From the NYT sensational article on ADD ADHD
This is the thing that startled me:
Psychostimulants like Adderall and Ritalin help by blocking the transport of dopamine back into neurons, thus increasing its level in the brain.
I’d understood that the stimulants work by increasing the release of dopamine and norepinephrine.
When I looked this up on the net, I found studies supporting both effects, including contradictory studies from Dr. Volkow.
What’s a poor boy to do? I’m sure, or at least hopeful, that some of you out there can clear this up?
Dr. Nora D. Volkow, a scientist who directs the National Institute on Drug Abuse, has studied the dopamine reward pathway in people with A.D.H.D. Using a PET scan, she and her colleagues compared the number of dopamine receptors in this brain region in a group of unmedicated adults with A.D.H.D. with a group of healthy controls. What she found was striking. The adults with A.D.H.D. had significantly fewer D2 and D3 receptors (two specific subtypes of dopamine receptors) in their reward circuits than did healthy controls. Furthermore, the lower the level of dopamine receptors was, the greater the subjects’ symptoms of inattention.
Yes, we are little different aren’t we?
If you don’t want to wade through these, I’ll summarize them in another post.
Aaron T. Mattfeld, a neuroscientist at the Massachusetts Institute of Technology, now at Florida International University in Miami, compared the brain function with resting-state M.R.I.s of three groups of adults: those whose childhood A.D.H.D persisted into adulthood; those whose had remitted; and a control group who never had a diagnosis of it. Normally, when someone is unfocused and at rest, there is synchrony of activity in brain regions known as the default mode network, which is typically more active during rest than during performance of a task. (In contrast, these brain regions in people with A.D.H.D. appear functionally disconnected from each other.) Dr. Mattfeld found that adults who had had A.D.H.D as children but no longer had it as adults had a restoration of the normal synchrony pattern, so their brains looked just like those of people who had never had it.
But from MIT
In people without it, when the default mode network is active, another network, called the task-positive network, is inhibited. When the brain is focusing, the task-positive network takes over and quiets the default mode network. This reciprocal relationship is necessary in order to focus.
Both groups of adult A.D.H.D. patients, including those who had recovered, displayed simultaneous activation of both networks, as if the two regions were out of step, working at cross-purposes. Thus, adults who lost most of their symptoms did not have entirely normal brain activity.
So, if we lose most of our symptoms, like in a perfect work or school environment, our brains still function differently.
The NYT article – What?? You haven’t read it yet?!