More research theories are there about ADHD, and a few of them are actually based in fact. I recently went through some information from the National Institutes of Mental Health that I found really interesting.
First off, brain imaging using MRI (magnetic resonance imaging) actually shows differences between the brains of kids with ADHD and kids without ADHD.
There also does seem to be a sugar link in ADHD, but not what many people suspect. In adults with ADHD, the areas of the brain that control attention use less glucose and appear less active than the brains of people without ADHD.
Research also shows a genetic link in ADHD, though it's still not clear exactly what causes Attention Deficit Hyperactivity Disorder.
What is clear is that children who have ADHD usually have at least one close relative with ADHD. At least one-third of fathers with ADHD have an ADHD child.
What's even more convincing is that it seems to run in twin pairs--if one identical twin has ADHD, the other usually does, too. In fact, I know a pair of identical twins with ADHD. Their mother has her hands full, I can tell you!
The final interesting point I found in the ADHD research from NIMH was that studies of young children (ages 7 to 9) show that ADHD medication is more effective than behavioral therapies alone in controlling the "core symptoms" of ADHD-- inattention, hyperactivity/impulsiveness, and agression. When it came to ADHD-related anxiety, school performance and social skills, the combination of ADHD medications and behavioral therapy was more effective than either alone.
It is very important that to note that behavioral therapy for ADHD was effective, just that it was more successful when combined with medication, based on these studies. You can read the ADHD research summary by referring to on the National Institutes of Mental Health on the internet.