INFORMATION: There is an organization called CHADD here: CHADD Live | Home Page
My son was diagnosed at age 8.
DIET: We did all the diet changes (and still live with them) but I didn't see a change really. (they are healthy changes, food from scratch, allergy awareness, little sugar)
SKILLS: Organization.....is a skill, which can be learned.
DISTRACTIONS: Lack of focus, distractibility in ADHD, has to do with a part of the brain. That part of the brain doesn't effectively use the glucose available as well as non-ADHD children/adults. This was shown in brain scans.
STRUCTURE and ATTENTION: I've found giving them structure helps (chore charts, attention from adults, hold them responsible) and will not cure the problem. By the time they are adults they've learned the coping skills they need to pay attention in a manner they can pay attention.
INTELLIGENCE: ADHD is not a measure of intelligence, a person can be ADHD and have a very high IQ or a very low one, that is not relevant to ADHD.
My son is now 26, good job, and happy life (in addition to his amazing wit, charisma and good attitude toward life). There have always been ADHD people, and they find their niche. My son likes driving around all day doing service calls and managing people--the constant interruptions to his day and physical movement are great for him, he's very successful.