Methylphenidate, Ritalin, and "Working Memory Functions" in ADHD

June 2007

Do Stimulants Have a “Reverse Effect” on People with ADHD?

Its one of the classic ADHD myths, that stimulants have a “reverse effect” on those with ADHD than on those without ADHD. How else can you explain that a non-ADHD person takes stimulants and gets “spun up” while a person with ADHD is actually on purpose treated with stimulants to make them “calm down”?

A recent study with MRI technology looked at how stimulant medications actually impact the brain in both those with ADHD and those without.

Children, teens, and adults with ADHD have problems with attention, self-control, and restlessness or hyperactivity. They also may show deficits in what is called "working memory functions."

These "working memory functions" are what maintain and manipulate the information that we take in from the world aroud us. This "working memory" is crucial for every-day functioning. Without it functioning well, we are total "space cadets."

Methylphenidate (MPH) is the stimulant medication that makes Ritalin, and a few other ADHD medications. It is a potent medication that may improve the performance in several areas of the brain, and in cognitive tasks.

Recently some researchers, using MRI technology, looked at the impact of MPH on "working memory functions" using a study group of six boys with ADHD, and also six boys without ADHD.

Each subject was tested twice, once with Methylphenidate in his system, and once without. During imaging in the MRI Scanner, all participants performed a working memory task that became increasingly difficulty.

The results of the EASIEST task showed no differences between the groups of boys, or whether they had medication or not. Everyone did pretty well on the easiest task with or without MPH.

But in the MORE difficult task, the ADHD subjects performed better when medicated than they did without medication. And with the MPH the fMRI images showed increased activity in the frontal regions of the brain. This is consisten with what is known about stimulants.

In the MOST difficult task, performance of medicated patients was better than that of non-medicated patients.

Likewise, brain activation increased under medication, especially in frontal and parietal regions of the brain. These areas are thought to be involved in "working memory processes." These specific activation patterns in the ADHD boys with medication were very similar to the patterns seen in the boys without ADHD, also with medication. In other words, stimulants have the same effects in the brains of people with ADHD, and without ADHD.

The study also indicated that MPH improves the "functional networks of working memory" by increasing the brain activity in parietal and frontal regions. It also pointed out that the improvement is best seen in difficult tasks.

It also shows that MPH does not have some kind of "reverse effect" on people with ADHD, as some myths claims. Rather, the MPH activation patterns are similar to the ones observed in the healthy boys. All the stimulant medication does is improve the performance of certain regions of the brain so that the brain functions more normally, and is better at focusing, problem solving, and having self-control.

Of course, we would rather that you try an alternative solution to stimulant medications for the treatment of ADHD, and our recommendation is Attend by VAXA. It is not quite as effective as Ritalin - see our comparison - but it does work very well and has no harmful side-effects.

The Organization for Human Brain Mapping is located in Minneapolis, MN.