as Executive Function Impairments gives a simplified version of Brown’s views.

For my money, the most powerful theorist about ADHD is Russell Barkley. He isn’t an easy read, but this source presenting Barkely’s views will repay the effort.

Here’s Adele Diamond’s argument that we need to separate ADHD and ADD.

My fundamental points from yesterday evening’s talk:
* The ways we can look at learning interferences are tangled together in multiple ways.
* Common sense may be our best tool to untangle them.

One of the pleasures of preparing to speak to a group is that it encourages the speaker to do some catching up. I came across a concept – new to me, although it has apparently been around for a couple decades! – that seems to be a tool to think better about ADHD: Endophenotype. Since I could barely mention the idea in the time I had, I thought it would be fun to post about it here, so I can try to find words to describe it. I should start by saying this is all new to me this last weekend. I have no background in genetics, so this is a layman’s attempt to understand.

You know that “ADHD” is a complex entity. The diagnostic manual, DSM-IV, gives us three subtypes: predominantly inattentive, predominantly hyperactive / impulsive, and combined. Recently, we’ve seen convincing evidence that Inattentive Type ADHD probably reflects “different wiring” – has different genetic origins than the classical Combined Type. But that’s only the start: Anyone who is ADHD, or is working to help an ADHD person grow and develop, knows that no two people show their ADHD in exactly the same way. That’s leads to the notion of a phenotype: the individual expression of a particular genetic inheritance, modified by a particular environment – by a particular personal history.

There’s a lot of evidence that what we clump together under the ADHD diagnosis doesn’t come from a single genetic wiring. The individual genetic complex that we’re born with is our genotype – a blend of the genetic potentials of our parents. If we could get back to the genetic underpinnings of different ADHD individuals, if we could sort out the different wirings we call ADHD, get back to the different genotypes we clump together as ADHD, it could have huge benefits. It might mean that we could detect ADHD very early. It might mean that we could eliminate the current “guessing game” of finding the effective medication for an individual. (Put that the other way around: We have to try this medication and that because different ADHD people, with different “wirings,” will respond to different medications, and right now, we don’t have a way to differentiate those different wirings.)

But that clumping together of different wirings makes it difficult to get to the genetic underpinning, in at least two ways. First, when researchers study a group of “ADHD” children, the sample probably includes many different genotypes. Second, the terms we used to diagnose people don’t relate clearly to the fundamental wirings: What could be the genetics that underlie “Fails to give close attention to details or makes careless mistakes"?

That brings us to Endophenotype. The idea is simpler than the word: Can we find things which we know are part of what we call ADHD, which we know how to measure, and which are closer to the genetics that structured the basic wiring than are the words of our diagnostic definition? If we can identify those, then we can identify the genes involved in them. For example, we know that working memory is an important part of ADHD. We know how to measure working memory. And there’s evidence that working memory ability is heritable, that it has a genetic basis.

Here’s how Irving Gottesman explains the idea

An endophenotype may be neurophysiological, biochemical, endocrinological, neuroanatomical, cognitive, or neuropsychological (including configured self-report data) in nature. Endophenotypes represent simpler clues to genetic underpinnings than the disease syndrome itself, promoting the view that psychiatric diagnoses can be decomposed or deconstructed, which can result in more straightforward—and successful—genetic analysis. However, to be most useful, endophenotypes for psychiatric disorders must meet certain criteria, including association with a candidate gene or gene region, heritability that is inferred from relative risk for the disorder in relatives, and disease association parameters. In addition to furthering genetic analysis, endophenotypes can clarify classification and diagnosis….

Now, you and I don’t care about the genetics themselves. We care about helping individuals. And no one has begun to understand what all the endophenotypes are. But maybe we can think better about what ADHD means to us or our loved ones if we can get to some of these measurable candidates. For me, I may be able to design more focused evaluation. For parents and teachers, we may be able to focus our interventions better.

Gottesman suggests three criteria for candidate endophenotypes. Here are my top-of-the-head candidate endophenotypes for ADHD. I think all of these meet at least two criteria: they can be measured, and they have a degree of heritability. The third criterion, I don’t have the background to judge, so I’m purely guessing that they may be able to be associated “with a candidate gene or gene region.” I’m going to start looking for good ways to measure these concepts, so we can think about ways to either work on the skills involved, or on accommodations to work around deficit areas.

Working Memory

Processing Speed

Perception of time

Any help thinking about candidates is much appreciated.

My two previous posts, on the role of frontal lobes in adolescence, are background to this.

The impetus to those two posts was to provide background to an article,
New Study Gives Hovering College Parents Extra Credit, which appeared in the Washington Post on November 5.

Data from 24 colleges and universities gathered for the National Survey of Student Engagement show that students whose parents were very often in contact with them and frequently intervened on their behalf “reported higher levels of engagement and more frequent use of deep learning activities,” such as after-class discussions with professors, intensive writing exercises and independent research, than students with less-involved parents.
“Compared with their counterparts, children of helicopter parents were more satisfied with every aspect of their college experience, gained more in such areas as writing and critical thinking, and were more likely to talk with faculty and peers about substantive topics,” said survey director George D. Kuh, an Indiana University professor.

The study attracted attention because it goes against an assumption that when someone leaves for college, parents should butt out. What I especially like is that it isn’t generalized parent involvement the study seems to describe, but support for executive functioning:

The study says that 13 percent of first-year students and 8 percent of seniors reported having a parent or guardian who “frequently intervened on their behalf to help them solve problems they were having at the college.”

Bottom line? This is all about “downloading some frontal lobe.” I’ve talked to a couple college students since this came out, and they are clear about what’s helpful. It isn’t calling up to nag that helps. It’s good advice – the sort of executive-function support that a developing frontal lobe still needs.

If you haven’t read the post just below, “Frontal Lobes,” please start there.

We don’t develop a fully adult frontal lobe until the early twenties. This means that teenagers have to handle the most dangerous time of their lives without a fully functional CEO. Impulse control, anticipation of consequences, the ability to make and hold a plan of action – their brain isn’t yet entirely wired to handle those executive functions.

When teens blow it? What they just did – it was about brain wiring. To demand fully mature problem solving and decision making from a teen brain is like insisting to a six-month baby that she could ride a bike if she only tried harder.

Although I haven’t seen anyone say it, it seems to me that a simplistic definition of adolescence is that it’s the period from pubescence, with its rush of tough-to-manage hormones and body changes, until the frontal lobes mature and can take control.

Adolescence terrifies us parents most when we see that our precious half-child is about to (or just did) something dangerous, destructive, harmful to their future. But when we try to come to the rescue, what happened to “Thank you, Mommy / Daddy"? Repulsed and wounded, we try to control, we nag, we accuse… And if you’ve been there, you know how well that works.

I love the reframe the fMRI research exemplified by Jay Giedd allows when I talk to parents and kids. Teens are willing to hear about brain research that says this important brain function isn’t all there yet. They aren’t being stupid or irresponsible when they blow it. And parents can see that kids aren’t trying to screw up. The part of their brain that could have helped isn’t quite online yet.

The reframe has a major implication. Pointing towards the front of my head, I say to kids, “So picture yourself with a USB port about here. If you don’t have a full-grown frontal lobe yet, you sometimes need to download some frontal lobe. And there’s a full-grown frontal lobe sitting right next to you.” Making it about neurology, about development, takes the embarrassment out. You didn’t screw up because you wanted to, or because you’re stupid. Your brain just wasn’t ready to think things through. But that’s a problem. Sometimes, you need some support. You need to talk to someone who has been there, and figured it out, and can see the pitfalls and help you plan good actions. Sometimes, you need to download some frontal lobe.

If you are the parent of an adolescent, you need to be familiar with one fact about the teenage brain. Jay N. Giedd, of the National Institute of Mental Health says, in an article, Structural Magnetic Resonance Imaging of the Adolescent Brain

The dorsal lateral prefrontal cortex, important for controlling impulses, is among the latest brain regions to mature without reaching adult dimensions until the early 20s.

Here’s my version: The CEO of the brain, the part that controls impulses, plans and holds to a course of action, helps us anticipate consequences, and in general helps us “act like adults” isn’t fully developed until well after the teen years.

Here’s Jay Giedd again:

The frontal lobe is often called the CEO, or the executive of the brain. It’s involved in things like planning and strategizing and organizing, initiating attention and stopping and starting and shifting attention. It’s a part of the brain that most separates man from beast, if you will. That is the part of the brain that has changed most in our human evolution, and a part of the brain that allows us to conduct philosophy and to think about thinking and to think about our place in the universe. …
I think that [in the teen years, this] part of the brain that is helping organization, planning and strategizing is not done being built yet … [It’s] not that the teens are stupid or incapable of [things]. It’s sort of unfair to expect them to have adult levels of organizational skills or decision making before their brain is finished being built. …

Although I want to focus the frontal lobe aspects of Dr. Giedd’s work, his conclusions are far reaching and sometimes enormously optimistic. Here’s an article that embeds the frontal-lobe thread in his more general work with the non-adult features of the adolescent brain. And here’s the always-excellent Sharon Begley, also in the larger context: Getting Inside a Teen Brain

This research gives us the most important new knowledge about the teen brain since I was a teen myself, just before the last mastodon kicked off. In my next post, I want to talk about how I use this new knowledge in my own practice. Then, I want to comment on an article about “helicopter parents” that appeared last week.