Aug. 24, 2001 (San Francisco) -- Every child is unique. So is every case of attention deficit hyperactivity disorder, or ADHD. New insights -- reported here at the annual conference of the American Psychological Association -- now promise an end to one-size-fits-all ADHD treatment.
"We are trying to trigger a little bit more thinking about what is ADHD," says University of Toronto researcher Rosemary Tannock, PhD. "In the future we will need to consider the nature of ADHD impairments before starting treatment. We'll never find a single deficit that encompasses all ADHD."
This has made it hard for some parents to accept that their child has ADHD, says Yale University researcher Thomas E. Brown, PhD. Even the same child doesn't behave like the same child all the time.
"One thing that makes people skeptical is that the symptoms are not constant," Brown says. "It is very unusual for an ADHD person to display the same symptoms in all settings. Some people say it is just a willpower thing. But what looks like willpower really has to do with neurochemical processes in the brain."
"Picture a symphony orchestra where all the musicians are good," Brown says. "But if the conductor cannot get them to play their respective parts at same time, you are not going to get very good music. The problem with ADHD is not with the individual musicians. The problem is essentially with the conductor."
The brain's conductor has to do a lot of things at the same time. These things include:
- Activation: To perform a task, the brain first has to get things started.
- Focus: To carry out a task, a person has to be able both to keep focused and also to shift focus when necessary.
- Effort: The brain has to regulate alertness and keep up the speed at which the task is performed.
- Emotion: The brain has to be able to turn up or turn down the emotions felt while performing a task.
- Memory: The brain has to store things into memory and pull things out of memory.
- Action: The brain has to be able to keep track of what is going on and keep actions under control.
Ritalin, the safest and most effective drug used to treat ADHD, clearly exerts an effect on these executive actions. Recent studies from the Brookhaven National Laboratory show that people with ADHD overproduce a kind of scavenger that removes an important brain chemical. Ritalin blocks these scavengers.
Unfortunately, Ritalin wears off after a few hours. Moreover, second and third doses given in the same day have to be larger than the first dose. This is one problem with the drug -- it may not be working most effectively at the time a child needs it the most.
New once-a-day formulations deliver the drug found in Ritalin in a way that smoothes out the peaks and valleys that come from three-times-a-day dosing. These delivery systems make the drug work better, says James M. Swanson, PhD, an ADHD researcher at the University of California, Irvine.
Swanson says that other new drugs now in development differ from Ritalin in that they target other brain chemicals that affect executive function. It is hoped that one day different drugs -- or different combinations of drugs - will allow doctors to fine-tune ADHD treatment.
"We need to be more aware of integrated, targeted, and synchronized treatments," Tannock says. "As we begin to understand more the neurological networks, we will be better able to target ADHD treatment."